Tiling over old adhesive - yes or no?

[Rich_W]

I've removed some old tiles from my bathroom wall and in some places the old adhesive is still on the wall.

My feeling is that I should try to remove this before I re-tile, to get a solid bond between the new tiles and the plaster. Can anyone confirm that this is the case?

If so, what's the best way to remove the old adhesive from the wall - is it simply a case of a wall scraper and plenty of elbow grease?

 

[bathjobby]

You should remove all loose adhesive but then you have to be careful that in removing the more stubborn stuff, you don't damage the wall surface underneath. Particularly the case with plasterboard walls, you can end up stripping all the board covering off the plaster. Also depends what surface size you are talking about. I recently refitted 2 bathrooms, so was replacing a lot of tiles. I purchased the cheapest belt sander (less than £20) I could find, mask, goggles and overalls and went over all the remaining adhesive. After you have cleared up all the dust, in order to get a good fix with your new adhesive you must PVA bond all surfaces you want to re-tile. Basically 1 part PVA to 4 parts water (instructions on the tin) and seal the whole area with a big brush, really easy. If in any doubt, 2 coats.

 

[Rich_W]

Thanks for the details.

On a slightly separate note - I'd like to tile a wall which is currently painted. Would it suffice to coat this wall with the same PVA mixture.

I'm not too keen on removing the paint from the wall before tiling, but if I have to, I will...

 

[bathjobby]

Same really. Remove any loose paint (light hand sanding will do) then PVA seal. Before tiling score the wall with something like the edge of a stripper to provide a key for the adhesive to get hold of, score both ways diagonally.

 

[Rich_W]

Thanks for the tips - very helpful.