EXECUTION VERSION Atkore International Group Inc. 7,234,838 Shares of Common Stock Underwriting Agreement May 16, 2018 Credit Suisse Securities (USA) LLC As representatives (the “Representatives”) of the several Underwriters named in Schedule I...

EXECUTION VERSION Atkore International Group Inc. 7,234,838 Shares of Common Stock Underwriting Agreement May 16, 2018 Credit Suisse Securities (USA) LLC As representatives (the “Representatives”) of the several Underwriters named in Schedule I hereto, c/o Credit Suisse Securities (USA) LLC Eleven Madison Avenue, New York, N.Y. 10010-3629 Ladies and Gentlemen: The stockholders named in Schedule V hereto (the “Selling Stockholders”), as stockholders of Atkore International Group Inc., a Delaware corporation (the “Company”), propose, subject to the terms and conditions stated herein, to issue and sell to the Underwriters named in Schedule I hereto (the “Underwriters”) an aggregate of 7,234,838 shares (the “Shares”) of common stock, $0.01 par value (“Stock”) of the Company. To the extent there are no additional Underwriters listed in Schedule I other than you, the term Representatives as used herein shall mean you, as Underwriter, and the terms Representatives and Underwriters shall mean either the singular or plural as the context requires. 1. (a) The Company represents and warrants to, and agrees with, each of the Underwriters that: (i) A shelf registration statement on Form S-3 (File No. 333-219137) in respect of the Shares has been filed with the U.S. Securities and Exchange Commission (the “Commission”) and has been declared effective not earlier than three years prior to the date hereof; and no stop order suspending the effectiveness of such registration statement or any part thereof has been issued and no proceeding for that purpose has been initiated or threatened by the Commission, and no notice of objection of the Commission to the use of such registration statement or any post- effective amendment thereto pursuant to Rule 401(g)(2) under the Securities Act of 1933, as amended (the “Act”) has been received by the Company (the base prospectus filed as part of such registration statement, in the form in which it was filed with the Commission on November 30, 2017, is hereinafter called the “Base Prospectus”; any preliminary prospectus (including any preliminary prospectus supplement) relating to the Shares filed with the Commission pursuant to Rule 424(b) under the Act is hereinafter called a “Preliminary Prospectus”; the various parts of such registration statement, including all exhibits thereto and including any prospectus supplement relating to the Shares that is filed with the Commission and deemed by virtue of Rule 430B to be part of such registration statement, each as amended at the time such part of the registration statement became effective, are hereinafter collectively called the “Registration Statement”; the Base Prospectus, as amended and supplemented immediately prior to the Applicable Time (as defined in Section 1(c) hereof), is hereinafter called the “Pricing Prospectus”; the form of the final prospectus relating to the Shares filed with the Commission pursuant to Rule 424(b) under the Act in accordance with Section 5(a) hereof is hereinafter called the “Prospectus”; any reference herein to the Base Prospectus, the Pricing Prospectus, any Preliminary Prospectus or the Prospectus shall be deemed to refer to and include the documents incorporated by reference therein pursuant to Item 12 of Form S-3 under the Act, as of the date of such prospectus; any reference to any amendment or supplement to the Base Prospectus, any Preliminary Prospectus or the Prospectus shall be deemed to refer to and include any post-effective amendment to the Registration Statement, any prospectus supplement relating to the Shares filed with the Commission pursuant to Rule 424(b) under the Act and any documents filed under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and incorporated therein, in each case after the date of the Base US-DOCS\96969269.4

Prospectus, such Preliminary Prospectus, or the Prospectus, as the case may be; any reference to any amendment to the Registration Statement shall be deemed to refer to and include any annual report of the Company filed pursuant to Section 13(a) or 15(d) of the Exchange Act after the effective date of the Registration Statement that is incorporated by reference in the Registration Statement; and any “issuer free writing prospectus” as defined in Rule 433 under the Act relating to the Shares is hereinafter called an “Issuer Free Writing Prospectus”); (ii) No order preventing or suspending the use of any Preliminary Prospectus or any Issuer Free Writing Prospectus has been issued by the Commission, and each Preliminary Prospectus dated on or after December 15, 2017, at the time of filing thereof, conformed in all material respects to the requirements of the Act and the rules and regulations of the Commission thereunder, and did not contain an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading; provided, however, that this representation and warranty shall not apply to statements or omissions made in reliance upon and in conformity with information furnished in writing to the Company by an Underwriter through the Representatives expressly for use therein or by the Selling Stockholders expressly for use therein; provided further, that (x) the only information so furnished by an Underwriter shall be the information in the second sentence of the first paragraph under the heading “Underwriting— Commissions and Discounts,” the information in the first paragraph and the second paragraph under the heading “Underwriting—Stabilization and Short Positions” and the information under the heading “Underwriting—Electronic Distribution” contained in the Prospectus (collectively, the “Underwriter Information”) and (y) the only information so furnished by the Selling Stockholders shall be the name of each Selling Stockholder, the number of offered shares and the address and other information with respect to such Selling Stockholder included in the “Principal and Selling Stockholders” section of the Registration Statement, the Pricing Prospectus, the Prospectus or any Issuer Free Writing Prospectus (the “Selling Stockholder Information”); (iii) For the purposes of this Agreement, the “Applicable Time” is 4:15 p.m. (New York City time) on the date of this Agreement; the Pricing Prospectus, as supplemented by the Issuer Free Writing Prospectuses and the other information listed on Schedule II(c) hereto, taken together (collectively, the “Pricing Disclosure Package”), as of the Applicable Time, did not include any untrue statement of a material fact or omit to state any material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading; and each Issuer Free Writing Prospectus listed on Schedule II(a) or Schedule II(c) hereto does not conflict with the information contained in the Registration Statement, the Pricing Prospectus or the Prospectus and each such Issuer Free Writing Prospectus, as supplemented by and taken together with the Pricing Disclosure Package, as of the Applicable Time, did not include any untrue statement of a material fact or omit to state any material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading; provided, however, that this representation and warranty shall not apply to the Underwriter Information or the Selling Stockholder Information; (iv) The Registration Statement conforms, and the Prospectus and any further amendments or supplements to the Registration Statement and the Prospectus will conform, in all material respects to the requirements of the Act and the rules and regulations of the Commission thereunder and do not and will not, as of the applicable effective date as to each part of the Registration Statement and as of the applicable filing date as to the Prospectus and any amendment or supplement thereto, contain an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading (in the case of the Prospectus, in light of the circumstances under which they were made); provided, however, that this representation and warranty shall not apply to the Underwriter Information or the Selling Stockholder Information; (v) Neither the Company nor any of its subsidiaries has sustained, since the date of the latest audited financial statements included in the Pricing Prospectus, any material loss or 2 US-DOCS\96969269.4

material interference with its business from fire, explosion, flood or other calamity, whether or not covered by insurance, or from any labor dispute or court or governmental action, order or decree, otherwise than as set forth in or contemplated by the Pricing Disclosure Package; and, since the respective dates as of which information is given in the Registration Statement and the Pricing Prospectus, there has not been any material change in (i) the capital stock of the Company or its subsidiaries or (ii) long-term debt of the Company and its subsidiaries or any material adverse change, or any development involving a prospective material adverse change, in or affecting the general affairs, management, financial position, stockholders’ equity or results of operations of the Company and its subsidiaries, taken together as a whole, otherwise than as set forth or contemplated in the Pricing Disclosure Package; (vi) The Company and its subsidiaries, taken together as a whole, have good title in fee simple to, or have valid rights to lease or otherwise use, all items of real property and title to, or valid rights to lease or otherwise use, all personal property, which are material to the business of the Company and its subsidiaries, taken as a whole (collectively, the “Business”), free and clear of all liens, encumbrances, claims and title defects (collectively, “Liens”) that would reasonably be expected to have a material adverse effect on the financial position, stockholders’ equity or results of operations of the Company and its subsidiaries, taken as a whole (a “Material Adverse Effect”), other than Liens disclosed, granted or to be granted to the lenders under or otherwise permitted by the agreements and instruments governing the Company’s existing indebtedness described in the Pricing Disclosure Package, as the same may be amended, supplemented, waived or otherwise modified from time to time, or refunded, refinanced, restructured, replaced, renewed, repaid, increased or extended from time to time (whether in whole or in part) and except as do not materially interfere with the use of such properties; (vii) Each of the Company and its subsidiaries listed on Schedule IV hereto (each, a “Designated Subsidiary” and collectively, the “Designated Subsidiaries”) (i) has been duly incorporated or organized and is validly existing in good standing under the laws of the jurisdiction of its incorporation or organization (to the extent the concept of good standing is applicable in the relevant jurisdiction), with power and authority to own its properties and conduct its business as described in the Pricing Prospectus; and (ii) has been duly qualified as a foreign corporation, partnership or limited liability company for the transaction of business and is in good standing (if applicable) under the laws of each other jurisdiction in which it owns or leases properties or conducts any business so as to require such qualification, except, in the case of clauses (i) and (ii), where the failure to be in good standing or to be so qualified or to have such power or authority would not reasonably be expected to have a Material Adverse Effect; (viii) The Company has an authorized capitalization as set forth in the Pricing Prospectus and all of the issued shares of capital stock of the Company, including the Shares to be sold pursuant to this Agreement, have been duly and validly authorized and issued and are fully paid and non-assessable and conform in all material respects to the description of the Stock contained in the Pricing Disclosure Package and the Prospectus; none of the outstanding shares of capital stock of the Company (including the Shares) were issued in violation of preemptive or other similar rights of any stockholder of the Company; and all of the issued shares of capital stock of each Designated Subsidiary of the Company have been duly and validly authorized and issued, are fully paid and non-assessable and, in each case, except as otherwise set forth in the Pricing Disclosure Package, are owned directly or indirectly by the Company, free and clear of all Liens other than the Liens disclosed, granted or to be granted under or otherwise permitted by agreements and instruments governing the existing indebtedness of the Company or its subsidiaries as described in the Pricing Disclosure Package, as the same may be amended, supplemented, waived or otherwise modified from time to time, or refunded, refinanced, restructured, replaced, renewed, repaid, increased or extended from time to time (whether in whole or in part); (ix) This Agreement has been duly authorized, executed and delivered by the Company; 3 US-DOCS\96969269.4

