How can I waterproof seams in plastic wavy roofing?

I use silicon caulking...works perfectly

Use a clear silicone to waterproof the seams . Good luck !

Bonnie,

Your seams probably overlap one peak and valley They are probably secured with special screws that have a rubber washer so they don't leak and are screwed into the ceiling joists and/or battens depending on how it's framed. How is the overlap sealed now or are the panel overlaps not sealed? Some panel roofs rely on the screws going through the overlap to make it watertight. Clear silicone or a silicone blend caulking is sometimes used to seal the overlaps. You could also have a crack in a panel that is hard to see or a crack where the screws are. If you can, run your hose over each panel and seam to see exactly where it is leaking. You can also gently lift up on each overlapping seam between screws to see if it separates. If so, remove any old caulking, clean the area you are going to caulk, and lay a thick bead of new caulking down the length of the seam and then press the seam together to make sure you get good contact between both panels and the caulking. Be careful while on top of the roof structure and keep your weight on the framing, not on a panel. You can lay a board or small piece of plywood that spans a few joists to kneel on. Also, how do the panels meet the side(s) of the house? There should be some type of flashing there to prevent water from leaking in between the roof panel and the siding that you can check as well.

We have the same issue. Nothing has worked.

Hi Bonnie, hope this link helps you repair it

https://www.ehow.com/how_7387985_repair-leaks-plastic-corrugated-roofing.html