What is the best way to form circular openings for pipes to pass through floors and how do you anchor such form materials so they stay in place and remain vertical?
One method is to use fiber sleeves with metal cups and caps. A metal cup is nailed to the formwork of an above-grade floor or anchored with a spike to the subgrade of a slab on grade. A fiber tube or sleeve fits over this cup snugly so that it stays in place. A thin metal cap covers the top of the tube to prevent concrete from entering it. Plastic sleeve systems also are available.