Boarding before tiling.

[Kempydiy17]

Hi All,

I know there is every likelihood that this subject has been covered, but I cannot find the answers to all of my questions in one place, so if someone has the time, I was looking for a bit of a walk through if possible?

I'm replacing an entire bathroom and whilst removing the old tiles, most of the backing plaster has also come away, leaving me with block work. Looking at the state of the remaining backing plaster, I've decided to remove all of it as I wouldn't trust it to hold any significant weight.

We have two choices when tiling - either floor to ceiling through the entire room, or bath to ceiling around the bath (this will have a concealed TMV shower at one end in studwork) and then tiling to chest height on each wall.

1) I'm going to board all the walls to allow a better chance of getting them truly plumb and square. Can I just use Gyproc Board Adhesive for the cement boards? Will the boards also need to be screwed to the block work? And will a basic PVA primer be sufficient on the block work before the board adhesive?

2) For the non-wet areas (window wall & wall opposite bath) will moisture resistant plasterboard be sufficient as I think this will drastically reduce the cost. What preparation will the MR PB require before tile adhesive is applied?

Any assistance would be greatly appreciated. Once this first phase is sorted out I will undoubtedly be back in touch with further prep questions.

Cheers,

Chris.

 

[PrenticeBoyofDerry]

1) The cement boards can be fitted using wall board adhesive and if tiling I would use a secondary mechanical fixing, once adhesive has set. A primer is not required to the walls, but will not be harmful to apply one. If the wall is dusty, remove all dust then dampen the walls down slightly prior to dabbing on adhesive.
2) For non-wet areas, standard PBs will do! MRs as designed to be tiled straight onto, I would personally tape up any joints.

 

[Kempydiy17]

Thank you.

The PVA to the block work was just to deal with the residual dust, so I'll go ahead with that. Wasn't sure if I needed to do anything else to the blocks.

I'm guessing I can drill through the boards and send a plug and screw through to the wall behind once the Dri-Wall has gone off?

So I can use standard 12.5mm square edge boards an tile direct?

Again, thanks for the reply. I can get started first thing tomorrow.

 

[PrenticeBoyofDerry]

You can tile directly on to plasterboards. British Gypsum have nailable plugs for the use of secondary mechanically fixings.
I will try find some info for you.
http://www.british-gypsum.com/~/med...m/SITE-BOOK/SITE-BOOK-Full-Publication-11.pdf
Section 6 page 252

http://www.british-gypsum.com/products/nailable-plugs

 

[PrenticeBoyofDerry]

If the area is not a wet area the standard PBs are fine, a good adhesive and grout will be adequate protection.

 

[jrh14]

Hi,
Using moisture resistant drywall (plasterboard) is perfectly acceptable for all non wet areas in your bathroom. The only preparation required prior to tiling is to tape all of the joints and corners with three coats of compound and sand as normal. You can tile directly over the plasterboard without any problems.
I would advise you using cement board in a shower but NOT to screw directly to the masonry. No plasterboard should ever touch wall due to moisture. Apply strapping to the wall first then screw your boards to the strapping. Again I would tape all the seams and even use a tanking system over the cement board. Tiles can be applied to this as well without any problems.
I hope this helps and your project turns out great.
Have a nice day, Ian @ JRHConstruction.