Wall preparation advice please

**scoobysnax** · 08-10-2011

Hi, I am about to start tiling our bathroom and would like some advice on wall preparation. When I removed the old wall tiles, I inevitably damaged the 'drywall' surface to which they were attached. I have now ripped out the remaining 'drywall', and replaced it with new 'Gyproc 9.5mm Handi-board'. Can someone tell me if I can tile straight onto this surface as it is, or do I need to have it skimmed with plaster first?

Also, on the solid brick walls where there was no drywall (just a skim of plaster), some of the original plaster has come away with the tiles. The remaining sound plaster still has the tile adhesive on it.

My questions are:
Can I (a) fill in the areas of missing plaster with polyfiller and then apply adhesive & tiles onto that, and (b) apply the new tile adhesive straight over the top of the old adhesive prior to tiling. The area does appear to be sound, and I thought the existing rough surface created by the old adhesive would create a surface that would give good adhesion for the new tile adhesive. I have a feeling I might get laughed at on this, but just want to know if this is ok to do. If not, could you tell me what I will need to do to get a suitable surface for the new tiles.

Many thanks,
Scoobysnax