I am in the process of stripping back my bathroom. As the pictures show, I have removed the tiles but taking out the tile glue has also removed large chunks of render. Can I fill those holes with a new coat of render or do I need to completely strip back the old render? Everywhere I have looked on Reno sites indicates there is no easy way to remove the old waterproofing. Can anyone give me ideas on the best way for this job?
You'll need to remove the current waterproofing and glue, returning the wall to cement with an angle grinder and flap disc or twistknot wire brush. Once you have a clean surface, you dampen it down with water and use Lanko 5kg 136 Rapid Patching Mortar to fill the damaged portions. After the Mortar has cured, apply Davco PrimeX to all surfaces and then waterproof. You can then use SMP Evo as your tile adhesive.
An alternative way to get a level surface to tile upon would be to install a timber frame and clad that with Villaboard. Waterproofing will then need to be applied over the top.
You should find these step-by-step guides useful:
Please let me know if you need further assistance or have questions.
Thanks for your reply Mitchell,
The villaboard option sounds much less labour intensive but it’s already a small space and that would make it even smaller. I think I’ll have a go with the angle grinder and flap disc ... what grit do you recommend for the disc?
The Villaboard option does give you a new surface to work with, but the loss of space can be an issue, @JumBuck.
I recommend trying a disc designed to remove coatings like the Flexovit 100x16mm Stripping Ripper Grinding Disc. Alternatively, a Josco 127mm 40g Ceramic Flap Disc. I'm a little concerned they might fill up quickly with the glue and waterproofing membrane. If they do, you could try a traditional grinding disc.