(x) The sale of the Shares and the compliance by the Company with, this Agreement and the consummation of the transactions contemplated herein will not (i) conflict with or result in a breach or violation of any of the terms or provisions of, or constitute a default under, any indenture, mortgage, deed of trust, loan agreement or other agreement or instrument to which the Company or any of its Designated Subsidiaries is a party or by which the Company or any of its Designated Subsidiaries is bound or to which any of the property or assets of the Company or any of its Designated Subsidiaries is subject; (ii) violate any provision of the certificate of incorporation or by-laws, or other organizational document, of the Company, or any of its Designated Subsidiaries; or (iii) violate any statute or any order, rule or regulation of any court or governmental agency or body having jurisdiction over the Company or any of its Designated Subsidiaries, except, in the case of clauses (i) and (iii), as would not reasonably be expected to have a Material Adverse Effect, in the case of each such clause, after giving effect to any consents, approvals, authorizations, orders, registrations, qualifications, waivers and amendments as will have been obtained or made as of the First Time of Delivery (as defined in Section 4(a) hereof); and no consent, approval, authorization, order, registration or qualification of or with any such court or governmental agency or body is required for the consummation by the Company of the transactions contemplated by this Agreement, except (A) for the registration under the Act of the Shares; (B) the approval by the Financial Industry Regulatory Authority (“FINRA”) of the underwriting terms and arrangements; (C) such consents, approvals, authorizations, orders, registrations or qualifications as may be required under state securities or Blue Sky laws in connection with the purchase and distribution of the Shares by the Underwriters; (D) as disclosed in the Pricing Disclosure Package; (E) such consents, approvals, authorizations, orders, registrations, qualifications, waivers, amendments or terminations as will have been obtained or made as of the First Time of Delivery; and (F) where the failure to obtain or make any such consent, approval, authorization, order, registration or qualification would not reasonably be expected to have a Material Adverse Effect; (xi) Neither the Company nor any of its Designated Subsidiaries is (i) in violation of its certificate of incorporation or by-laws, or other organizational document, as applicable; or (ii) in default in the performance or observance of any obligation, covenant or condition contained in any indenture, mortgage, deed of trust, loan agreement, lease or other agreement or instrument to which it is a party or by which it or any of its properties may be bound, except, in the case of clause (ii) above, for any such violation or default that would not reasonably be expected, individually or in the aggregate, to have a Material Adverse Effect; (xii) The statements set forth in the Pricing Prospectus and the Prospectus under the caption “Description of Capital Stock”, insofar as they purport to constitute a summary of the terms of the Stock, and under the caption “U.S. Federal Income Tax Considerations for Non-U.S. Holders”, insofar as they purport to describe the provisions of the laws and documents referred to therein, are accurate in all material respects; (xiii) Other than as set forth in the Pricing Disclosure Package, there are no legal or governmental proceedings pending to which the Company or any of its subsidiaries is a party or of which any property of the Company or any of its subsidiaries is subject that would, individually or in the aggregate, reasonably be expected to have a Material Adverse Effect; and, to the knowledge of the Company, no such proceedings are threatened by governmental authorities or by others; (xiv) The Company is not an “investment company”, as such term is defined in the Investment Company Act of 1940, as amended (the “Investment Company Act”); (xv) At the earliest time after the filing of the Registration Statement that the Company or another offering participant made a bona fide offer (within the meaning of Rule 164(h)(2) under the Act) of the Shares and at the date hereof, the Company was not and is not an “ineligible issuer” as defined in Rule 405 under the Act; 4 US-DOCS\96969269.4

(xvi) Deloitte & Touche LLP (“Deloitte”), who has audited certain consolidated financial statements of the Company included in the Pricing Disclosure Package, has advised the Company that it is an independent registered public accounting firm with respect to the Company as required by the Act and the rules and regulations of the Commission thereunder and the rules and regulations of the Public Company Accounting Oversight Board (United States); (xvii) The Company maintains a system of internal accounting controls that is sufficient to provide reasonable assurance that (i) transactions are executed in accordance with management’s general or specific authorizations; (ii) transactions are recorded as necessary to permit preparation of financial statements in conformity with generally accepted accounting principles in the United States (“GAAP”) and to maintain asset accountability; (iii) access to assets is permitted only in accordance with management’s general or specific authorization; (iv) the recorded accountability for assets is compared with the existing assets at reasonable intervals and appropriate action is taken with respect to any differences; and (v) interactive data in eXtensible Business Reporting Language filed as exhibits to the Registration Statement fairly present in all material respects the information required to be stated therein in accordance with the Commission’s rules and guidelines applicable thereto; (xviii) Since the date of the latest audited financial statements included or incorporated by reference in the Pricing Disclosure Package, to the knowledge of the Company, there has been no change in the Company’s internal accounting controls that has materially adversely affected, or would reasonably be expected to materially adversely affect, the Company’s internal accounting controls; (xix) The Company maintains disclosure controls and procedures (as such term is defined in Rule 13a-15(e) under the Securities Exchange Act of 1934, as amended (the “Exchange Act”)) that comply with the requirements of the Exchange Act; such disclosure controls and procedures have been designed to ensure that material information relating to the Company and its subsidiaries is made known to the Company’s principal executive officer and principal financial officer by others within those entities; and such disclosure controls and procedures are effective at a reasonable assurance level; (xx) The consolidated financial statements of the Company included in the Registration Statement, the Pricing Disclosure Package and the Prospectus present fairly in all material respects the financial position of the Company and its consolidated subsidiaries, as of the dates indicated and the results of its operations and the changes in its stockholders’ equity and cash flows for the periods specified (subject to the omission of footnotes and normal year-end audit and other adjustments, as to any unaudited financial statements of the Company); such consolidated financial statements have been prepared in accordance with GAAP applied on a consistent basis, subject to the limitations set out in the notes to the respective financial statements of the Company included in the Registration Statement, the Pricing Disclosure Package and the Prospectus; and any supporting schedules included in the Registration Statement present fairly the information required to be stated therein; (xxi) There are no persons with registration rights or other similar rights to have any securities registered for sale pursuant to the Registration Statement or otherwise registered for sale or sold by the Company under the Act pursuant to this Agreement other than those rights that have been waived or rights which have been disclosed in the Registration Statement, the Pricing Disclosure Package and the Prospectus; (xxii) Neither the Company nor any of its subsidiaries nor, to the knowledge of the Company, any director, officer or employee of the Company or any of its subsidiaries has (i) used any corporate funds for any unlawful contribution, gift, entertainment or other unlawful expense relating to political activity; (ii) made or taken an act in furtherance of an offer, promise or authorization of any direct or indirect unlawful payment or benefit to any foreign or domestic government official or employee, including of any government-owned or controlled entity or of a public international organization, or any person acting in an official capacity for or on behalf of 5 US-DOCS\96969269.4

any of the foregoing; (iii) violated or is in violation of any provision of the U.S. Foreign Corrupt Practices Act of 1977, as amended (the “FCPA”), or committed an offence under the Xxxxxxx Xxx 0000 of the United Kingdom; or (iv) made any bribe, unlawful rebate, payoff, influence payment, kickback or other unlawful payment; and the Company has instituted a policy designed to promote and ensure compliance with the FCPA; (xxiii) The Company and its subsidiaries have not, nor, to the knowledge of the Company, has any director, officer or employee of the Company or any of its subsidiaries taken any action (including the participation of the Company and its subsidiaries in the offering of the Shares), directly or indirectly, that would result in a violation by such person of applicable anti- money laundering laws, including applicable and federal, state, international, foreign or other laws, regulations or government guidance regarding anti-money laundering (including, the USA PATRIOT ACT of 2001) rules, regulations or guidelines issued, administered or enforced by any governmental agency (collectively, the “Anti-Money Laundering Laws”); and no action, suit or proceeding by or before any court or governmental agency, authority or body or any arbitrator involving the Company or any of its subsidiaries with respect to the Anti-Money Laundering Laws is, to the knowledge of the Company, pending or threatened; (xxiv) Neither the Company nor any of its subsidiaries nor, to the knowledge of the Company, any director, officer or employee of the Company or any of its subsidiaries is currently subject to any U.S. sanctions (“Sanctions”) administered by the Office of Foreign Assets Control of the U.S. Department of the Treasury (“OFAC”), nor is the Company or any of its subsidiaries located, organized or resident in a country or territory that is the subject or target of comprehensive Sanctions (namely, Crimea, Cuba, Iran, North Korea, Sudan and Syria, each a “Sanctioned Country”); (xxv) The Company and each of its subsidiaries collectively own, or have the legal right to use, all United States patents, patent applications, trademarks, trademark applications, trade names, copyrights, technology, know-how and processes necessary for them to conduct the Business as currently conducted (the “Intellectual Property”), except for those the failure to own or have such legal right to use would not be reasonably expected to have a Material Adverse Effect. Except as disclosed in the Pricing Disclosure Package, no claim has been asserted in writing and is pending by any person against the Company or any of its subsidiaries challenging or questioning the use of any such Intellectual Property or the validity or effectiveness of any such Intellectual Property, nor has the Company received written notice of any such claim, and, to the knowledge of the Company, the use of such Intellectual Property by the Company and its subsidiaries does not infringe on the rights of any person, except for such claims and infringements which, in the aggregate, would not be reasonably expected to have a Material Adverse Effect; (xxvi) Except as disclosed in the Pricing Disclosure Package, there is no claim or environmental remediation project pending or, to the knowledge of the Company, threatened under any Environmental Law (as defined below) against the Company or its subsidiaries that would reasonably be expected to have a Material Adverse Effect. The term “Environmental Law” means any federal, local or foreign law, regulation, ordinance, order, judgment decree, permit or rule (including rule of common law) now in effect governing pollution, or actual or alleged exposure to, hazardous or toxic materials, substances or wastes, including but not limited to, asbestos or asbestos-containing materials; (xxvii) The Company has filed or caused to be filed all United States federal income tax returns and all other material tax returns which are required to be filed or have requested extensions thereof and has paid (i) all taxes shown to be due and payable on such returns; and (ii) all taxes shown to be due and payable on any assessments of which it has received notice made against it or any of its property and all other taxes, fees or other charges imposed on it or any of its property by any governmental authority (other than any (A) taxes, fees or other charges with respect to which the failure to pay, in the aggregate, would not reasonably be expected to have a Material Adverse Effect; or (B) taxes, fees or other charges the amount or validity of which are 6 US-DOCS\96969269.4

