another waterproofing question

[piper64]

Hi all

Having boarded out the shower area with Delta Boards, I'm now puzzled at the the next step. I was told by the supplier, Tileflair, that I only need to silicone the joints and corners, then tile.

The cement delta boards are only water-resistant/waterproof, the cement based Magix-S tile adhesive is only water-resistant, so simply siliconing the joins doesn't seem good enough. I have siliconed between each board as I've put them on the wall, like cement between bricks.

I bought some alkali resistant tape and intended to use that with a buttering of tile adhesive on it to make the 'seal' over any joins and in the vertical corners.

I've spoken to Tilemaster Adhesives and they assure me that I don't need to do that unless I want to. They explained that as cement based products allow some degree of water through, the application of silicone at the joints is sensible as a way of preventing any moisture getting where it shouldn't.

Silicone will, at some point, break down I fear so what then?

I would like to apply tanking down the joints and along the board joints, but all I can see if expensive kits that have ore than I need in them. I just need waterproof tape I'm guessing?

Then, when the tray is in place, I want to seal that too. Reading this forum, there is much conflicting advice as to what is best...some say butyl tape, some say Mapei tape ( again, part of a kit that I dont really want to buy just for soem tape).

Any pointers would be appreciated, so I can get on with tiling.

 

[27neth]

https://www.tilefixdirect.com/product/OBSEALK

For the tray

John

 

[27neth]

The joints https://www.tilefixdirect.com/product/MXWPS

John..

 

[piper64]

Thank for that. I need 15m of tape to do the joins and vertical corners, so at 10m I'm going to need to get two of the tapes. It comes out expensive at £65 or so.

Too add more confusion, I bumped into a Wedi rep ( same thing as Deltaboards) at a trade show in Topps tiles yesterday and he said that I only need to apply Wedi610 ( a waterproof adhesive and sealant) to the joins and corners, then put scrim over the top for strength. He even gave me a tube of 610, which was very good of him as it would have cost me £20 to buy. Now I'm more confused. Does this 'wonder sealant' do it all or do I go to the expense of tape and membrane?

Then I got to thinking about all the holes I've put in the waterproof board in order to apply the mechanical fixings. Surely I've breached the waterproof properties? Looked at the Wedi tech sheets and no mention of this being a problem. If so, how is the 'possible' transfer of moisture via any unsealed joins any different?

 

[27neth]

There’s other kits on the market for the tape. Every type of board I have looked at you need to tape the joints and fixings with a water proof tape. Wedi seems to be the only one where it says you can use the sealant only,but it also says you can use the tape instead.
They all seem to say use the scrim tape in areas that won’t get wet.
I have got sheets of the Kerdi board waiting for me to fix to my bathroom walls, I have there tape and tape adhesive which I’m using on all the joints and fixings holes.

John..

 

[piper64]

I ordered 5kg MapeiWPS and 25m of carrier material from PureAdhesion, that should do the verticals and joints with some to daub over the fixings too. I don't want to spread too much 610 around as tile adhesive won't stick to it. Then again, does it stick to any waterproofing gum?

 

[jonb1985]

Hi piper, I'm in the same position as you, just bought the deltaboards from tileflair, seemed like a good idea given that the board themselves are waterproof, but now unsure what I'm supposed to do about the joints, they said I could use regular silicone sealant or offered me some butyl tape but said that would need tanking over too. Not really sure what I should do. What did you decide upon in the end and how did it go?

Thanks

 

[piper64]

Hi, I bought tape and tanking solution to cover each join. Mapeigum WPS and Mira SafeCoat Fibre strip. I got it online from PureAdhesion, very knowledgeable chap there.