To skim or not to skim?! Advice and information on tiling and fixing tiles to a variety of surfaces

[diylearner]

I have stripped my bathroom and intend to tile some areas and paint others. When i removed the existing wall coverings and tiles I found that the walls were quite rough and bumpy with chunks of mortar missing in some areas, especially where the old tiles were. With this in mind I've spoken to a plasterer about skimming the entire bathroom so that I would have nice smooth walls to tile and paint on. However, I have also spoken to an experienced DIYer and he has suggested that it would be better to only skim the areas that are to be painted, and just unibond the areas to be tiled and then tile straight onto the existing surface as it will provide a better key. Also it will save me money by having less of an area skimmed. He also said that tiling over a thin layer of skimmed plaster could result in tiles popping or falling out over time. All of this seems to make sense to me but I'm a bit concerned about being able to get the tiles level if I lay them on the existing rough walls. I guess I'd have to just make sure they are level and flat as I'm going along but as this is my first attempt at tiling I'mthinking that a nice smooth flat new layer of plaster would make the job easeier for me! Can anyone offer me some advice on this?

[rosebery]

1. You'll NEVER get the tiles up properly if you try and put them on rough walls. Either that or you'll use so much adhesive that you'd wished you'd plastered first. Think of the cost - how much is a 25kg bag of plaster compared with a 20kg bag of decent addy?

2. If you only skim the area to be painted firstly you'll not only give the plasterer a headache you'll give yourself one as well trying to level up tles with skimmed wall. It really is going to take him no longer to skim the complete wall than it is to skim half of it. Have you seen how fast they can work?

3. If you PVA then tile the tiles will fall off!

4. He is quite wrong about tiling over plaster skim. If he's done it before and used PVA then the tiles will have fallen off but thats because he used PVA to prime and not a proper acrylic primer like BAL APD.

5. You are correct a nice smooth flat layer of plaster would make the job so much easier for you.

HTH

Cheers