currently being contested in good faith by appropriate proceedings diligently conducted and with respect to which reserves in conformity with GAAP have been provided on the books of the Company, as the case may be). No tax lien has been filed, and no claim is being asserted, with respect to any such tax, fee or other charge, against the Company or any of its Designated Subsidiaries, except for liens or charges that would not, individually or in the aggregate, be reasonably expected to have a Material Adverse Effect; (xxviii) (i) The Company and its subsidiaries collectively possess all licenses, permits, certificates, consents, orders, approvals and other authorizations from, and have made all declarations and filings with, all federal, state and other governmental authorities, presently required or necessary to own or lease, as the case may be, and to operate their properties and to carry on the Business as set forth in the Pricing Disclosure Package (“Permits”), except as disclosed in the Pricing Disclosure Package or where the failure to possess, make or obtain such Permits (by possession, declaration or filing) would not, individually or in the aggregate, reasonably be expected to have a Material Adverse Effect; (xxix) The Company has not taken, directly or indirectly, any action designed to or that could reasonably be expected to cause or result in the stabilization or manipulation of the price of the Shares; (xxx) There is no strike or labor dispute, slowdown or work stoppage with the employees of the Company or any of its subsidiaries that is pending or, to the knowledge of the Company, threatened, except as would not reasonably be expected to have a Material Adverse Effect; and (xxxi) The Company and its subsidiaries collectively carry insurance (including self- insurance, if any) in such amounts and covering such risks as in the Company’s reasonable determination is adequate for the conduct of its business and the value of its properties, except where the failure to carry such insurance would not reasonably be expected to have a Material Adverse Effect. (b) Each of the Selling Stockholders, severally and not jointly represents and warrants to, and agrees with, each Underwriter and the Company that: (i) All consents, approvals, authorizations and orders necessary for the execution and delivery by such Selling Stockholder of this Agreement, and, in the case of the Selling Stockholders set forth on Part B of Schedule V (the “Specified Selling Stockholders”), the Custody Agreement (as defined below), and for the sale and delivery of the Shares to be sold by such Selling Stockholder hereunder, have been obtained, or will be obtained prior to the First Time of Delivery; and such Selling Stockholder has full right, power and authority to enter into this Agreement and, in the case of the Specified Selling Stockholders, the Custody Agreement, and to sell, assign, transfer and deliver the Shares to be sold by such Selling Stockholder hereunder, except for such consents, approvals, authorizations and orders as would not impair in any material respect the consummation of such Selling Stockholder’s obligations hereunder; (ii) The sale of the Shares to be sold by such Selling Stockholder hereunder and the compliance by such Selling Stockholder with this Agreement and, in the case of the Specified Selling Stockholders, the Custody Agreement, and the consummation of the transactions herein contemplated will not (A) conflict with or result in a breach or violation of any of the terms or provisions of, or constitute a default under, any indenture, mortgage, deed of trust, loan agreement or other agreement or instrument to which such Selling Stockholder is a party or by which such Selling Stockholder is bound or to which any of the property or assets of such Selling Stockholder is subject; (B) violate the provisions of any organizational or similar documents pursuant to which such Selling Stockholder was formed; or (C) violate any statute or any order, rule or regulation of any court or governmental agency or body having jurisdiction over such Selling Stockholder or the property of such Selling Stockholder, except in the case of clause (A) or clause (C), for such 7 US-DOCS\96969269.4

conflicts, breaches, violations or defaults as would not impair in any material respect the consummation of such Selling Stockholder’s obligations hereunder and thereunder; (iii) Immediately prior to each Time of Delivery (as defined in Section 4(a) hereof) such Selling Stockholder will be the beneficial or record holder of the Shares to be sold by such Selling Stockholder hereunder with full dispositive power thereover, and holds, and will hold, such Shares free and clear of all liens, encumbrances, equities or claims; and, upon delivery of such Shares and payment therefor pursuant hereto, assuming that the Underwriters have no notice of any adverse claims (within the meaning of Section 8-105 of the New York Uniform Commercial Code as in effect in the State of New York from time to time (the “UCC”)) to such Shares, each Underwriter will acquire a valid security entitlement (within the meaning of Section 8-102(a)(17) of the UCC) to such Shares purchased by such Underwriter, and no action (whether framed in conversion, replevin, constructive trust, equitable lien or other theory) based on an adverse claim (within the meaning of Section 8-105 of the UCC) to such security entitlement may be asserted against such Underwriter; (iv) On or prior to the date of the Pricing Prospectus, such Selling Stockholder (unless listed in Part B of Schedule V) has executed and delivered to the Underwriters an agreement substantially in the form of Annex III hereto. (v) Such Selling Stockholder has not taken and will not take, directly or indirectly, any action which is designed to or which has constituted or which would reasonably be expected to cause or result in stabilization or manipulation of the price of any equity security, or any securities convertible into, or exchangeable for, or that represent a right to receive an equity security or any equity-linked securities of the Company to facilitate the sale or resale of the Shares; (vi) To the extent, but only to the extent, that any statements made in the Registration Statement, the Pricing Prospectus, the Prospectus, any Issuer Free Writing Prospectus or any amendment or supplement thereto are made in reliance upon and in conformity with the Selling Stockholder Information, the Registration Statement, the Pricing Prospectus, the Prospectus, any Issuer Free Writing Prospectus do not and will not contain any untrue statement of a material fact or omit to state any material fact required to be stated therein or necessary to make the statements therein not misleading (in the case of the Pricing Prospectus, the Prospectus, or any amendment or supplement thereto, and any Issuer Free Writing Prospectus, in light of the circumstances under which they were made); (vii) In order to document the Underwriters’ compliance with the reporting and withholding provisions of the Tax Equity and Fiscal Responsibility Act of 1982 with respect to the transactions herein contemplated, each of the Selling Stockholders will deliver to you prior to or at the First Time of Delivery a properly completed and executed United States Treasury Department Form W-9 (or other applicable form or statement specified by Treasury Department regulations in lieu thereof); (viii) Such Specified Selling Stockholder has delivered a duly executed stock power authorizing the transfer of the Shares to be sold by such Specified Selling Stockholder (the “Stock Power”) to American Stock Transfer & Trust Company, LLC, as custodian (the “Custodian”) under a Custody Agreement relating to such Shares, in the form previously furnished to you, duly executed and delivered by such Specified Selling Stockholders to the Custodian, and such Specified Selling Stockholder has duly executed and delivered a Power of Attorney, in the form previously furnished to you, appointing CD&R Allied Holdings, L.P. as such Specified Selling Stockholder’s attorney-in-fact (the “Attorney-in-Fact”) with authority to execute and deliver this Agreement on behalf of such Specified Selling Stockholder, to determine the purchase price to be paid by the Underwriter to the Specified Selling Stockholder as provided herein, to authorize the delivery of the Shares to be sold by such Specified Selling Stockholder hereunder and otherwise to act on behalf of such Specified Selling Stockholder in connection with the transactions contemplated by this Agreement and the Custody Agreement; 8 US-DOCS\96969269.4

(ix) Such Specified Selling Stockholder agrees that the Shares covered by the Stock Powers held in custody for such Specified Selling Stockholder under the Custody Agreement are subject to the interests of the Underwriters hereunder, and that the arrangements made by such Specified Selling Stockholder for such custody, and the appointment by such Specified Selling Stockholder of the Attorney-in-Fact by the Power of Attorney, are to that extent irrevocable; and (x) Such Selling Stockholder is not (1) an employee benefit plan subject to Title I of the Employee Retirement Income Security Act of 1974, as amended (“ERISA”), (2) a plan or account subject to Section 4975 of the Internal Revenue Code of 1986, as amended (the “Code”) or (3) an entity deemed to hold “plan assets” of any such plan or account under Section 3(42) of ERISA, 29 C.F.R. 2510.3-101, or otherwise. 2. Subject to the terms and conditions herein set forth, each of the Selling Stockholders agree, severally and not jointly, to sell to each of the Underwriters, and each of the Underwriters agrees, severally and not jointly, to purchase from the Selling Stockholders at a purchase price per share of $19.91, the aggregate number of Shares to be purchased by such Underwriter as set forth opposite the name of such Underwriter in Schedule I hereto. 3. Upon the authorization by the Selling Stockholders or their Attorney-in-Fact of the release of the Shares, the several Underwriters propose to offer the Shares for sale upon the terms and conditions set forth in the Prospectus. 4. (a) The Shares to be purchased by each Underwriter hereunder, in book-entry form, and in such authorized denominations and registered in such names as the Representatives may request upon at least forty-eight hours’ prior notice to the Selling Stockholders shall be delivered by or on behalf of the Selling Stockholders to the Representatives, through the facilities of The Depository Trust Company (“DTC”), for the account of such Underwriter, against payment by or on behalf of such Underwriter of the purchase price therefor by wire transfer of Federal (same-day) funds to the account specified by the Selling Stockholder listed on Part A of Schedule V and the Custodian to the Representatives at least twenty-four hours in advance. The time and date of such delivery and payment shall be, with respect to the Shares, 9:30 a.m., New York time, on May 21, 2018 or such other time and date as the Representatives, the Selling Stockholder listed on Part A of Schedule V and the Attorney-in-Fact may agree upon in writing. Such time and date for delivery of the Shares is herein called the “Time of Delivery”. (b) The documents to be delivered at the Time of Delivery by or on behalf of the parties hereto pursuant to Section 8 hereof, including the cross-receipt for the Shares and any additional documents requested by the Representatives pursuant to Section 8(j) and Section 8(k) hereof will be delivered at the offices of Debevoise & Xxxxxxxx LLP, 000 Xxxxx Xxxxxx, Xxx Xxxx, Xxx Xxxx 00000 (the “Closing Location”), and the Shares will be book-entry delivery at the Time of Delivery. A meeting will be held at the Closing Location at 2:00 p.m., New York City time, on the New York Business Day next preceding the Time of Delivery, at which meeting the final drafts of the documents to be delivered pursuant to the preceding sentence will be available for review by the parties hereto. For the purposes of this Section 4, “New York Business Day” shall mean each Monday, Tuesday, Wednesday, Thursday and Friday which is not a day on which banking institutions in New York are generally authorized or obligated by law or executive order to close. 5. The Company agrees with each of the Underwriters: (a) To prepare the Prospectus in a form approved by the Representatives and to file such Prospectus pursuant to Rule 424(b) under the Act not later than the Commission’s close of business on the second business day following the execution and delivery of this Agreement, or, if applicable, such earlier time as may be required by Rule 430A(a)(3) under the Act; to make no further amendment or any supplement to the Registration Statement or the Prospectus prior to the last Time of Delivery without the Representatives’ consent which shall not be unreasonably withheld; to advise the Representatives, promptly after it receives notice thereof, of the time when any amendment to the Registration Statement has been filed or becomes effective or any amendment or supplement to the Prospectus has been filed and to furnish the Representatives with copies thereof; to file promptly all material required to be filed by the Company with the Commission pursuant to Rule 433(d) under the Act; to file promptly all reports and definitive 9 US-DOCS\96969269.4

