The membrane is screwed down every five feet using screws and plates. The plates act like a washer helping to hold the membrane over a larger surface area. The screws and plates are usually placed 12” on center. The next sheet of PVC is then layered over top of the line of fasteners and usually over laps the line of screws and plates by 6”. Then, the two sheets are hot air welded together which forms a permeant water tight seam The over lap covers the screws and this is how you can screw down a membrane without poking holes in it that leak.
1. How can you screw down the PVC membrane without poking holes in it that leak?
