Rushed shower preparation.....now what?

[focaltucker]

I think I’ve messed up (rushed) my preparation and I now don’t know whether to carry on or go back and start again doing things differently.

I’m having a shuffle around to fit a shower into the bathroom. I removed the old tiles and most of the plaster skin came off, leaving mainly bare plasterboard, one stud wall, and one dabbed onto the external wall. I’ve tiled two thirds of the shower area, directly onto what was left without treating the plasterboard with anything and only afterwards thought I may have made a boob.

That was two days ago. I flicked off a few tiles to see what was what and they came away easily, but the adhesive was still moist and crumbled when scraped. Some around the edge was firmer and the tiles came off almost clean and the adhesive stayed on the board.

Should I leave it a few more days and carry on if they have taken or rip them off which will certainly require new board as most of the adhesive won‘t come off. I’ve read a bit over the past two days about using aqua panel, plywood, PVA, don’t PVA, Bal primer, Bal APD and too be honest don’t know what to do for the best.

The tray is stuck down onto a new 18mm ply piece of flooring , so removing the boards has it’s pitfalls.

I can’t do anything now till the weekend, so I’d be very grateful for any suggestions on what to do.

 

[lucretius]

Depends on how bad the plasterboard is.
If it is solid (though missing its paper) then I suggest gripfilling the tiles on.
The main thing is this, the tiles must be firmly stuck in place, make sure you leave a grout line (use spacers) then pack the grout in with a rubber float.
As long as the grouting is done correctly and the tiles are firmly stuck then no water can get though.
Use bal grout, and run dow coning mastic (mould resistent) down every corner, and also shower tray, also worth going around shower and shower rail fittings as well

 

[Spr0cket]

No water will pass through the grout - are you recommending Epoxy grout then?

Regular grouts will allow moisture to penetrate - and that plaster board will be like a sponge when it does.

So you can restart with tanked surface or continue and change grout requiremtns to a fully sealing variant - which may or may not be more work, depending upon your grouting skills.

 

[Artisan Bathrooms]

I suggest gripfilling the tiles on.

Good old gripfill, eh ?

Two things:
1.

the adhesive was still moist and crumbled when scraped

Did you use a tub (readymix) adhesive? these can be good for small format tiles but only go off by losing their water through evaporation. ~If you've got big tiles this can take forever.. Answer, use a bagged cement based adhesive. You'll need to prime any plaster/plasterboards first using eg. BALs APD and you must use an adhesive with flexible additives on boards.
2.

Some around the edge was firmer and the tiles came off almost clean and the adhesive stayed on the board

This is a bit worrying.. Your tubbed sticky has gone off at the tile edges ('cos it's been able to lose water through the grout lines) but it's not stuck on the tiles. Some tiles have a powdery coating on the back that's a residue from manufacturing (mould release agent) so sticky won't stick. You've got to wash this off before you start.

Best Solution?
Rip it out - put up new boards. If you use plasterboard then tank onto shower tray after priming with manufacturers primer. Then re-tile using flexible cement based bagged sticky. Good luck.

 

[gcol]

Good advice by Artisan Bathrooms. Welcome to the forum.

 

[focaltucker]

Yes it's a ready mix adhesive.

The tiles are 200mm by 300mm so quite large. Over the last few days since I posted, they seemed to have stuck well and the adhesive has hardened properly.

I think I may have been a bit heavy with the amount of adhesive I've slapped on, as I have gone through far more than the coveraged suggested I should have. So I don't know if this has been the reason it took a while to do it's job?

I am thinking of carrying on...... I did originally buy some unibond waterproof grout.

Am I better getting the Bal stuff or is it pretty much the same?

 

[Artisan Bathrooms]

Thanks for the welcome gcol...

Can't really comment on Unibond grout focal... BAL is certainly good gear though, but I use Mapei myself. It's a bit funny to use if you're not used to it - sort of slides off the float and you wonder if it's even going to stick between your tiles... It does though and the finish is unbeatable - I hardly ever use anything else nowadays. If you do decide on mapei be aware that it goes off pretty fast - that's caught a few tilers out the first time they've tried it (err... myself included I recall..). Comes in 24 different colours too...

Enjoy...