proxy or information statements required to be filed by the Company with the Commission pursuant to Section 13(a), 13(c), 14 or 15(d) of the Exchange Act subsequent to the date of the Prospectus and for so long as the delivery of a prospectus (or in lieu thereof, the notice referred to in Rule 173(a) under the Act) is required in connection with the offering or sale of the Shares; to advise the Representatives, promptly after it receives notice thereof, of the issuance by the Commission of any stop order or of any order preventing or suspending the use of any Preliminary Prospectus or other prospectus in respect of the Shares, of the suspension of the qualification of the Shares for offering or sale in any jurisdiction, of the initiation or threatening of any proceeding for any such purpose or pursuant to Section 8A of the Act, or of any request by the Commission for the amending or supplementing of the Registration Statement or the Prospectus or for additional information; and, in the event of the issuance of any stop order or of any order preventing or suspending the use of any Preliminary Prospectus or other prospectus or suspending any such qualification, to promptly use its best efforts to obtain the withdrawal of such order; (b) If required by Rule 430B(h) under the Act, to prepare a form of prospectus in a form approved by the Underwriters and to file such form of prospectus pursuant to Rule 424(b) under the Act not later than may be required by Rule 424(b) under the Act; and to make no further amendment or supplement to such form of prospectus which shall be disapproved by the Underwriters promptly after reasonable notice thereof; (c) Promptly from time to time to take such action as the Representatives may reasonably request to qualify the Shares for offering and sale under the securities laws of such jurisdictions as the Representatives may reasonably request and to comply with such laws so as to permit the continuance of sales and dealings therein in such jurisdictions for as long as may be necessary to complete the distribution of the Shares, provided that in connection therewith the Company shall not be required to qualify as a foreign corporation or to file a general consent to service of process in any jurisdiction; (d) Prior to 10:00 a.m., New York City time, on the second New York Business Day following the date of this Agreement and from time to time, to furnish the Underwriters with written and electronic copies of the Prospectus (and to the extent the Prospectus is not available, the Pricing Disclosure Package) in New York City in such quantities as the Representatives may reasonably request, and, if the delivery of a prospectus (or in lieu thereof, the notice referred to in Rule 173(a) under the Act) is required at any time prior to the expiration of nine months after the time of issue of the Prospectus (or the Pricing Disclosure Package, as applicable) in connection with the offering or sale of the Shares and if at such time any event shall have occurred as a result of which the Prospectus (or the Pricing Disclosure Package, as applicable) as then amended or supplemented would include an untrue statement of a material fact or omit to state any material fact necessary in order to make the statements therein, in light of the circumstances under which they were made when such Prospectus (or in lieu thereof, the notice referred to in Rule 173(a) under the Act or, as applicable, the Pricing Disclosure Package) is delivered, not misleading, or, if for any other reason it shall be necessary during such same period to amend or supplement the Prospectus or to file under the Exchange Act any document incorporated by reference therein (or Pricing Disclosure Package, as applicable) in order to comply with the Act or the Exchange Act, to notify the Representatives and upon the Representatives’ request to file such document and prepare and furnish without charge to each Underwriter and to any dealer in securities as many written and electronic copies as the Representatives may from time to time reasonably request of an amended Prospectus (or Pricing Disclosure Package, as applicable) or a supplement to the Prospectus (or Pricing Disclosure Package, as applicable) which will correct such statement or omission or effect such compliance; and in case any Underwriter is required to deliver a prospectus (or in lieu thereof, the notice referred to in Rule 173(a) under the Act) in connection with sales of any of the Shares at any time nine months or more after the time of issue of the Prospectus, upon the Representatives’ request but at the expense of such Underwriter, to prepare and deliver to such Underwriter as many written and electronic copies as the Representatives may request of an amended or supplemented Prospectus complying with Section 10(a)(3) of the Act; (e) To make generally available to its security holders as soon as practicable, but in any event not later than sixteen months after the effective date of the Registration Statement (as defined in Rule 158(c) under the Act), an earnings statement of the Company and its subsidiaries (which need not be 10 US-DOCS\96969269.4

audited) complying with Section 11(a) of the Act and the rules and regulations of the Commission thereunder (including, at the option of the Company, Rule 158); (f) During the period beginning from the date hereof and continuing to and including the date 30 days after the date of the Prospectus (the “Lock-Up Period”), not to (i) offer, sell, contract to sell, pledge, grant any option to purchase, make any short sale or otherwise transfer or dispose of, directly or indirectly, or file with the Commission a registration statement under the Act relating to, any securities of the Company that are substantially similar to the Shares, including but not limited to any options or warrants to purchase shares of Stock or any securities that are convertible into or exchangeable for, or that represent the right to receive, Stock or any such substantially similar securities or publicly disclose the intention to make any offer, sale, pledge, disposition or filing, or; (ii) enter into any swap or other agreement that transfers, in whole or in part, any of the economic consequences of ownership of the Stock or any such other securities, whether any such transaction described in clause (i) or (ii) above is to be settled by delivery of Stock or such other securities, in cash or otherwise other than (A) the Shares to be sold hereunder, (B) any shares of Stock issued by the Company upon the exercise of an option or warrant or the conversion; of a security outstanding on the date hereof and referred to in the Registration Statement, Pricing Disclosure Package or the Prospectus; (C) any shares of Stock issued or options to purchase Stock or restricted stock units, performance shares, performance units, stock appreciation rights, dividend equivalents, deferred share units or other Stock-based awards granted pursuant to employee benefit or compensation plans of the Company and referred to in the Registration Statement, Pricing Disclosure Package or the Prospectus; (D) any shares of Stock or restricted stock units, performance shares, performance units, stock appreciation rights, dividend equivalents, deferred share units or other Stock- based awards issued pursuant to any employee stock purchase plan, non-employee director stock plan or dividend reinvestment plan and referred to in the Registration Statement, Pricing Disclosure Package or the Prospectus; or (E) the filing of any registration statement on Form S-8, or (F) the entry into an agreement providing for the issuance of Stock or any securities convertible into or exercisable for Stock, and the issuance of any such securities pursuant to such an agreement, in connection with (i) the acquisition by the Company or any of its subsidiaries of the securities, business, property or other assets of another person or entity, including pursuant to an employee benefit plan assumed by the Company in connection with such acquisition, or (ii) joint ventures, commercial relationships or other strategic transactions, and the issuance of any such securities pursuant to any such agreement, provided that the aggregate number of shares issued or issuable pursuant to this clause (F) does not exceed 10% of the outstanding shares of Stock and prior to any such issuance each recipient of any such securities shall have executed and delivered to the Representatives an agreement substantially in the form of Annex III hereto), without having received the prior written waiver from the Representatives; and (g) To use its reasonable best efforts to maintain the listing of the Shares for trading, on the New York Stock Exchange (the “Exchange”). 6. (a) The Company represents and agrees that, without the prior consent of the Representatives, it has not made and will not make any offer relating to the Shares that would constitute a “free writing prospectus” as defined in Rule 405 under the Act; each of the Selling Stockholders represents and agrees that, without the prior written consent of the Company and the Representatives, it has not made and it will not make any offer relating to the Shares that would constitute a free writing prospectus; and each Underwriter, severally and not jointly, represents and agrees that, without the prior consent of the Company and the Representatives, it has not made and will not make any offer relating to the Shares that would constitute a free writing prospectus that would require a filing under the Act; any such free writing prospectus the use of which has been consented to by the Company and the Representatives is listed on Schedule II(a) and Schedule II(c) hereto; (b) The Company has complied and will comply with the requirements of Rule 433 under the Act applicable to any Issuer Free Writing Prospectus, including timely filing with the Commission or retention where required and legending; and (c) The Company agrees that if at any time following issuance of an Issuer Free Writing Prospectus any event occurred or occurs as a result of which such Issuer Free Writing Prospectus would 11 US-DOCS\96969269.4

