Tiling onto plasterboard

[0Floz0]

Hi

I’ve got some of the blue plasterboard being delivered tomorrow. I know the majority of advice is to tile onto cement board. But hoping it’s going to be quicker and a bit cheaper using the moisture board where there is no direct water contact.

I’m just ripping things out and I’m amazed that the plasterboard is in such good condition underneath as they’ve just used standard plasterboard and I can’t see any evidence of sealer or shower waterproofing kits (which is what’s tempted me to use the blue board). This bathroom was done 15+ years ago.

The tiles are stuck solidly so I’m smashing it all out so no chance of reusing the board.

I’m hoping I can get some advice on a couple of questions.

Plasterboard: this won’t be in any of the areas with direct contact for water (was going to cement board these parts). Would you do anything special for the joints on these. Is it just using alkali resistant tape and running some flexible tile adhesive over it?

Is it necessary to prime the boards and would you use Sbr for this? Seeing mixed messages on this one.

2 of the walls are internal so are just studs. I’m fine with that.

However, the other two walls are brick. If I go back to brick, the plan was to use plasterboard adhesive foam (I find dot and dab too fiddly). Do I need to use mechanical fixings as well? Any recommendations?

I’m redoing the floor with 18mm ply and putting 6mm Hardie board on top. Any recommendations on cheaper screws? The branded ones have a hefty mark up! All the threads on that question are pretty old so thought I’d double check.

Cheers!

 

[Wayners]

I just used tile sealer on plasterboard in my shower 20 years ago and still good.
I didn't know any different at the time..
I just filled joints with whatever I had. Sealed with BAL sealer and white star adhesive.

 

[0Floz0]

I just used tile sealer on plasterboard in my shower 20 years ago and still good.
I didn't know any different at the time..
I just filled joints with whatever I had. Sealed with BAL sealer and white star adhesive.

Thanks Wayners. So seal the plasterboard then once tiled and grouted use BAL sealer to seal the tiles?

I’m using ultra s1 spes flexible adhesive and Mapei ultra colour plus grout if that helps.

How often would you screw the plasterboard onto the masonry if you were using plasterboard adhesive?

 

[Wayners]

Bal tile seal the plasterboard.
Tile
Grout

I never sealed tile grout

2008 Ish I guess.

This picture is today

 

[0Floz0]

Bal tile seal the plasterboard.
Tile
Grout

I never sealed tile grout

2008 Ish I guess.

This picture is today

I can’t seem to find a product called bal tile seal. Would Sbr have the same effect?

The masonry wall is a bit patchy as it was plasterboard dot and dabbed onto a plaster on brick surface. I’ve knocked all the plasterboard and dot and dab off. But it’s got some chunks out of it. As I’m using plasterboard foam for the bonding, do I need to Sbr the wall or will it grip fine?

Assume as I’m tiling large format tiles that I’ll need to put some mechanical fixings into the plasterboard too?

 

[RrogerD]

What do the tile instructions say?
When you mentioned "large format tiles", I start to get nervous. They are bloomin' heavy!
Definitely include mechanical fixings but tbh, why not use hardi-backer, mechanically fixed and be done with it? It seems it would solve many of your queries. In the scheme of the whole project it probably would be much easier extra in cost.

 

[0Floz0]

What do the tile instructions say?
When you mentioned "large format tiles", I start to get nervous. They are bloomin' heavy!
Definitely include mechanical fixings but tbh, why not use hardi-backer, mechanically fixed and be done with it? It seems it would solve many of your queries. In the scheme of the whole project it probably would be much easier extra in cost.

The tiles are 18kg per m2 (only 9mm thick) so with 4kg for adhesive its under the 32kg/m2 limit for plasterboard. It’s just a cost save for me tbh. The Hardie boards are being used over the bath for the water resistance. But to do all of the walls in it would add at least another £400 to the cost. It’s £112 for the plasterboard for 3 walls including the 2 longest ones versus £150 for one small wall.

How often would you fix it mechanically? It’s going to be a pain drilling into the masonry to do them so don’t want to overdo it.

The tiles didn’t come with instructions but these are the ones I bought. https://www.wallsandfloors.co.uk/modern-stautario-polished-600x300

 

[Wayners]

BAL background sealer.
What I used on plasterboard I think. Several versions so maybe phone technically to confirm its correct

https://www.easybathrooms.com/bal-prime-apd?gad_source=1&gclid=Cj0KCQiA7NO7BhDsARIsADg_hIZQdc4n5n--zbatp63gpezoIos6r8NT5y1tCgLCN1eJuRRj4SFOrpcaAkjsEALw_wcB