What precautions should be taken when using polyethylene film in curing flatwork?
The main idea is to see that it stays on the slab and doesn't have or develop any leaks. The sheet should be effectively weighted at all edges and lapped areas so that it doesn't get whipped off by wind or dislocated by workmen. It should be placed as soon as the concrete is hard enough to withstand marring of the surface. There should be four to six inches of overlap and these areas should be sealed with pressure-sensitive tapes or nonstaining mastics. Weighting with planks for the full length of the overlap may be adequate. Joints can also be sealed by portable electric joint sealing tools but this is seldom done.