conflict with the information in the Registration Statement, the Pricing Prospectus or the Prospectus or would include an untrue statement of a material fact or omit to state any material fact necessary in order to make the statements therein, in the light of the circumstances then prevailing, not misleading, the Company will give notice thereof as soon as reasonably practicable to the Representatives and, if requested by the Representatives, will prepare and furnish without charge to each Underwriter an Issuer Free Writing Prospectus or other document which will correct such conflict, statement or omission; provided, however, that this representation and warranty shall not apply to the Underwriter Information. 7. The Company covenants and agrees with the several Underwriters that (a) the Company will pay or cause to be paid the following: (i) the fees, disbursements and expenses of the Company’s counsel and accountants in connection with the registration of the Shares under the Act and all other expenses in connection with the preparation, printing, reproduction and filing of the Registration Statement, any Preliminary Prospectus, any Issuer Free Writing Prospectus and the Prospectus and amendments and supplements thereto and the mailing and delivering of copies thereof to the Underwriters and dealers; (ii) the cost of printing or producing any Agreement among Underwriters, this Agreement, the Blue Sky Memorandum, closing documents (including any compilations thereof) and any other documents in connection with the offering, purchase, sale and delivery of the Shares; (iii) up to $15,000 in connection with the qualification of the Shares for offering and sale under state securities laws as provided in Section 5(b) hereof, including the fees and disbursements of counsel for the Underwriters in connection with such qualification and in connection with the Blue Sky survey; (iv) all fees and expenses in connection with listing the Shares on the Exchange; (v) the costs, fees and expenses incurred by the Underwriters in connection with determining their compliance with the rules and regulations of FINRA related to the Underwriters’ participation in the offering and distribution of the Shares, including any related filing fees and the legal fees of, and disbursements by, counsel to the Underwriters in an amount not to exceed $25,000; (vi) the cost of preparing stock certificates; if applicable; (vii) the cost and charges of any transfer agent or registrar; (viii) the travel expenses incurred by or on behalf of representatives of the Company in connection with attending or hosting meetings with prospective purchasers of the Stock and expenses associated with any electronic road show (it being understood that the Underwriters, collectively, shall bear one-half of the costs associated with any chartered aircraft); (ix) all expenses (except underwriter discounts and commissions) incident to the sale and delivery of the Shares to be sold by the Selling Stockholders to the Underwriters hereunder; (x) any fees and expenses of counsel for the Selling Stockholders listed on Part A of Schedule V; and (xi) all other costs and expenses incident to the performance of its obligations hereunder which are not otherwise specifically provided for in this Section. Except as otherwise set forth in clause (ix) of the immediately preceding sentence, each of the Selling Stockholders covenants that it will pay or cause to be paid all taxes incident to the sale and delivery of the Shares to be sold by such Selling Stockholder to the Underwriters hereunder; provided, that, the Representatives agree to pay New York State stock transfer tax, and the Selling Stockholders agree, severally and not jointly, to reimburse the Representatives for associated carrying costs if such tax payment is not rebated on the day of payment and for any portion of such tax payment not rebated. The provisions of this Section shall not affect any agreement that the Company and the Selling Stockholders may make or have for the sharing of such costs and expenses. It is understood, however, that the Company shall bear, and the Selling Stockholders shall not be required to pay or to reimburse the Company for, the cost of any other matters not directly relating to the sale and purchase of the Shares pursuant to this Agreement, and that, except as provided in this Section, and Sections 9 and 12 hereof, the Underwriters will pay all of their own costs and expenses, including the fees of their counsel, stock transfer taxes on resale of any of the Shares by them, and any advertising expenses connected with any offers they may make. Notwithstanding anything to the contrary herein, if the sale of all of the Firm Shares pursuant to this Agreement is not consummated for any reason (including, without limitation, due to any termination of this Agreement or due to the failure of any conditions precedent thereto to be satisfied or waived), then the Underwriter Reimbursement Amount will not be due or payable. 8. The obligations of the Underwriters hereunder shall be subject, in their discretion, to the condition that all representations and warranties and other statements of the Company and the Selling Stockholders herein are, as of the date of this Agreement and at and as of the Time of Delivery, true and correct, the condition that the Company and the Selling Stockholders shall have performed all of its obligations hereunder theretofore to be performed, and the following additional conditions. (a) The Prospectus shall have been filed with the Commission pursuant to Rule 424(b) under the Act within the applicable time period prescribed for such filing by the rules and regulations under the Act and in accordance with Section 5(a) hereof; all material required to be filed by the Company pursuant 12 US-DOCS\96969269.4

to Rule 433(d) under the Act shall have been filed with the Commission within the applicable time period prescribed for such filing by Rule 433; no stop order suspending the effectiveness of the Registration Statement or any part thereof shall have been issued and no proceeding for that purpose shall have been initiated or threatened by the Commission; and no notice of objection of the Commission to the use of the Registration Statement or any post-effective amendment thereto pursuant to Rule 401(g)(2) under the Act shall have been received; no stop order suspending or preventing the use of the Prospectus or any Issuer Free Writing Prospectus shall have been initiated or threatened by the Commission; and all requests for additional information on the part of the Commission shall have been complied with to the Representatives’ reasonable satisfaction; (b) Xxxxxx & Xxxxxxx LLP, counsel for the Underwriters, shall have furnished to the Representatives such written opinion and negative assurance letter, dated the Time of Delivery, in form and substance satisfactory to the Representatives; (c) Debevoise & Xxxxxxxx LLP, counsel for the Company, shall have furnished to the Representatives its written opinion and negative assurance letter, substantially in the forms set forth in Annex I-A and Annex I-B hereto, each dated the Time of Delivery; (d) Xxxxxx X. Xxxxx, General Counsel for the Company, shall have furnished to you a certificate, substantially in the form set forth in Annex I-C hereto, dated the Time of Delivery; (e) Debevoise & Xxxxxxxx LLP, New York counsel for the Selling Stockholder listed on Part A of Schedule V, shall have furnished to the Representatives its written opinion with respect to matters of New York law, substantially in the form set forth in Annex II hereto, dated the Time of Delivery; (f) Xxxxxx & Calder, Cayman counsel for the Selling Stockholder listed on Part A of Schedule V, shall have furnished to the Representatives its written opinion with respect to matters of Cayman Islands law, in form and substance satisfactory to the Representatives; (g) On the date of the Prospectus at a time prior to the execution of this Agreement, at 9:30 a.m., New York City time, on the effective date of any post-effective amendment to the Registration Statement filed subsequent to the date of this Agreement and also at the Time of Delivery, Deloitte shall have furnished to the Representatives a letter or letters, dated the respective dates of delivery thereof, in form and substance satisfactory to the Representatives; (h) (i) Neither the Company nor any of its subsidiaries shall have sustained since the date of the latest audited financial statements included in the Pricing Prospectus any loss or interference with its business from fire, explosion, flood or other calamity, whether or not covered by insurance, or from any labor dispute or court or governmental action, order or decree, otherwise than as set forth in or contemplated by the Pricing Disclosure Package; and (ii) since the respective dates as of which information is given in the Pricing Prospectus there shall not have been any change in the capital stock or long-term debt of the Company and its subsidiaries or any change, or any development involving a prospective change, in or affecting the general affairs, management, financial position, stockholders’ equity or results of operations of the Company and its subsidiaries, taken together as a whole, otherwise than as set forth or contemplated in the Pricing Disclosure Package, the effect of which, in any such case described in clause (i) or (ii), is in the judgment of the Representatives so material and adverse as to make it impracticable or inadvisable to proceed with the public offering or the delivery of the Shares being delivered at the Time of Delivery on the terms and in the manner contemplated in the Prospectus; (i) On or after the Applicable Time (i) no downgrading shall have occurred in the rating accorded the Company’s debt securities by any “nationally recognized statistical rating organization”, as defined in Section 3(a)(62) of the Exchange Act, and (ii) no such organization shall have publicly announced that it has under surveillance or review, with possible negative implications, its rating of any of the Company’s debt securities; (j) On or after the Applicable Time there shall not have occurred any of the following: (i) a suspension or material limitation in trading in securities generally on the Exchange; (ii) a suspension or 13 US-DOCS\96969269.4

material limitation in trading in the Company’s securities on the Exchange; (iii) a general moratorium on commercial banking activities declared by either Federal or New York State authorities or a material disruption in commercial banking or securities settlement or clearance services in the United States; (iv) the outbreak or escalation of hostilities involving the United States or the declaration by the United States of a national emergency or war; or (v) the occurrence of any other calamity or crisis or any change in financial, political or economic conditions in the United States or elsewhere, if the effect of any such event specified in clause (iv) or (v) in the judgment of the Representatives makes it impracticable or inadvisable to proceed with the public offering or the delivery of the Shares being delivered at the Time of Delivery on the terms and in the manner contemplated in the Prospectus; (k) The Shares to be sold at the Time of Delivery shall have been duly listed on the Exchange; (l) The Company shall have obtained and delivered to the Underwriters executed copies of an agreement from each executive officer, director and stockholder of the Company listed on Schedule III hereto, substantially to the effect set forth in Annex III hereto in form and substance satisfactory to the Representatives; (m) The Company shall have complied with the provisions of Section 5(d) hereof with respect to the furnishing of prospectuses on the second New York Business Day following the date of this Agreement; (n) The Company shall have furnished or caused to be furnished to the Representatives at the Time of Delivery certificates of officers of the Company satisfactory to the Representatives as to the accuracy of the representations and warranties of the Company herein at and as of the Time of Delivery, as to the performance by the Company of all of its obligations hereunder to be performed at or prior to the Time of Delivery, as to such other matters as the Representatives may reasonably request, and the Company shall have furnished or caused to be furnished certificates as to the matters set forth in subsections (a) and (i) of this Section 8; and (o) The Selling Stockholders shall have furnished or caused to be furnished to the Representatives at the Time of Delivery certificates of an officer of each such Selling Stockholder satisfactory to the Representatives as to the accuracy of the representations and warranties of the Selling Stockholders herein at and as of the Time of Delivery, as to the performance by each such Selling Stockholder of all of its obligations hereunder to be performed at or prior to the Time of Delivery, as to such other matters as the Representatives may reasonably request. 9. (a) The Company will indemnify and hold harmless each Underwriter and each person, if any, who controls any Underwriter within the meaning of Section 15 of the Act or Section 20 of the Exchange Act and their respective officers, directors, employees and selling agents (including any affiliate of an Underwriter involved on behalf of the Underwriter in the distribution process for the Stock) against any losses, claims, damages or liabilities, joint or several, to which such Underwriter and/or such person may become subject, under the Act or otherwise, insofar as such losses, claims, damages or liabilities (or actions in respect thereof) arise out of or are based upon an untrue statement or alleged untrue statement of a material fact contained in the Registration Statement, the Base Prospectus, any Preliminary Prospectus, the Pricing Prospectus, the Prospectus, or any amendment or supplement thereto, any Issuer Free Writing Prospectus or any “issuer information” (in the case of either an Issuer Free Writing Prospectus or such “issuer information,” taken together with the Pricing Prospectus) filed or required to be filed pursuant to Rule 433(d) under the Act, or arise out of or are based upon the omission or alleged omission to state therein a material fact required to be stated therein or necessary to make the statements therein not misleading (in the case of the Preliminary Prospectus, the Pricing Prospectus, the Prospectus, or any amendment or supplement thereto, and any Issuer Free Writing Prospectus, in the light of the circumstances under which they were made), and will reimburse each Underwriter for any legal or other expenses reasonably incurred by such Underwriter in connection with investigating or defending any such action or claim as such expenses are incurred; provided, however, that the Company shall not be liable to any Underwriter in any such case to the extent that any such loss, claim, damage or liability arises out of or is based upon an untrue statement or alleged untrue statement or omission or alleged omission made in the 14 US-DOCS\96969269.4

