Tanking Floor - Tile Advice

[Skylad]

Hi
I’m having a wetroom refurbishment.
Tough-x Wetroom former fitted its self supporting GRP.
Anyway fitter is putting wedi boards on the walls and is going to tank them, I asked if he was tanking the tray as well to which he replied it doesn’t need it because it’s waterproof.
I think it’s risky and he’s got the tanking so put some on before tiling.
Should I insist?
Thanks.

 

[Steve6690]

I thought wedi board was waterproof and therefore does not require tanking?

 

[Wetroom specialist]

Hi
I’m having a wetroom refurbishment.
Tough-x Wetroom former fitted its self supporting GRP.
Anyway fitter is putting wedi boards on the walls and is going to tank them, I asked if he was tanking the tray as well to which he replied it doesn’t need it because it’s waterproof.
I think it’s risky and he’s got the tanking so put some on before tiling.
Should I insist?
Thanks.

Hi Skylad. YES! There are two things I ignore.
1. Always, always underboard no matter how good they tell you a system is. Any system. Why take the risk for the cost of some 18mm ply and a couple of hours extra work?. Tiles and particularly grout do not like movement. All you need is a hairline crack. Even if it didn't leak you could get water ingress under the tiles...not good.
2. Always, always tank it. Even if they say it doesn't need it. How are you going to waterproof the wall and floor junction without properly tanking it? Let alone the waste! Let alone where the former meets the floor!! Please don't let anyone tell you Silicone. It will eventually break down. It might not be this year or even next. But it will break down. Proper tanking doesn't.
Hope this is in time and doesn't scare you too much.

 

[Skylad]

Hi Skylad. YES! There are two things I ignore.
1. Always, always underboard no matter how good they tell you a system is. Any system. Why take the risk for the cost of some 18mm ply and a couple of hours extra work?. Tiles and particularly grout do not like movement. All you need is a hairline crack. Even if it didn't leak you could get water ingress under the tiles...not good.
2. Always, always tank it. Even if they say it doesn't need it. How are you going to waterproof the wall and floor junction without properly tanking it? Let alone the waste! Let alone where the former meets the floor!! Please don't let anyone tell you Silicone. It will eventually break down. It might not be this year or even next. But it will break down. Proper tanking doesn't.
Hope this is in time and doesn't scare you too much.

Thanks for the reply, I ended up tanking it with mapei liquid membrane myself as the bathroom fitter said he didn’t have the right tile cutter to do the wet room floor ( nightmare left me in a right mess, made every excuse under the sun not to come back ) Just managed to get a decent tiler up today who has just laid the tiles easily enough with a wet cutter and will grout tomorrow.
Hopefully everything will be ok 👍

 

[Steve6690]

Hi Skylad. YES! There are two things I ignore.
1. Always, always underboard no matter how good they tell you a system is. Any system. Why take the risk for the cost of some 18mm ply and a couple of hours extra work?. Tiles and particularly grout do not like movement. All you need is a hairline crack. Even if it didn't leak you could get water ingress under the tiles...not good.
2. Always, always tank it. Even if they say it doesn't need it. How are you going to waterproof the wall and floor junction without properly tanking it? Let alone the waste! Let alone where the former meets the floor!! Please don't let anyone tell you Silicone. It will eventually break down. It might not be this year or even next. But it will break down. Proper tanking doesn't.
Hope this is in time and doesn't scare you too much.

So you'd recommend WEDI board to be overpainted with a liquid membrane tanking system?