painted plasterboard

[huckin]

can you tile straight onto painted plasterboard as in the past i have without prime in and not had a problem but is that more buy luck

 

[faithhealer]

If it's soaked into the plasterboard and there's no possibility of removing it then prime.

 

[diamondtiling]

Its not an ideal surface to tile onto, I would want to remove it.

 

[Sean fsy]

priming it will may also soften the paint and make it worse to tile onto than if you had left it.

 

[tfs]

I agree with the above comments. Its deffo best to remove plasterbaord and replace with new. If you dont do this then I would at least abrade the surface, prime and then score full area with a knife to get a better key.

 

[tfs]

you only need to cut out the area that you are tiling. I would then put axtra noggins into the stud to allow you to get horizontal fixings with the new peice of plasterboard.

 

[tfs]

I posted some pictures a while back, clink on the link to see an example of cutting out old plater board

http://www.tilersforums.com/tiling-forum/19577-wall-tiling-advice.html

 

[grumpygrouter]

I agree with the above comments. Its deffo best to remove plasterbaord and replace with new. If you dont do this then I would at least abrade the surface, prime and then score full area with a knife to get a better key.

This will probably ruin the integrity of the plasterboard if you score through the paper surface and make the plasterboard weak. It will also expose the gypsum to the cement adhesive if you prime first and not afterwards.

 

[tfs]

This will probably ruin the integrity of the plasterboard if you score through the paper surface and make the plasterboard weak. It will also expose the gypsum to the cement adhesive if you prime first and not afterwards.

Idealy you woudnt tile over the paint at all.

scoring paint on plasterboard is the way it has been done for years mate and still is. You dont need to slice right into the plasterboard. you are trying to get a key, abrading and priming alone would be weaker than scoring.

 

[tfs]

This will probably ruin the integrity of the plasterboard if you score through the paper surface and make the plasterboard weak. It will also expose the gypsum to the cement adhesive if you prime first and not afterwards.

Unless Im mistaking grumpy you have have actualy suggested to someone in the past that they remove adhesive from plasterboard with a wall paper steamer.

Would this not ruin the intergirty of the plaster board?

I know a few guys do that methhod but, this could remove skin of plaster board and it would deffinatly drive moisture into the platerboard as thats what steam is.

I would understand you challenging my advice if it was totaly incompetent

 

[grumpygrouter]

Softening adhesive with a steamer is relevant to dispersion adhesive and it is only to soften the adhesive to aid scraping it off. The same caution needs to be applied so the paper coating of the board isn't damaged. I personally abrade any painted plasterboard back to the paper surface and no further. I can agree that scoring will give a "key" but if you penetrate the paper surface you are weakening the board as that is what gives it it's strength. Wheather it has been done that way or not for years doesn't make it "right"imo.......pva has been used as a primer for years too....

Oh, and i wasn't "challenging" your advice nor was I suggesting your were incompetent and I don't know why you mentioned that. I was giving an opinion to your response as that is what the forums are about...help, advice and debate. If you think what I said is wrong then that is fine, but at least the readers have now been given a different opinion to consider if the situation arises for someone else.

 

[White Room]

Personally I would use a course abrasive oxide paper to break the surface of the paint on the board, scoring with a knife would weaken the board.

The paper is what give's it it's strength

 

[tfs]

If I had the choice I would do neither the tiling on to paint (I would resheat the area being tiled) and I would not choose to use a steamer on plasterboard to remove adhesive (I would again choose to resheat) applying hot steam to a substrate like plaster board would do more damage than scoring the paint. Plaster board is not designed to be resistant to any kind of moisture especialy at a heat that will weaken and strip the paper face of it.

and to be honest scoring paint is not comparable to using pva as a primer.

 

[Stan001]

Why has nobody mentioned 1. The tape test? (a recognised test) and 2. Asked what tile he is intending on installing (ref weight limit) ?


If the painted wall passes the tape test (in several locations to be safe) and the tiles are lighter than the holding weight then the paint is doing the job of the primer.


If it fails the tape test or the weight is higher than the holding surface then replace the plasterboards (cheap and easy job – and very much cheaper than replacing tiles falling off in 6 months)

 

[grumpygrouter]

If I had the choice I would do neither the tiling on to paint (I would resheat the area being tiled) and I would not choose to use a steamer on plasterboard to remove adhesive (I would again choose to resheat) applying hot steam to a substrate like plaster board would do more damage than scoring the paint. Plaster board is not designed to be resistant to any kind of moisture especialy at a heat that will weaken and strip the paper face of it.

and to be honest scoring paint is not comparable to using pva as a primer.

I never said it was, it was an anolgy I used to illustrate that just because it had "been done that way for years" that it doesn't necessarily make it right. Everyone has their own way of doing things and that is what the forums are for, to allow people to read the advice given by contributors on here, compare that advice, contradictory or not, and then make their own informed decision from that information. I think we both agree though that it would be better to re-sheet than waste time removing adhesive or paint if possible. It isn't always possible though!