Just had the bathroom skimmed and will be part tiled and part painted.

Plan was to apply a mistcoat to the plaster and then tile/paint as required.

Would people recommend waterproofing the shower area before tiling?

Thanks

Yep …pva is best…do it really strong
But the better way would have been to use Aqua panel for the tiled areas…!!

never, ever, ever, ever, ever use PVA on a plaster surface that is to be tiled. PVA is water soluble, it will skin over on the surface and then the water in the tile adhesive and through use will dissolve it and everything will be loose.

Don’t paint where you are going to tile either, best thing to use before tiling is a acyrillic tile primer straight to the plaster, you could also paint the wall with a tanking paint to waterproof it more before tiling.

Thanks all.

So mistcoat where its going to be painted and tanking paint where its going to be tiled.

Blazin-saddles – Member
never, ever, ever, ever, ever use PVA on a plaster surface that is to be tiled. PVA is water soluble, it will skin over on the surface and then the water in the tile adhesive and through use will dissolve it and everything will be loose.

Don’t paint where you are going to tile either, best thing to use before tiling is a acyrillic tile primer straight to the plaster, you could also paint the wall with a tanking paint to waterproof it more before tiling.

What are you talking about Willis???

PVA Bond is a multi-purpose bonding agent, primer, sealer, cement and plaster admixture that adheres to most common building and DIY materials. Ideal for priming unsound surfaces prior to plastering or painting, as an adhesive on wood, cork, textiles and most applications where at least one surface is porous, for general dust sealing on flaking paintwork/walls etc and as a cement and plaster admixture. Fully conforms to BS 5270. ..

Mist coat the plaster even where tiling to prevent the adhesive drying too quick due to moisture being pulled out by the plaster.
The shower area is best done with backer boards as they are waterproof and stronger than plaster board but if you’ve already plastered it’s too late. I recommend using a shower waterproofing kit. I used the one below a few months ago and it basically leaves a rubber coating for you to tile over. Very easy to use too.

http://www.tilemountain.co.uk/accesories/wetrooms/waterproofing/mapei-shower-waterproofing-kit.html?gclid=CK6L9oOO-sgCFQgcwwodX-IOIg

Eaxctly ^ pva is a sealer….. Tile adhisive works on the premise it can absorb into a surface to bond… Ie the tiles will only be as strong as the bond of pva to the skim….. And as for painting mis coat about a inch past tiles. As again the adhisive will stick to the paint and not the skim…

Seen too many “bathroom fitters” do this and after steam gets involved tiles start to pop. I know as thats all i seem to be replacing at the moment on my jobs.. Blown wall tiles and blown floor tiles where the screw centres seem to be non existent and some rough arses aint even laid ply over boards….

Don’t use PVA. As above use tile primer and a tanking system for really wet areas. I used the Mapei one and it seemed decent. Be careful if using very heavy porcelain tiles as the weight limit for skim is less than for straight onto boards. Can’t remember the exact numbers but available online and remember to include weight of adhesive. IANAT but spent ages online, phone calls to British Gypsum, Mapei, etc. etc. during a house refurb. The bloody tile shop I bought the tiles from even told me to use PVA even though they sold the flipping primer in the shop!

I’ve been a tiler for 20 years, the highest failure rate in bathrooms is from either PVA coated walls or painted before tiling. Lots of builders and plasters tell the customer to PVA walls but it’s just plain bad advice.

The best surface to take tiles for both adhesion and weight capacity, is cement board such as no more ply in 12mm, I’d only go to that expense and trouble in a shower area though and possibly the bottom half of a bath unless large format tiles are specied in which case I’d opt to do the lot, after that plasterboard without skim, after that, skimmed plasterboard.

Don’t mist coat a wall that is too be tiled, the tile primer will do the job of slowing down the ‘suck’ so it dries at the correct speed and doesn’t loose the moisture too fast. The tanking paint will waterproof the boards to some extent depending how much you do and is quite cheap to do so worth it IMO.

Many thanks all, surface is skim over sand/cement so will prime the area to be tiled and waterproof the shower area.

Rest will be mist coated for painting.

Looks like I will have to change my ways…..looking into it further…it seems pva is NOT the best idea.
I apologise to blazing saddles 😳

Not a problem. I just like to see things done in the rigt way, we all learn new things every time we do a job.

And that Ladies and Gents is how the construction industry deal with differing views,an inspiration to us all,#proudofyouguys 🙂

+1 don’t use PVA. I used some Mapei aqua dry I think it was called when I fitted our new bathroom, seemed to be good stuff and no probs so far. You can pick up a tub from screwfix.