Registration Statement, the Base Prospectus, any Preliminary Prospectus, the Pricing Prospectus or the Prospectus, or any amendment or supplement thereto, or any Issuer Free Writing Prospectus in reliance upon and in conformity with the Underwriter Information. (b) Each of the Selling Stockholders will indemnify and hold harmless each Underwriter and each person, if any, who controls any Underwriter within the meaning of Section 15 of the Act or Section 20 of the Exchange Act and their respective officers, directors, employees and selling agents (including any affiliate of an Underwriter involved on behalf of the Underwriter in the distribution process for the Stock) against any losses, claims, damages or liabilities, joint or several, to which such Underwriter may become subject, under the Act or otherwise, in-so-far as such losses, claims, damages or liabilities (or actions in respect thereof) arise out of or are based upon an untrue statement or alleged untrue statement of a material fact contained in the Registration Statement, the Base Prospectus, any Preliminary Prospectus, the Pricing Prospectus or the Prospectus, or any amendment or supplement thereto, or any Issuer Free Writing Prospectus (taken together with the Pricing Disclosure Package), or arise out of or are based upon the omission or alleged omission to state therein a material fact required to be stated therein or necessary to make the statements therein not misleading (in the case of the Preliminary Prospectus, the Pricing Prospectus or the Prospectus, or any amendment or supplement thereto, or any Issuer Free Writing Prospectus, in the light of the circumstances under which they were made), in each case to the extent, but only to the extent, that such untrue statement or alleged untrue statement or omission or alleged omission was made in the Registration Statement, the Base Prospectus, any Preliminary Prospectus, the Pricing Prospectus or the Prospectus, or any amendment or supplement thereto, or any Issuer Free Writing Prospectus, or any such amendment or supplement in reliance upon and in conformity with the Selling Stockholder Information; and will reimburse each Underwriter for any legal or other expenses reasonably incurred by such Underwriter in connection with investigating or defending any such action or claim as such expenses are incurred; provided, however that the Selling Stockholders shall not be liable in any such case to the extent that any such loss, claim, damage or liability arises out of or is based upon an untrue statement or alleged untrue statement or omission or alleged omission made in the Registration Statement, the Base Prospectus, any Preliminary Prospectus, the Pricing Prospectus or the Prospectus or any such amendment or supplement in reliance upon and in conformity with written information furnished to the Company by any Underwriter through the Representatives expressly for use therein, it being understood and agreed that the only such information furnished by any Underwriter consists of the Underwriter Information, provided, further, that the liability of the Selling Stockholders pursuant to this subsection (b) and the indemnity and contribution clauses in Section 9(e) shall not exceed the net proceeds (after deducting underwriting discounts and commissions, but before deducting expenses) received by the Selling Stockholders from the sale of Shares by the Selling Stockholders pursuant to the transactions contemplated hereby (the “Selling Stockholder Proceeds”). (c) Each Underwriter, severally and not jointly, will indemnify and hold harmless the Company, each Selling Stockholder and each person, if any, who controls the Company or any of the Selling Stockholders within the meaning of Section 15 of the Act or Section 20 of the Exchange Act and their respective officers, directors and employees against any losses, claims, damages or liabilities to which the Company or the Selling Stockholders may become subject, under the Act or otherwise, insofar as such losses, claims, damages or liabilities (or actions in respect thereof) arise out of or are based upon an untrue statement or alleged untrue statement of a material fact contained in the Registration Statement, the Base Prospectus, any Preliminary Prospectus, the Pricing Prospectus or the Prospectus, or any amendment or supplement thereto, or any Issuer Free Writing Prospectus, (taken together with the Pricing Disclosure Package), or arise out of or are based upon the omission or alleged omission to state therein a material fact required to be stated therein or necessary to make the statements therein not misleading (in the case of the Preliminary Prospectus, the Pricing Prospectus, the Prospectus, or any amendment or supplement thereto, and any Issuer Free Writing Prospectus, in the light of the circumstances under which they were made), in each case to the extent, but only to the extent, that such untrue statement or alleged untrue statement or omission or alleged omission was made in the Registration Statement, the Base Prospectus, any Preliminary Prospectus, the Pricing Prospectus or the Prospectus, or any amendment or supplement thereto, or any Issuer Free Writing Prospectus, in reliance upon and in conformity with written information furnished to the Company by such Underwriter through the Representatives expressly for use therein; and will reimburse the Company and each Selling Stockholder for any legal or other expenses reasonably 15 US-DOCS\96969269.4

incurred by the Company or the Selling Stockholders in connection with investigating or defending any such action or claim as such expenses are incurred. The Company and the Selling Stockholders each acknowledge that the Underwriter Information constitutes the only information furnished in writing by or on behalf of the Underwriter for inclusion in the Registration Statement, the Base Prospectus, any Preliminary Prospectus, the Pricing Prospectus or the Prospectus, or any amendment or supplement thereto, or any Issuer Free Writing Prospectus. (d) Promptly after receipt by an indemnified party under subsection (a), (b) or (c) of this Section 9 of notice of the commencement of any action, such indemnified party shall, if a claim in respect thereof is to be made against the indemnifying party under such subsection, notify the indemnifying party in writing of the commencement thereof; but the omission so to notify the indemnifying party shall not relieve it from any liability which it may have to any indemnified party otherwise than under subsection (a), (b) or (c) of this Section 9. In case any such action is brought against any indemnified party and it notifies the indemnifying party of the commencement thereof, the indemnifying party shall be entitled to participate therein and, to the extent that it shall wish, jointly with any other indemnifying party similarly notified, to assume the defense thereof, with counsel reasonably satisfactory to such indemnified party (who shall not, except with the consent of the indemnified party, be counsel to the indemnifying party), and, after notice from the indemnifying party to such indemnified party of its election so to assume the defense thereof, the indemnifying party shall not be liable to such indemnified party under such subsection for any legal expenses of other counsel or any other expenses, in each case subsequently incurred by such indemnified party, in connection with the defense thereof other than reasonable costs of investigation. It is understood that the indemnifying party or parties shall not, in connection with any one action or proceeding or separate but substantially similar actions or proceedings arising out of the same general allegations, be liable for the fees and expenses of more than one separate firm of attorneys at any time for all indemnified parties (except to the extent that regular counsel (in addition to any local counsel) is required to effectively defend against any such action or proceeding). No indemnifying party shall, without the written consent of the indemnified party, effect the settlement or compromise of, or consent to the entry of any judgment with respect to, any pending or threatened action or claim in respect of which indemnification or contribution may be sought hereunder (whether or not the indemnified party is an actual or potential party to such action or claim) unless such settlement, compromise or judgment (i) includes an unconditional release of the indemnified party from all liability arising out of such action or claim; and (ii) does not include a statement as to or an admission of fault, culpability or a failure to act, by or on behalf of any indemnified party. (e) If the indemnification provided for in this Section 9 is unavailable to or insufficient to hold harmless an indemnified party under subsection (a), (b) or (c) above in respect of any losses, claims, damages or liabilities (or actions in respect thereof) referred to therein, then each indemnifying party shall contribute to the amount paid or payable by such indemnified party as a result of the losses, claims, damages or liabilities referred to in subsection (a), (b) or (c) above, or actions in respect thereof, in such proportion as is appropriate to reflect the relative benefits received by the Company and the Selling Stockholders on the one hand and the Underwriters on the other from the offering of the Shares. If, however, the allocation provided by the immediately preceding sentence is not permitted by applicable law or if the indemnified party failed to give the notice required under subsection (d) above, then each indemnifying party shall contribute to such amount paid or payable by such indemnified party in such proportion as is appropriate to reflect not only such relative benefits but also the relative fault of the Company and the Selling Stockholders on the one hand and the Underwriters on the other in connection with the statements or omissions which resulted in such losses, claims, damages or liabilities (or actions in respect thereof), as well as any other relevant equitable considerations. The relative benefits received by the Company and Selling Stockholders on the one hand and the Underwriters on the other shall be deemed to be in the same proportion as the total net proceeds from the offering (before deducting expenses) received by the Company and the Selling Stockholders bear to the total underwriting discounts and commissions received by the Underwriters, in each case as set forth in the table on the cover page of the Prospectus. The relative fault shall be determined by reference to, among other things, whether the untrue or alleged untrue statement of a material fact or the omission or alleged omission to state a material fact relates to information supplied by the Company and the Selling Stockholders on the one hand or the Underwriters on the other and the parties’ relative intent, knowledge, access to information and opportunity to correct or prevent such untrue statement or omission. The Company, the Selling Stockholders and the 16 US-DOCS\96969269.4

Underwriters agree that it would not be just and equitable if contribution pursuant to this subsection (e) were determined by pro rata allocation (even if the Underwriters were treated as one entity for such purpose) or by any other method of allocation which does not take account of the equitable considerations referred to above in this subsection (e). The amount paid or payable by an indemnified party as a result of the losses, claims, damages or liabilities (or actions in respect thereof) referred to above in this subsection (e) shall be deemed to include any legal or other expenses reasonably incurred by such indemnified party in connection with investigating or defending any such action or claim. Notwithstanding the provisions of this subsection (e), (i) no Underwriter shall be required to contribute any amount in excess of the amount by which the total price at which the Shares underwritten by it and distributed to the public were offered to the public exceeds the amount of any damages which such Underwriter has otherwise been required to pay by reason of such untrue or alleged untrue statement or omission or alleged omission, and (ii) the contribution by the Selling Stockholders pursuant to this subsection (e) shall not exceed the Selling Stockholder Proceeds (reduced by any amounts the Selling Stockholders is obligated to pay under subsection (b) above). No person guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of the Act) shall be entitled to contribution from any person who was not guilty of such fraudulent misrepresentation. The Underwriters’ obligations in this subsection (e) to contribute are several in proportion to their respective underwriting obligations and not joint. (f) The obligations of the Company and the Selling Stockholders under this Section 9 shall be in addition to any liability which the Company and the Selling Stockholders may otherwise have and shall extend, upon the same terms and conditions, to each officer and director of each Underwriter and each person, if any, who controls any Underwriter within the meaning of the Act and each broker-dealer affiliate of any Underwriter; and the obligations of the Underwriters under this Section 9 shall be in addition to any liability which the respective Underwriters may otherwise have and shall extend, upon the same terms and conditions, to each officer and director of the Company (including any person who, with his or her consent, is named in the Registration Statement as about to become a director of the Company) and to each person, if any, who controls the Company or any Selling Stockholder within the meaning of the Act. 10. (a) If any Underwriter shall default in its obligation to purchase the Shares that it has agreed to purchase hereunder, the Representatives may in their discretion arrange for the Representatives or another party or other parties to purchase such Shares on the terms contained herein. If within thirty-six hours after such default by any Underwriter the Representatives do not arrange for the purchase of such Shares, then the Company and the Selling Stockholders shall be entitled to a further period of thirty-six hours within which to procure another party or other parties reasonably satisfactory to the Representatives to purchase such Shares on such terms. In the event that, within the respective prescribed periods, the Representatives notify the Company and the Selling Stockholders that the Representatives have so arranged for the purchase of such Shares, or the Company or a Selling Stockholder notifies the Representatives that it has so arranged for the purchase of such Shares, the Representatives or the Selling Stockholders shall have the right to postpone the Time of Delivery for a period of not more than seven days, in order to effect whatever changes may thereby be made necessary in the Registration Statement or the Prospectus, or in any other documents or arrangements, and the Company agrees to file promptly any amendments or supplements to the Registration Statement or the Prospectus which in the Representatives’ opinion may thereby be made necessary. The term “Underwriter” as used in this Agreement shall include any person substituted under this Section with like effect as if such person had originally been a party to this Agreement with respect to such Shares. (b) If, after giving effect to any arrangements for the purchase of the Shares of a defaulting Underwriter or Underwriters by the Representatives and the Selling Stockholders as provided in subsection (a) above, the aggregate number of such Shares which remains unpurchased does not exceed one-eleventh of the aggregate number of all the Shares, then the Selling Stockholders shall have the right to require each non-defaulting Underwriter to purchase the number of Shares which such Underwriter agreed to purchase hereunder and, in addition, to require each non-defaulting Underwriter to purchase its pro rata share (based on the number of Shares which such Underwriter agreed to purchase hereunder) of the Shares of such defaulting Underwriter or Underwriters for which such arrangements have not been made; but nothing herein shall relieve a defaulting Underwriter from liability for its default. 17 US-DOCS\96969269.4

