Pva

[Eddie]

I have a wee problem. I am meant to be starting a bathroom this week, the lady came along to tell me it was ready to go, but then let me know that they had PVA'd the new plasterboard. Can PVA be removed from plasterboard? or is there anything that we can do without replacing all the plasterboard?

Cheers, Eddie

[Ajax123]

I have a wee problem. I am meant to be starting a bathroom this week, the lady came along to tell me it was ready to go, but then let me know that they had PVA'd the new plasterboard. Can PVA be removed from plasterboard? or is there anything that we can do without replacing all the plasterboard?

Cheers, Eddie

belt sander should take the most of it off. loads of dust though......

[Eddie]

I didn't wan't to use a sander on plasterboard.

[mikethetile]

i was going to say sand it

[Eddie]

Would priming over pva help?

[Ajax123]

Would priming over pva help?

Nope......sorry

[mikethetile]

problem is you cant prime over pva Eddie

there is a thread on here that covers this and will explain it better than me

[Eddie]

Suppose it will have to be sanded.
if it goes too far i will just have to replace the boards.

[Ajax123]

main problem is thart PVA mainly stays on the surface as a film and very little penetrates the surface of the plaster. This means the mechanical key is relatively weak compared to a penetrative acrylic or epoxy primer. the only realistic way to get it off is to scarify it some how. wire brush, sander etc. There are one or two enclosed sanding systems available that limit the dust. The other issues are that if it gets wet (water based adhesive???) it re emulsifies. That will cause the tiles to fall off. Additionally if you can get them to stick Poly Vynil Acetate is highly susceptible to alkali burn which breaks it down over a period of time.

Has no place in tiling I am afraid.........

[mikethetile]

main problem is thart PVA mainly stays on the surface as a film and very little penetrates the surface of the plaster. This means the mechanical key is relatively weak compared to a penetrative acrylic or epoxy primer. the only realistic way to get it off is to scarify it some how. wire brush, sander etc. There are one or two enclosed sanding systems available that limit the dust. The other issues are that if it gets wet (water based adhesive???) it re emulsifies. That will cause the tiles to fall off. Additionally if you can get them to stick Poly Vynil Acetate is highly susceptible to alkali burn which breaks it down over a period of time.

Has no place in tiling I am afraid.........

thats why i didnt try and explain

well explained ajax

[Dan]

main problem is thart PVA mainly stays on the surface as a film and very little penetrates the surface of the plaster. This means the mechanical key is relatively weak compared to a penetrative acrylic or epoxy primer. the only realistic way to get it off is to scarify it some how. wire brush, sander etc. There are one or two enclosed sanding systems available that limit the dust. The other issues are that if it gets wet (water based adhesive???) it re emulsifies. That will cause the tiles to fall off. Additionally if you can get them to stick Poly Vynil Acetate is highly susceptible to alkali burn which breaks it down over a period of time.

Has no place in tiling I am afraid.........

Well put mate.

[Eddie]

Thanks guys, you have just confirmed my thoughts.

Cheers, Eddie

[Dave]

Wet the wall lightly.. and then rub over with a scotch pad.. DO NOT soak the wall...

BUT if the pva was diluted to the extent it did not create a skin , then it will be ok to tile over.

[Ajax123]

Scotch Pads - wot a good idea. Dave the Save....you da man

[aqua blue]

I didn't wan't to use a sander on plasterboard.
__________________

It's a 'long shot', but a hairdryer may heat it enough so as it could be peeled off.

Works with vinyl film, some acrylic paints and stubborn masking tape.

[Eddie]

Cheers, Dave, That sounds like the best optoin so far.


Cheers, Eddie

[Dave]

The best test is to lightly wet a small area...then rub with your fingers,... if a skin rubs off then it needs to come off... simple as that really..

Please note.. DO NOT soak plasterboard..

[Eddie]

I've just been along to see this bathroom. The PVA was put on neat, it has a thick shiny coating over it now. Won't be too easy to rub off, i think.

[paulyoung666]

if it is neat , have you not just tried to peel it off ?? , worth a go if nothing else

[tiling spread]

i think it mite if you mark out the walls that you are tiling up to say 1/2way then scrach up the walls with a knife or just plaster it but find out if it was mixed with water first m8te ha ha that happend to me
started s new job new lab last year to plaster a 3bed house over artex and 26 new 8*4 plasterboard old walls
crashed out the 3bedrooms left the lab to prep&sheet up on the weekend
came back the next week arsked whats the mix for the plasterboard then as he had used it all
then went on to say that it went on neet clever boy i was soo happy that i just had to throw the bucket trowel at him and i got him too numty what aday i had i used a good ruth sandpaper on a sanding pole then just use a knife
its all good fun lads keep your pecker up dont let it get to you just put it on the bill

tell you what get them to get it plasterd give them my number and we will go halfs

[tiling spread]

nice and shiny then just flip the boards over if theres cuts then you will have the use new board on them

[whitebeam]

Your only supposed use one side of the board, the light side