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?