Another Tanking Question

[Richie1984]

Got a quick question about tanking.

Ive got the Dunlop tanking kit and its instructions are to overlap slightly the shower tray (or in my case the bath) with the tape. Now my question is if you were then to apply tiles over this waterproof membrane and run silicone along the join between the bath and the tiles wont any water that does penetrate the grout be "stuck" between the waterproof membrane and the silicone, almost acting like a trough behind the tiles?

Thanks for any responses, seems like a good forum by the way, had a lot of useful advice since signing up a few days ago.

 

[lancenotalot]

I would never use tape on a bath/shower tray join.
Silicon before tiling then tile and grout,then silicon again,I would only tape around the base if it were a wet room with tiled floor and even then I would silicon the corners after.

Dont forget to fill teh bath with water before you silicon and leave it till cured

 

[Richie1984]

The problem I have is basically the plasterboard comes down to the top edge of the bath (overlapping the bath) and then stops and underneath the bath there is no plasterboard underneath the bath, basically just the studs, old laths, a little bit of old plaster and some ancient insulation. If I only tanked to where the plasterboard ends (2mm above the bath) then filled the gap with silicone, tiled, grouted then siliconed again then would I not still have this problem of the water having no where to "escape to"? Maybe im just being dumb I dont know, but I dont want my wall turning into some sort of water trap!

Does the water escape back through the grout which has presumably let it in??

 

[lancenotalot]

Ah ok,not as cut and dried as I first though,ideally it would be best to board down behind the bath and tank it but if this is not an option then I would
1.grip fill the gap around the bath,use a plastic square edge to push it into the gap under the plasterboard.

2.mask the edge of the bath leaving a small gap that would be covered by the tiles.

3.tank the walls and on the the edge of the masking tape then peel off the tape.

4.silicon

5.tile and grout

6.silicon again

See what some of the others suggest as they may have a better idea but I really would consider boarding and tanking a few cm behind the bath for best results.

 

[Richie1984]

Ok that sounds pretty good.

This problem all arose from me not doing my homework the first time round (and also missing out and O-ring when reassembling the shower ) and basically I had to rip down the work I had already done. When I took it down I pulled all the old lath and plaster off and strapped the wall and used plasterboard but in doing this it brought the wall out so that it overlapped the bath (which I couldnt move). Presumably this grip fill is not hard to come by?

 

[gcol]

Only thing I can add to Lance's advice is that silicone ends in an "e".
Good advice.

 

[Richie1984]

Just to clarify, the gripfill is there for the tanking to stick to as presumably it doesnt stick to silicone?

The chemical element isnt spelled with and e, though I suspect putting raw silicon on a bath would not only be very expensive but pretty much as useful as t!ts on a fish!

 

[lancenotalot]

Only thing I can add to Lance's advice is that silicone ends in an "e".
Good advice.

Tank u 4 cowecting my engwish mr Collier

Yes grip fill as tanking fluid won't stick to siliconE

 

[gcol]

Just to clarify, the gripfill is there for the tanking to stick to as presumably it doesnt stick to silicone?

The gripfill (or equivalent) is there to hold your sh*t together.

The chemical element isnt spelled with and e, though I suspect putting raw silicon on a bath would not only be very expensive but pretty much as useful as t!ts on a fish!