Common use of Form Work Clause in Contracts

Form Work. Formworks for concrete shall be constructed from materials of sufficient strength and supported to ensure that there is no deflection when concrete in placed. The formwork shall conform to the shapes, lines and dimensions of structures shown on the drawings. Where the concrete finished surface is exposed, the formwork shall be of good quality and free of gaps. Formwork shall not be removed until the concrete has obtained sufficient strength. Normally, formwork can be removed from walls after 2 days and from beneath slabs after 2 weeks. The minimum periods between concreting and the removal of forms shall be as follows: Sides of beams, walls, columns and piles 24 hours Soffits of secondary slabs (props left in) 4 days Soffits of main slabs (props left in) 8 days Soffits of beams (props left in) 8 days Removal of props - secondary slabs 10 days Removal of props - beams and main slabs 21 days Arch centres, wedges eased 8 days Arch centres, struck 21 days The times in the above table are given as a guide and are based on average weather conditions and the use of Ordinary Cement. They may be changed if other types of cement are used, subject to the Engineer's agreement. Formwork shall be constructed so that it can be removed without undue shock or vibration and so that side shutters of members can be removed without disturbing the soffit shutters; if the contractor wishes to leave some of the props in place when the soffit shutters are removed, these props shall not be disturbed during the striking. The detailed arrangements of the props shall be submitted in advance to the Engineer. In the case of heavy loading, folding wedges shall be provided. For pre-stressed units the side shutters shall be eased as early as possible and the soffit shutters shall permit movement of the units when the pre-stress is applied. All formwork must be removed without damage to the concrete.