(c) If, after giving effect to any arrangements for the purchase of the Shares of a defaulting Underwriter or Underwriters by the Representatives and the Selling Stockholders as provided in subsection (a) above, the aggregate number of such Shares which remains unpurchased exceeds one-eleventh of the aggregate number of all of the Shares, or if the Selling Stockholders shall not exercise the right described in subsection (b) above to require non-defaulting Underwriters to purchase Shares of a defaulting Underwriter or Underwriters, then this Agreement shall thereupon terminate, without liability on the part of any non- defaulting Underwriter, the Company or the Selling Stockholders, except for the expenses to be borne by the Company, the Selling Stockholders and the Underwriters as provided in Section 7 hereof and the indemnity and contribution agreements in Section 9 hereof; but nothing herein shall relieve a defaulting Underwriter from liability for its default. 11. The respective indemnities, agreements, representations, warranties and other statements of the Company, the Selling Stockholders and the several Underwriters, as set forth in this Agreement or made by or on behalf of them, respectively, pursuant to this Agreement, shall remain in full force and effect, regardless of any investigation (or any statement as to the results thereof) made by or on behalf of any Underwriter or any controlling person, officer, director, employees or selling agent of any Underwriter, or the Company, or the Selling Stockholders, or any officer, director, employee or controlling person of either the Company or the Selling Stockholders and shall survive delivery of and payment for the Shares. 12. If this Agreement shall be terminated pursuant to Section 10 hereof, neither the Company nor any of the Selling Stockholders shall then be under any liability to any Underwriter except as provided in Sections 7 and 9 hereof; but, if for any other reason any Shares are not delivered by or on behalf of the Selling Stockholders as provided herein, (x) the Company or (y) if such failure to deliver any Shares arises from the breach of a representation, warranty or covenant by the Selling Stockholders, the Selling Stockholders, will reimburse the Underwriters through the Representatives for all out-of-pocket expenses approved in writing by the Representatives, including fees and disbursements of counsel, reasonably incurred by the Underwriters in making preparations for the purchase, sale and delivery of the Shares not so delivered, but the Company and the Selling Stockholders shall then be under no further liability to any Underwriter except as provided in Sections 7 and 9 hereof. 13. In all dealings hereunder, the Representatives shall act on behalf of each of the Underwriters, and the parties hereto shall be entitled to act and rely upon any statement, request, notice or agreement on behalf of any Underwriter made or given by the Representatives jointly or by Credit Suisse Securities (USA) LLC on behalf of the Representatives; and in all dealings with any Selling Stockholder hereunder, you and the Company shall be entitled to act and rely upon any statement, request, notice or agreement on behalf of such Selling Stockholder made or given by such Selling Stockholder, or in the case of the Selling Stockholders set forth on Part B of Schedule V, the Attorney-in-Fact for such Selling Stockholder. In accordance with the requirements of the USA Patriot Act (Title III of Pub. L. 107-56 (signed into law October 26, 2001)), the Underwriters are required to obtain, verify and record information that identifies their respective clients, including the Company and the Selling Stockholders, which information may include the name and address of their respective clients, as well as other information that will allow the Underwriters to properly identify their respective clients. All statements, requests, notices and agreements hereunder shall be in writing, and if to the Underwriters shall be delivered or sent by mail or facsimile transmission to the Representatives in care of Credit Suisse Securities (USA) LLC, Eleven Xxxxxxx Xxxxxx, Xxx Xxxx, Xxx Xxxx 00000-0000 Facsimile: (212) 325- 4296 Attention: IBCM-Legal; if to the Selling Stockholders shall be delivered or sent by mail or facsimile transmission to the Selling Stockholders at c/x Xxxxxx Corporate Services Limited, P.O. Box 309, Xxxxxx House, South Church Street, Xxxxxx Town, Grand Cayman, KY1-1104, Cayman Islands, fax: (000) 000-0000; if to the Company shall be delivered or sent by mail or facsimile transmission to the address of the Company set forth on the cover of the Registration Statement, Attention: Secretary; and if to any person or entity that has delivered a lock-up letter described in Section 8(l) hereof shall be delivered or sent by mail to his or her respective address provided in writing to the Company. Any such statements, requests, notices or agreements shall take effect upon receipt thereof. 14. This Agreement shall be binding upon, and inure solely to the benefit of, the Underwriters, the Selling Stockholders and the Company and, to the extent provided in Sections 9 and 11 hereof, the officers and directors of the Company and each person who controls the Company, the Selling Stockholders or any Underwriter 18 US-DOCS\96969269.4

and their respective officers, directors, employees, selling agents, heirs, executors, administrators, successors and assigns, and no other person shall acquire or have any right under or by virtue of this Agreement. No purchaser of any of the Shares from any Underwriter shall be deemed a successor or assign by reason merely of such purchase. 15. Time shall be of the essence of this Agreement. As used herein, the term “business day” shall mean any day when the Commission’s office in Washington, D.C. is open for business. 16. Each of the Company and each of the Selling Stockholders acknowledges and agrees that (i) the purchase and sale of the Shares pursuant to this Agreement is an arm’s-length commercial transaction between the Company and the Selling Stockholders, on the one hand, and the several Underwriters, on the other, (ii) in connection therewith and with the process leading to such transaction each Underwriter is acting solely as a principal and not the agent or fiduciary of the Company or the Selling Stockholders, (iii) no Underwriter has assumed an advisory or fiduciary responsibility in favor of the Company or the Selling Stockholders with respect to the offering contemplated hereby or the process leading thereto (irrespective of whether such Underwriter has advised or is currently advising the Company or the Selling Stockholders on other matters) or any other obligation to the Company or the Selling Stockholders except the obligations expressly set forth in this Agreement and (iv) the Company and the Selling Stockholders have consulted their own legal and financial advisors to the extent it deemed appropriate. The Company and the Selling Stockholders agree that they will not claim that the Underwriters, or any of them, has rendered advisory services of any nature or respect, or owes a fiduciary or similar duty to the Company or any of the Selling Stockholders, in connection with such transaction or the process leading thereto. 17. With respect to any Underwriter who is or is affiliated with any person or entity engaged to act as an investment adviser on behalf of a client who has a direct or indirect interest in the Shares being sold by any of the Selling Stockholders, the Shares being sold to such Underwriter shall not include any Shares attributable to such client (with any such shares instead being allocated and sold to the other Underwriters) and, accordingly, the fees or other amounts received by such Underwriter in connection with the transactions contemplated hereby shall not include any fees or other amounts attributable to such client (and, if there is any unsold allotment in the offering at the Time of Delivery, such unsold allotment in respect of Shares attributable to such client shall be allocated solely to Underwriters not affiliated with such client). 18. This Agreement supersedes all prior agreements and understandings (whether written or oral) between the Company, the Selling Stockholders and the Underwriters, or any of them, with respect to the subject matter hereof. 19. This Agreement and any claim, controversy or dispute arising under or related to this Agreement shall be governed by and construed in accordance with the laws of the State of New York. 20. The Company, each of the Selling Stockholder and each of the Underwriters hereby irrevocably waives, to the fullest extent permitted by applicable law, any and all right to trial by jury in any legal proceeding arising out of or relating to this Agreement or the transactions contemplated hereby. 21. This Agreement may be executed by any one or more of the parties hereto in any number of counterparts, each of which shall be deemed to be an original, but all such counterparts shall together constitute one and the same instrument. If the foregoing is in accordance with the Representatives’ understanding, please sign and return to us one for each of the Company, each of the Selling Stockholders and Representatives plus one copy for each counsel, and upon the acceptance hereof by the Representatives, on behalf of each of the Underwriters, this letter and such acceptance hereof shall constitute a binding agreement among each of the Underwriters, the Company and the Selling Stockholders. It is understood that the Representatives’ acceptance of this letter on behalf of each of the Underwriters is pursuant to the authority set forth in a form of Agreement among Underwriters, the form of which shall be submitted to the Company and the Selling Stockholders for examination, upon request, but without warranty on the Representatives’ part as to the authority of the signers thereof. [Remainder of page intentionally left blank] 19 US-DOCS\96969269.4

Very truly yours, Atkore International Group Inc. By: /s/ Xxxxxx X. Xxxxx Name: Xxxxxx X. Xxxxx Title: Vice President, General Counsel and Secretary Signature Page to Underwriting Agreement

CD&R Allied Holdings, L.P. By: CD&R Associates VIII, Ltd., its general partner By: /s/ Xxxxxxx X. Xxxx Name: Xxxxxxx X. Xxxx Title: Vice President, Treasurer and Assistant Secretary Signature Page to Underwriting Agreement

National Philanthropic Trust By: CD&R Allied Holdings, L.P., its attorney-in-fact By: CD&R Associates VIII, Ltd., its general partner By: /s/ Xxxxxxx X. Xxxx Name: Xxxxxxx X. Xxxx Title: Vice President, Treasurer and Assistant Secretary Signature Page to Underwriting Agreement

