This copper pipe goes in between 2 roof tiles (cement/hard tiles). Water constantly leaks through when it rains. The water clings to the pipe and then drips onto the ceiling.
As you can see from the images, multiple people have tried to plug this leak, including me. I used a product called Sikaflex 11FC sealant.
In this image, you'll notice that I've scraped away the sealant close to the pipe. When I did this, I noticed that it was all gummy, which makes me think that it never hardened properly.
The gap that you see is the gap between the 2 tiles. It's bigger than other gaps on the roof because of the pipe. I've also tried to plug this gap all the way and the sealant was much harder further away from the pipe, which makes me conclude that the weak point is close to the pipe itself.
Is this just a very bad installation that can't be saved, or is there something I can do to waterproof it properly?
Best Answer
I would take a piece of flexible rubber sheeting approximately 12"X12", cut a hole in the rubber about the size of the tubing (make it a tight fit), near the center, and slit the rubber from the edge to the cut hole. Fit the rubber sheet around the tubing and use silicone caulking to seal the underside of the rubber, the slit area and between the tubing and rubber sheet. Use a lot of a good silicone caulk (not the cheap stuff or spray foam), 2-3 Tubes of caulking should suffice. Lastly, coat the whole top of the rubber sheet with a thick film of caulking and spread with a cheap paint brush to coat the whole rubber sheet out past the edges.