PVA or Not?

There are many products available for lining walls in the very situation you have.

Aquapanel being my preference for stud walls.

Tiles don't like wood, wood expands and contracts and tiles don't. Sometimes situations dictate that plywood is used rather than other substrates, but in your position you have a choice.

If your not using the area as a stand up shower and just as a bath, then plasterboard would actually be better than Ply as a surface on which to tile.

If you tiles the PVA covered wood, I'm not saying it will definately fail, but I am saying the chances of it failing are infinately higher than if you use aother product.

 

If you have used a really weak mix of pva and it soaked well into the wood, you might find it less likely to fail.
Am I right ?

Handyandy - really

 

I have used PVA in the past for waterproofing, but not really found it very good at the task - I used it to seal the cut edges of the shelf and backboard in my kitchen sink unit, but it failed miserably.

You should use BAL Bond, which is an SBR adhesive and far more water resistant than PVA. It can be used to seal ply (i have just done the rear faces of my new ply bathroom floor with it), and it can be used as a primer to give added adhesion.

You could be fooled for thinking that SBR is PVA, but is it not, it goes on the same way, and dries pretty quickly.

You should be able to get BAL Bond from most tile suppliers or plumbers merchants, I assume that there are other manufacturers of SBR primer out there as well.

 

I would use a good quality cement based flexible adhesive, and hope for the best. I dont think i've ever seen 18mm ply on walls before.

 

Yes Bal recommend Bal bond on the underside and the sides of the board but they dont normally recommend doing anything to the top side of the ply before tiling, this is for floors though, cant comment on walls.

 

Take it down and start again, you're in a position now where that's pretty easy to do and not expensive.

Replace it with a product that you know won't fail.

 

PVA is the problem, Plywood is the problem, the combination of the two will create a failure more than likely.

You can't cover the PVA, my advice is take it down and replace it. £70 isn't a whole lot of money compared to a failed tiled bathroom.

 

Leave the ply up and just overboard with tile backer board, less cuts and less waste.

 

pva

 

tiles a pyke's mobile caravan once that was ply, had to use melted down tyres to adhere them and keep the joints clear, what a nightmare, mudster, what was the name of that ol' gear, came in a red bag and a 2.5lt solution to go with it....

 

Go to Wickes and buy some Aquapanel, it's under £12 for a 1200mm x 900mm sheet and can be screwed directly onto your ply. No need to find studs, just straight on. Use the ceramic coated screws that are normally on a shelf next to the aquapanel and apply the glass fibre tape with your tile adhesive over the joints of the board. Once dry you are ready to tile.

 

Looks like a wind up to me. Not answering your replies and just coming up with other daft options:^O

 

OK bojo. If you are not going to fit your tiles onto the pva, how about trying to remove it ?

Get yourself some metholated spirits, a terylene-type towel or flannels as rags. Paint on the meths(goes everywhere) and wipe off with your rags. Have many rags, as once wiped the pva gunks up the rags quickly.
Then wash down with water and allow to dry.

Then use one of the proprietry sealers mentioned above, and off you go.


Handyandy - really