I have got a couple of leakages in the PVC drainpipes which convey the rain water from my flat roof.

The pipes are not accesible since they are behind tile walls.

Is there any sealing liquid I can pour in the entry to the drainpipe in the roof so that it seals the leakage?

The leakage is not too big but when there is heavy rain some damp stains appear in some parts of the ceiling.

I know that there are some liquids intended for solving this problem in swimming pools but as in this case the pipe is not "full" of water they might not work in this case.

I hope you can help me.

Best regards,

Harri

I have got a couple of leakages in the PVC drainpipes which convey the rain water from my flat roof.

The pipes are not accesible since they are behind tile walls.

Is there any sealing liquid I can pour in the entry to the drainpipe in the roof so that it seals the leakage?

The leakage is not too big but when there is heavy rain some damp stains appear in some parts of the ceiling.

I know that there are some liquids intended for solving this problem in swimming pools but as in this case the pipe is not "full" of water they might not work in this case.
I hope you can help me.

Best regards,

Harri
Hi Harri,
The leaks are not "unaccessible". You can always open up the tile walls. But I question whether the leak is coming from a glued joint inside the walls. Once PVC pipes are glued properly the PVC is welded together. It's unlikely that such a weld would open up and leak. I would check out the connections on the drain that's on the roof first. I know of no "miracle stop leak product" that is selective in locating and repairing a internal leak in drainage systems. Regards, Tom

Before I tore up the tile wall, I would try dabbing some tar around on the roof. As Tom said, PVC joints seldom go bad, but roof flashing frequently does. I hope you can find a day to work on the roof before the wall is damaged. Early in my home ownership, I had rain leak through the flashing, run down the outside of the vent pipe and ruin the plywood sub floor, damaging the floor tile. I was forever replacing the 1'' tiles.

One more thing, you could try dumping water down the drain pipe and see if it leaks. If it doesn't, the leak is elsewhere. If it does, you may have to tear into the wall.