Can you tile over painted plasterboard?

[Kiefeng]

We're planning to tile our powder room wall to 1.2 meter high with porcelain tiles. The existing wall is Gyprok plasterboard which was painted with Dulux Wash and Wear. The paint is still in very good condition.  

I have seen mixed suggestions on the net with some recommending to sand the paint off to provide better adhesion whilst others suggest it is okay to tile over the paint.  

Should I remove the paint?

[mickcous]

I think the best way to think about this your tile glue is only sticking to the surface. It is not going to penetrate through the paint. So if your paint is in good condition and is not going to peel of easily it should be fine.

We regularly tile over painted walls. Be sure the glue you use will stick to paint and does not need the walls to be primed first. I also like to put a few more fixings into the wall also just to be sure, especially if you are adding a lot of weight with the tiles. Only going to 1.2 m will be fine.

If the paint peels off easily with a paint scraper, then you should remove. 

Hope that helps.  

[EricL]

Hello @Kiefeng 

Welcome to the Bunnings Workshop community. It's wonderful to have you join us and thanks for sharing your question about tiling on your wall. 

It's great that you've received excellent advice from @mickcous. 

The issue with tiling over paint is that you can't tell when the paint will fail. When paint fails in a particular area anything attached to it will fail with it, hence the tile adhesive along with the tile will fall off your wall.

I suggest heavily sanding the surface of the wall using a Flexovit 115mm x 5m 80 Grit Painted Surface Sandpaper Roll - 80 Grit. This will scratch the surface of the paint and plaster providing a good surface for the tile adhesive to anchor onto. Please makes sure to clean the surface very well and wiping off all the sanding dust before tiling.

Here is a handy step-by-step guide: How To Tile A Bathroom (the techniques used are applicable to your project)

If you have any other questions we can help with, please let us know.

Eric

[EricL]

Hello @mickcous 

Welcome to the Bunnings Workshop community. It's wonderful to have you join us.

Thank you very much for sharing your knowledge and experience. Let me tag @Kiefeng to make sure they see your suggestions. 

Were keen to hear more about all your projects and plans around the house and garden. Please feel free to reach out and whenever you need assistance or would like to share a project with the community.

Eric

[Kiefeng]

Thanks mickcous for the advice.

[Kiefeng]

I tried sanding off the paint using a Festool Rotex sander with a paint removal disc without success, the paint just won't come off after 5 minute of spot sanding . I then contacted Dulux technical support for advise. Ashur of the technical team suggested that it's easier to replace the plaster board. He said it's nearly impossible to remove the paint without damaging the board. I think I'll follow Ashur's advise to replace the plasterboard.

[MitchellMc]

Hi @Kiefeng,

To clarify, @EricL wasn't suggesting that you sand the paint entirely off, but rather abrade the wall and add scratches all over it to key the surface.

Mitchell