Discuss Advice needed on tanking wall-to-ceiling and wall-to-shower tray joints in the Tanking and Wetrooms Forum area at TilersForums.com

schismatic

New to TilersForums.com
Planning to tank my en-suite tomorrow, using the BAL WP1 waterproofing kit. The ceiling is existing painted plasterboard. Do I need to tape and treat the joints between wall and ceiling like I do for the corners?

My gut says no, as the WP1 can't be painted on etc after. Presumably if I don't tank them, then I can just finish with sealant to match the paint? I know some just caulk too.

Just checking I'm not making a daft decision!

Also, where the bottom of the wall meets the shower tray, do I waterproof that joint? I'm assuming if I do that half of the tape will overlap down onto the shower tray for the time being, with WP1 just being applied to the walls and not the tray itself. Then presumably I just cut the tape away after tiling?? Some advice on how you go about waterproofing that joint would be much appreciate!
 

Localtiler

Trusted Advisor
Professional Tiler
JOTM Winner
Your right about the ceiling, as long as you tank to the shower head that's enough. Sealing to the tray is a debatable thiing, some do exactly as you have said as I do myself when I need to, but I prefer tanking before the tray goes in when possible or even if the tray is in but not siliconed I will tape the tray up and tank below the tray Line give it a good deal with silicone after .
 
W

Waluigi

Unregistered (Please Register)
Personally I don’t tape the wall to tray joint. I’ll tank and then silicone on top of the tanking

If you can, tank the wall first you then bond the tray to the tanked wall with clear silicone. Clear sticks better than white or coloured.
 
OP
S

schismatic

New to TilersForums.com
Thanks for the suggestions all, amazingly useful as usual. I’ve already sealed between bottom of the wall and the tray itself, so will have to tank over that. Planning to use masking tape to assist with how far onto the tray I go as suggested.
 
W

Waluigi

Unregistered (Please Register)
Bal might’ve changed the formula since I last used it but I specifically remember them saying that their tanking won’t stick to silicone. This is going back many years though.
 
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schismatic

New to TilersForums.com
Hmm, I’ve got a dilemma then. I’ve alresdy siliconed between the tray and the bottom of the wall. Do you suggest I remove this silicone and replace with something else than I *can* tank (caulk??), or should I just apply the tanking to the wall only for now and rely on the silicone underneath as a water barrier (note that this will be behind tiles and a further line of sealant between bottom of tiles and the tray).
 

widler

Professional Tiler
I’d just tank down to the tray , not a fan of rapping the tape over the tray , I can peel any spilled tanking off a tray with ease , so imo sticking the tape on the tray is a weaker joint than silicone ,silicone is harder to peel off , tanking is made to protect the substrate in a shower area, whereas in a wet room it’s to stop leaks .
I’m sure some will disagree with me ;)
(That’s when I tank ;) )
 
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