Removing PVA

[Happy Tiler]

Hi. Our newly replastered bathroom walls were pva'd as we were going to paint them but then decided to tile. I've tried my best to remove the pva, first with soapy water, then sandpaper, and brushed with stiff metal brush (don't know if I should have used a metal one!). Having put the first coat of undiluted BAL APD on, the walls look patchy and i'm not sure whether this is because some pva may still be present but i've been over them twice with sandpaper and brush. Will it matter greatly if there are small areas with still pva on? I'm using cement based adhesive.

 

[peteablard]

Walls can look a bit patchy sometimes when primed, if you've gone over it all with the methods you've said then you should be fine

 

[Time's Ran Out]

What size tile are you using?

 

[Happy Tiler]

What size tile are you using?

Hi, 400x250 mm

 

[Time's Ran Out]

As the PVA may have formed a skin, and even the undiluted APD can give a layer rather than allowing the plaster to breathe, the final decision rests with you! The tile size and adhesive choice are fine and you may be OK, but any advice cannot be guaranteed.

 

[Happy Tiler]

I took a couple of pics so you can see. Looks a bit sus to me, not that i've ever seen what pva looks like after prime's been put on!
I've never primed before as only ever tiled with smaller tiles using tub adhesive.
As you say, I could have I slapped it on unevenly. Of course I am a female so maybe I didn't put enough 'elbow grease' into it!

This section is the worst part in the whole bathroom on the centre wall between two windows. The other walls looks ok.

I'd really appreciate some expert advice on this.

 

[White Room]

It looks well scratched up, warm water would be the best to remove existing pva with a sharp scraper....

 

[Happy Tiler]

I started scraping off what i originally thought was pva residue because the walls looked patchy after coating walls with apd but i now think its the APD and it's formed a skin! When I started scraping off what I thought were patches of pva still present, the APD was peeling off. Should it goes like that? I followed the insructions on the bal adhesive bag which says to apply 2 coats of undiluted apd to newly plastered walls. The walls were well brushed with a stiff metal brush prior to application.
Please don't tell me I've got to remove it all again and apply a diluted solution :bigcry: I'm almost at my wits end.
I must admit to feeling a bit paranoid since reading horror stories about tiles falling off. It's not like i've never tiled before, I've done 3 bathrooms and 3 kitchens in the past bit I've always used tubbed adhesive with smaller tiles.

HELP!

P.S. Think I should change my username to 'Unhappy Tiler'!:lol: