Newer sealant on new sealant. - TilersForums.com

[mattyg]

Hiya guys

New wetroom has a small leak. Its taken 3 months to show but I think I've traced it to a small section of sealant around the floor/wall edge that has dragged when tooled and another small section down the edge of a tile.

At least I hope it is.

Anyhow. Do I have to remove ALL of the sealant before redoing?
I'm sure I've read that new sealant wont bond to old sealant. If so how far do I need to go. All around the room and up the wall????

Edit: Old/new sealant is Mapei Mapersil AC

Cheers
Matt

 

[Dan]

Wasn't it tanked before being tiled? It shouldn't matter if the sealant 'has failed' because it isn't really there to create a water tight job. It should be tanked, then tiled, then the sealant is just there on internal corners to deal with flex and expansion etc, grout would crack and look poor quality if it did.

It might be the case that it was just being used a bit longer than normal, and actually, it's leaking after most uses, but disperses after short bursts of use.

If that's the case, it's probably causing damage behind the tiling even when it's not showing through elsewhere.

If you think more sealant is the way to go, strip to the corner or whatever and then reseal the whole run. Don't go over it as is.

But if you can show us some photo's we might be able to help investigate a bit more.

What was it tiled with?
Was it tanked? If so, what with?