When constructing a floor, concrete contractors often unroll a sheet of plastic vapor retarder over the subbase and cover it with a blotter layer of compacted granular fill before placing concrete on the fill. But how effectively do vapor retarders resist punctures during construction operations?
In bidding a job, concrete contractors have to estimate the duration of each concrete placement, which requires estimating the concrete's setting time. When cold weather, admixtures, or other factors delay setting and increase the time finishers must wait, the contractor starts losing money. But how much money?