Help!: Tiling onto Painted Walls ???

[derekdickinson]

Hi guys, just been asked, well told, by customer to tile directly onto a painted wall, it's never been plastered its just drylined/ any advice on preparation. PVA, keying etc.. he is in a hurry for the wall to be done which I cant get to anyhow until Friday, but he's insisting it doesnt need any prep, think he's more worried about the bill !

[doug boardley]

definitely NOT PVA!! it should be ok as it is

[derekdickinson]

Hi Dave and Thanks for reply, new to this, can you give me a bit more detail why you wouldn't use pva? cheers.

[doug boardley]

Hi Dave and Thanks for reply, new to this, can you give me a bit more detail why you wouldn't use pva? cheers.

Dave will explain, but believe me if you have pva in your van,give it to a joiner!!

[doug boardley]

Hi Dave and Thanks for reply, new to this, can you give me a bit more detail why you wouldn't use pva? cheers.

ettringite failure, google it derek!

[whitebeam]

Or a plasterer

[BDS]

Or plasterer

[whitebeam]

Snap

[BDS]

Great minds think alike mate

[Dave]

PVA just forms a skin over the wall substrate and then when you put your adhesive on to it , it becomes live again and goes tacky...thus effectively decoupling your tiling....you need to use an impregnating primer..( i.e acrylic or synthetic)...these primers impregnate the substrate and make them stable for tiling when using cement based adhesive( as mentioned ettringite failure) and if using a dispersion adhesive then they stop the water suck from the substrate causing less open times...

[derekdickinson]

cheers lads, sorry but got to keep the PVA, do a bit of plastering occasionally, but thanks for the advice, will keep it right away from the tiling tools / jobs then.. very much appreciated, just been surfing through this site, such a wealth of information fantastic. thanks again , your a great bunch.

[pjc]

Had a phone call from my builder neighbor yesterday it went like this Pete just tiling this bathroom and the tiles are falling off i am holding them up at the moment waiting for someone to help me what are they 600x600 porcelain what adhesive are you using err bucket stuff so its pulled the paint off with it yes well you need to skim the paint with the bucket adhesive which will soften it then you will be able to remove the paint easily prime the wall with a APD then use cement based adhesive with admix in it builders a

[grumpygrouter]

Had a phone call from my builder neighbor yesterday it went like this Pete just tiling this bathroom and the tiles are falling off i am holding them up at the moment waiting for someone to help me what are they 600x600 porcelain what adhesive are you using err bucket stuff so its pulled the paint off with it yes well you need to skim the paint with the bucket adhesive which will soften it then you will be able to remove the paint easily prime the wall with a APD then use cement based adhesive with admix in it builders a

..

[doug boardley]

Had a phone call from my builder neighbor yesterday it went like this Pete just tiling this bathroom and the tiles are falling off i am holding them up at the moment waiting for someone to help me what are they 600x600 porcelain what adhesive are you using err bucket stuff so its pulled the paint off with it yes well you need to skim the paint with the bucket adhesive which will soften it then you will be able to remove the paint easily prime the wall with a APD then use cement based adhesive with admix in it builders a

Dereks walls haven't even been plastered, just painted straight onto p/board,so I don't think it'd happen in this case but builders a,most deffo!!

[BDS]

Whats builders name i`l make a note of not to ring him,,,

[pjc]

Whats builders name i`l make a note of not to ring him,,,

the wost thing about him he has built a monster of a house directly opposite my house i look out of my window all i can see is what looks like a great big ugly hotel must of knocked 50 g of the value of my house

[dahagsta]

Dez, there's an instruction video on Youtube that shows you how to do the prep work for tiles onto plasterboard:

YouTube - Paul Gambles Uncut

[whitebeam]

Had a phone call from my builder neighbor yesterday it went like this Pete just tiling this bathroom and the tiles are falling off i am holding them up at the moment waiting for someone to help me what are they 600x600 porcelain what adhesive are you using err bucket stuff so its pulled the paint off with it yes well you need to skim the paint with the bucket adhesive which will soften it then you will be able to remove the paint easily prime the wall with a APD then use cement based adhesive with admix in it builders a

Love it

[beanz]

Just another of my stupid questions, but if you leave the paint on the boards, will it not do the same as PVA and just add a skin which could fail under the weight of tiles!?!

[doug boardley]

Just another of my stupid questions, but if you leave the paint on the boards, will it not do the same as PVA and just add a skin which could fail under the weight of tiles!?!

would 've thought that if it was emulsion it would've absorbed through into the gypsum, thus not forming a skin, as it's water based and not poly vinyl acetate it shouldn't skin, unless,it (p/board) had already been primed

[beanz]

would 've thought that if it was emulsion it would've absorbed through into the gypsum, thus not forming a skin, as it's water based and not poly vinyl acetate it shouldn't skin, unless,it (p/board) had already been primed

Ah okay, cheers Doug. Always learning...

[doug boardley]

Ah okay, cheers Doug. Always learning...

me too mate

[Dave]

Ah okay, cheers Doug. Always learning...

Or a silk paint was used with out a primer coat( miscoat) and this will still peel.....

[doug boardley]

yes, there are a few possible scenarios, Derek had best check with client as to how p/board has been painted

[pjc]

Just another of my stupid questions, but if you leave the paint on the boards, will it not do the same as PVA and just add a skin which could fail under the weight of tiles!?!

would of thought it could need to ask a painter that one ? :Pete

[derekdickinson]

Evening lads, I have checked with the customer about how the walls were treated, he cant recall other than to say non have been plastered to keep the costs down, all have been drylined and painted only, drylining only means that they put tape on the joints and smoothed them over he recalls... The builders only used 9mm plaster board on the walls, so when the orignal tiles were pulled off by another chap, the wall came with it, I've had to rebuild two walls the other two still have the paint on, I've put some Gaffa tape on it for half an hour and when I peeled it off the paint stayed on the wall is this a true indicator which can safely be used.. Just want to say a big thanks to all for your help...

[doug boardley]

it's been emulsion then Derek, it's impregnated right in.It won't become live like pva. From your info, I think it is safe to tile straight onto, but priming with an sbr type primer will be advisable, but not pva!!!
Doug

[BDS]

And scoring it would aid aswell,,,,

[whitebeam]

12.5mm boards would have been better but 9.5mm just needs more stud work which hopefully was applied. Surpised that the builders used the thinner board, If the paint remained then your onto a good thing

[doug boardley]

builders boarded it whitebeam we would have used 1/2 inch board!