Fidelity Investments Charitable Gift Fund By: CD&R Allied Holdings, L.P., its attorney-in-fact By: CD&R Associates VIII, Ltd., its general partner By: /s/ Xxxxxxx X. Xxxx Name: Xxxxxxx X. Xxxx Title: Vice President, Treasurer and Assistant Secretary Signature Page to Underwriting Agreement

Accepted as of the date hereof Credit Suisse Securities (USA) LLC By: /s/ Xxxxxxxx Xxxxxxx Name: Xxxxxxxx Xxxxxxx Title: Managing Director Signature Page to Underwriting Agreement

SCHEDULE I Total Number of Shares Underwriter to be Purchased Credit Suisse Securities (USA) LLC ............................................................. 7,234,838 Total 7,234,838 Schedule I US-DOCS\96969269.4

SCHEDULE II (a) Issuer Free Writing Prospectuses not included in the Pricing Disclosure Package None. (b) Additional documents incorporated by reference None. (c) Issuer Free Writing Prospectuses and other information other than the Pricing Prospectus that comprises the Pricing Disclosure Package: The public offering price per share for the Shares is as follows: As to each investor, the price per share for the Shares shall be the price paid by such investor. The number of Shares is 7,234,838. The Time of Delivery is May 21, 2018. Schedule II US-DOCS\96969269.4

SCHEDULE III Directors, Officers, and Stockholders Subject to Lock-Up 1. CD&R Allied Holdings, L.P. 2. Xxxxxx X. Xxxxxxx 3. Xxxx X. Xxxxxxxxxx 4. Xxxxx X. Xxxxxx 5. Xxxxx X. Xxxxxxxxxxx 6. Xxxxxx X. Xxxxx 7. Xxxxx X. Xxxxxxxxx 8. Xxxxxxx X. Xxxxxxx 9. Xxxxxxx X. Xxxxx 10. Xxxx X. Xxxxxx 11. Xxxxx X. Xxxx 12. Xxxxxx X. Xxxxxxx 13. Xxxxxxx XxxXxxxxxx 14. A. Xxxx Xxxxxxx 15. Xxxxxx X. Xxxxxxx 16. Xxxxxxx X. Xxxxxxx 17. Xxxxxxx X. Xxxxx Xx Schedule III US-DOCS\96969269.4

SCHEDULE IV 1. AFC Cable Systems, Inc. 2. Allied Tube & Conduit Corporation 3. Atkore Plastic Pipe Corporation 4. Atkore International Holdings Inc. 5. Atkore International, Inc. Schedule IV US-DOCS\96969269.4

SCHEDULE V Total Number of Firm Shares to be Sold Part A Selling Stockholder CD&R Allied Holdings, L.P. ..................................... 6,960,012 Part B Selling Stockholders National Philanthropic Trust ...................................... 185,237 Fidelity Investments Charitable Gift Fund ................. 89,589 Total 7,234,838 Schedule V US-DOCS\96969269.4

ANNEX III FORM OF LOCK-UP AGREEMENT Credit Suisse Securities (USA) LLC As Representatives of the several Underwriters named in Schedule I to the Underwriting Agreement, c/o Credit Suisse Securities (USA) LLC Eleven Madison Avenue, New York, N.Y. 10010-3629 Re: Atkore International Group Inc. — Public Offering Ladies and Gentlemen: The undersigned understands that you, as representatives (the “Representatives”), propose to enter into an Underwriting Agreement (the “Underwriting Agreement”) on behalf of the several Underwriters named in Schedule I to such agreement (collectively, the “Underwriters”), with Atkore International Group Inc., a Delaware corporation (the “Company”) and CD&R Allied Holdings, L.P. (the “Selling Stockholder”) providing for a public offering (the “Public Offering”) of common stock, $0.01 par value (the “Stock”) of the Company (the “Shares”), pursuant to a Registration Statement on Form S-3 filed with the U.S. Securities and Exchange Commission (the “SEC”). In consideration of the agreement by the Underwriters to offer and sell the Shares, and of other good and valuable consideration the receipt and sufficiency of which is hereby acknowledged, the undersigned agrees that, during the period specified in the following paragraph (the “Lock-Up Period”), the undersigned will not, without the prior written consent of the Representatives, offer, sell, contract to sell, pledge, grant any option to purchase, make any short sale or otherwise dispose of any shares of Stock of the Company, or any options or warrants to purchase any shares of Stock of the Company, or any securities convertible into, exchangeable for or that represent the right to receive shares of Stock of the Company, whether now owned or hereinafter acquired, owned directly by the undersigned (including holding as a custodian) or with respect to which the undersigned has beneficial ownership within the rules and regulations of the SEC (collectively the “Undersigned’s Shares”) (other than the sale of any shares of Stock acquired after the Public Offering that is not required to be reported in any public report or filing with the SEC and regarding which the undersigned does not otherwise voluntarily effect any public filing or report). The foregoing restriction is expressly agreed to preclude the undersigned from engaging in any hedging or other transaction which is designed to or which reasonably could be expected to lead to or result in a sale or disposition of the Undersigned’s Shares even if such Shares would be disposed of by someone other than the undersigned. Such prohibited hedging or other transactions would include without limitation any short sale or any purchase, sale or grant of any right (including without limitation any put or call option) with respect to any of the Undersigned’s Shares or with respect to any security that includes, relates to, or derives any significant part of its value from such Shares. The Lock-Up Period will commence on the date of the preliminary prospectus used at the commencement of the roadshow in connection with the offering of Shares and continue for 30 days after the public offering date set forth on the final prospectus (the “Public Offering Date”) pursuant to the Underwriting Agreement. Notwithstanding the foregoing, (A) the undersigned may transfer the Undersigned’s Shares without the prior written consent of the Representatives pursuant to any trading plan in effect prior to the date hereof intended to comply with Rule 10b5-1 under the Securities Exchange Act of 1934, as amended (the “1934 Act”); provided that any Form 4 reported in accordance with Section 16 of the Securities Exchange Act of 1934 shall denote in a footnote that the transfer was pursuant to an established Rule 10b5-1 plan, and (B) subject to the conditions below, the undersigned may transfer the Undersigned’s Shares without the prior written consent of the Representatives on behalf of the Underwriters: (i) to the Underwriters pursuant to the Underwriting Agreement; Annex III US-DOCS\96969269.4

(ii) pursuant to a bona fide third-party tender offer, merger, consolidation or other similar transaction made to all holders of the Stock involving a Change of Control (as defined below) of the Company, provided that in the event that the tender offer, merger, consolidation or other such transaction is abandoned, the Undersigned’s Shares shall remain subject to the restrictions hereunder; or (iii) as a bona fide gift or gifts; or (iv) by will or intestacy; or (v) to any trust for the direct or indirect benefit of the undersigned or the immediate family of the undersigned (for purposes of this Lock-Up Agreement, “immediate family” shall mean any relationship by blood, marriage or adoption, not more remote than first cousin); or (vi) as a distribution to partners, members or stockholders of the undersigned; or (vii) to the undersigned’s subsidiaries, affiliates or to any investment fund or other entity controlled or managed by, or under common control or management with, the undersigned; or (viii) disposition of shares of Stock to the Company or the retention of shares of Stock by the Company to (i) satisfy tax withholding obligations in connection with the exercise of options to purchase Stock, the vesting of restricted stock units or the settlement of deferred stock units or (ii) in payment of the exercise or purchase price with respect to the exercise of options to purchase Stock, the vesting of restricted stock units or the settlement of deferred stock units; (ix) as transfers of shares of Stock by the undersigned in connection with bona fide gifts of such shares of Stock to charitable organizations by certain partners and employees of the undersigned, its affiliates or any investment fund or other entity controlled or managed by, or under common control or management with, the undersigned; or (x) transfers of shares of Stock by CD&R Allied Holdings, L.P. on or prior to the date of the Prospectus by bona fide gift to any charitable organizations, either directly or indirectly (including through any related distributions or dividends to the direct or indirect equity holders of CD&R Allied Holdings, L.P. or to investment professionals of Xxxxxxx, Dubilier & Rice, LLC, in each case as necessary to facilitate any such bona fide gifts); provided, however, that (1) in the case of clauses (iii)-(vii) and (ix) above, the Representatives shall have received a signed lock-up agreement for the balance of the Lock-Up Period from each donee, trustee, distributee, or transferee, as the case may be, prior to such transfer; (2) such transfers (other than those described above in (i), (ii), (v) and (viii)) shall not involve a disposition for value; (3) such transfers (other than those described above in (i), (ii), (viii) and (ix) and transfers described in (vi) that are effected to enable the transfer described in (ix)) are not required to be reported with the SEC on Form 4 in accordance with Section 16 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”); and (4) the undersigned does not otherwise voluntarily effect any public filing or report regarding a transfer made pursuant to clauses (i) to (ix) above. For purposes of clause (ii) above, “Change of Control” shall mean the consummation of any bona fide third party tender offer, merger, consolidation or other similar transaction the result of which is that any “person” (as defined in Section 13(d)(3) of the Exchange Act), or group of persons, becomes the beneficial owner (as defined in Rules 13d-3 and 13d-5 of the Exchange Act) of a majority of total voting power of the voting stock of the Company. Nothing in this agreement shall prevent the establishment of a trading plan pursuant to Rule 10b5-1 under the Exchange Act for the transfer of shares of Stock, provided that such plan (1) does not provide for the transfer of Stock during the Lock-up Period, and (2) is not required to be reported and is not voluntarily reported in any public report or filing with the SEC during the first 30 days following the Public Offering Date. The undersigned also agrees and consents to the entry of stop transfer instructions with the Company’s transfer agent and registrar against the transfer of the Undersigned’s Shares except in compliance with the foregoing restrictions. Annex III US-DOCS\96969269.4

The undersigned understands that the Company and the Underwriters are relying upon this Lock-Up Agreement in proceeding toward consummation of the offering. The undersigned further understands that this Lock- Up Agreement is irrevocable and shall be binding upon the undersigned’s heirs, legal representatives, successors, and assigns. This agreement and any claim, controversy or dispute arising under or related to this agreement shall be governed by and construed in accordance with the laws of the State of New York. Very truly yours, Exact Name of Shareholder Authorized Signature Title Annex III US-DOCS\96969269.4