Prevent leaks from wetroom?

[sendu]

I’m planning on an extension which will be a wet room above an existing dining room (so adding a second story).

I want this kind of seamless walk-in effect for the shower:

 

But what do I need to specify in order to avoid leaks to the dining room below?

 

With a normal enclosed shower I’d specify a shower tray with a tile-over lip so that if the grout or silicon seal failed, water would still not escape to the room below. But I don’t know anything about wet rooms.

 

What sort of construction method or products should be used to best avoid leaks?

[Onoff]

Whatever wall and floor substrate you use has to be "tanked". That is a waterproof liquid tanking membrane applied in two or more coats with flexible reinforcing tape at the wall/floor junctions, corners etc. 

 

This will give you an idea:

 

 

You also need to pay careful attention to your drain detail.

 

@AnonymousBosch on here is just starting his.

[ProDave]

You waterproof the whole floor in a process called tanking, that can either be a membrane or a paint on system.  You use a ready made shower former (or you can make one) so that the floor in the shower area slopes down to the drain.  Then you tile it.

 

Even if the grout cracked, the floor is waterproof even before the tiles go down.

[Onoff]

 

Or there's my epic thread if you've nothing better to do. If you can stick with it I do end up with a tanked wet room corner with tiled sloping floor, cast to falls and a Geberit wall drain! ?

 

 

 

Edited January 14, 2020 by Onoff

[nod]

  On 14/01/2020 at 09:35, ProDave said:

You waterproof the whole floor in a process called tanking, that can either be a membrane or a paint on system.  You use a ready made shower former (or you can make one) so that the floor in the shower area slopes down to the drain.  Then you tile it.

 

Even if the grout cracked, the floor is waterproof even before the tiles go down.

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Plus one there 

Never rely on the tiles to keep the water in 

[Onoff]

"A true Wetroom install should be OK to use WITHOUT EVER TILING IT, remember that and you’ll be fine. ?"

 

Said @Nickfromwales 07 Jan 2020

[sendu]

Thanks all.

 

On a related topic, there will also be a free-standing bath in the room. I see the advice about a sloping floor to the drain in the shower area, but how do you avoid pooling around the bath?

 

Do people just not concern themselves with this, maybe just put down an absorbent matt at most?

 

 

It will with a spa-bath that can only be repaired by lifting the whole bath off the ground. How would you stop water getting under the bath during use, assuming you wouldn't want to glue/tape it down to the tiles? Just put a rubber strip along the bottom edge and let the weight of the bath create a compression seal? Is that something any plumber could figure out how to attach and make work?

[Onoff]

  On 14/01/2020 at 13:05, sendu said:

but how do you avoid pooling around the bath?

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Kick the towel around the floor is what we do when finished showering then straight in for washing. UFH helps dry the floor quicker as does good extract. 

[Onoff]

My spa bath is part sunken (so the floor of the bath is level with the adjacent tiled floor). Access panels in the side covered by tiles give access to the trap etc. If worst case happens I can break two tiles, take the silicone off and lift half the bath surround away.

 

 

Edited January 14, 2020 by Onoff

[ToughButterCup]

  On 14/01/2020 at 13:19, Onoff said:

If the worst case happens I can break two tiles, take the silicone off and lift half the bath surround away.

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Smash + grab?

[Nickfromwales]

  On 14/01/2020 at 13:36, AnonymousBosch said:

Smash + grab?

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He does come from a rough area.....?

[Onoff]

The bath end panel has tiles stuck on 12mm marine ply with CT1 Grab & Bond. The "grout" is in fact Everbuild Forever white. That covers the screw holes also. Easy to cut out. You can see the join at the two halves of the bath frame:

 

 

Similar trap access from the side: