Tiling onto bitumen tanked wall

[jon ccc]

I did not find much in the search results about whether a bitumen wall can be tiled.
In my bathroom, I waterproofed an ordinary new-plasterboard wall with this dampproof liquid, "Bostik-Flexible-Liquid-Damp-Proof-Membrane-2". On it im planning to use "Mapei Floor & Wall Tile Adhesive Grey 20kg" to fix 30x30cm ceramic tiles.

After discovering in a post that bitumen can not be tiled over. i checked the bostik contents, and found it was 'bitumen and rubber latex aqueous dispersion', according the data sheet tds00461.pdf.


my questions:
1. can i tile over the bitumen without doing anything else to it?
2. or do i need to seal/ prime the bitumen before tiling? and what with?
3. would it just be easier to get new plasterboard [ my local b. merchant didnt have the waterproof type, so that is why i decided to waterproof the normal-type plasterboard]

Thanks

 

[Paul C.]

Not worth the risk. If Bostik say don't do it, then don't do it. The product you have used is designed to provide a damp-proof course beneath a screeded substrate i.e, the layer before a sand:cement screed.

You should have bought a shower "tanking" kit, such as the BAL WP1 or Ardex WPC. Mapei also got one called Mapegum but not had any experience with that one. completely different kettle of fish to the damp-proof.

If the bitumin isn't coming off any time soon, then your options are to overboard with new plasterboard or hardie backer and tank it, or get a waterproof boarding such as Marmox or Wedi. With these, you only need to waterproof tape the joints. No tanking needed. all of these will need screwing to the studs as you can't rely on adhesive sticking to the DPM.

 

[L95]

Overboard as above suggested.