Tanking a shower area against tray

[phatboy]

Hi all,

I am fitting a shower tray soon, and will tank the Wedi boarded walls. What's the usual way to seal the tanking to the tray? Do I paint to the edge and over by a few mm, to be covered with the tiles. Or do I use some of these online kits I've seen, that stick to the wall and have a sort of rubber seal on the bottom?

My tanking kit just has primer, tape, and the waterproof liquid.

Thank you!

 

[23vc]

I normally mask off the tray leaving about the last 8mm exposed which the tiling and silicone bead will cover.

 

[phatboy]

I normally mask off the tray leaving about the last 8mm exposed which the tiling and silicone bead will cover.

Thanks, thats what I thought seemed reasonable.

 

[noseall]

Hi all,

I am fitting a shower tray soon, and will tank the Wedi boarded walls. What's the usual way to seal the tanking to the tray? Do I paint to the edge and over by a few mm, to be covered with the tiles. Or do I use some of these online kits I've seen, that stick to the wall and have a sort of rubber seal on the bottom?

My tanking kit just has primer, tape, and the waterproof liquid.

Thank you!

We tank, then fit the tray after, pushed up against a bead or two of sealant.

 

[23vc]

We tank, then fit the tray after, pushed up against a bead or two of sealant.

I’ve gotta do one soon, and I reckon I’ll do it this way rather than how I’ve always done it (masked tray and tanked a few mm onto it). Is this a fairly common thing? Never seen anyone do it but it makes sense to me and can’t see any downsides, and it’s easier

 

[Ivor Windybottom]

I sealed the tray to the wall, wiped off flush with the top of the tray, then used the tanking kit rubber tape to seal onto the top of the tray. Then tiled, then sealant again. It won't leak.

Mine's on concrete that's sitting on the foundation (ground floor), so will never move. You may need to do things less rigidly to allow movement if it's on a suspended floor.

 

[23vc]

Yeah, that’s what I’ve always done. I’m always keen to make life easier though, and am tempted by @noseall method above. Saves the faff of masking the tray etc.

 

[phatboy]

I still havent done this job... may be swayed.....

I though the objective was that if water got behind the tiles, it should re-appear in the tray and not below it? Silicone has a habit of shrinking or otherwise failing over time?

 

[23vc]

I’m going on the assumption that the solid silicone layer between tray side and wall is permanent and impermeable. I can’t recall ever seeing silicone under compression disintegrate much, but yeah if it did it’d be an issue.

 

[yorksbuilder]

It's about eliminating the likelihood of leaks. If you follow the instructions on the tanking kit they will tell you to stick the tape onto the edge of the tray. If you don't follow this then you have no come back on them.

Water will follow the path of least resistance. If there happens to be any problem with the silicone around the edge, or human error means a gap is left, it will leak

With shower trays, I go for the belt and braces approach, and ensure the tanking itself directs any water back into the tray IF it gets past the tiles, grout, adhesive and silicone seal!

 

[noseall]

Use polymer sealant not silicone.

 

[yorksbuilder]

Stixall is your friend for the beads between the tray and the wall

 

[23vc]

Cool, I’m very tempted to do this then:
Offer tray up, check it’ll sit level on some rapidset or silicone or whatever the instructions say
Tank walls, all the way down to floor, only use tape on wall corner
When tanking dry, thick beads of stixall on walls and tray pushed tight to them and bedded down

I get what you’re saying about no comebacks on tanking manufacturer but probably acceptable risk in my case.

 

[noseall]

Cool, I’m very tempted to do this then:
Offer tray up, check it’ll sit level on some rapidset or silicone or whatever the instructions say
Tank walls, all the way down to floor, only use tape on wall corner
When tanking dry, thick beads of stixall on walls and tray pushed tight to them and bedded down

I get what you’re saying about no comebacks on tanking manufacturer but probably acceptable risk in my case.

There’s nothing stopping you adding the sticky tape after.

 

[Ollyfp]

I'm bedding a shower tray down this week. The manufacturers recommend bedding down on blobs of mortar, but I removed a tray a few years back and the cement blobs beneath it had dried and crumbled away leaving areas of the tray unsupported.
Can anyone suggest an alternative?
Thanking you kindly!