Using brick slips as a bathroom floor over old bitumen

[jonathan]

Hi there everyone. What a fantastic forum. I have taken out the bathroom in our 1930s bungalow. The floor was tiled, and well stuck down. Removing the tiles has revealed a layer of bitumen painted onto concrete. The floor is solid and isn't likely to move. My question is this...what kind of adhesive should I use to lay my brick slip tiles onto the painted bitumen? (I am calling them slips, but my terminology might be wrong. These are the size of a house brick as viewed from above, but are only about 30mm thick).

Would any good flexible floor tile adhesive be OK, or does the presence of the bitumen mean I should be using something specific? BTW I intend to grout using a sandstone grout, and then seal everything with several applications of a tile sealer. Any thoughts?

 

[J K Tiling Cornwall]

Hi Johnathan, I would say if the bitumen is pretty old it should be quite solid and inert. I would give it a slurry coat with a S1 adhesive mixed with SBR diluted with water 50:50. Leave to set and dry out and tile with a S1 Adhesive. Must have been a old method of creating a damp proof membrane. Have tiled over similar in the past without issue. 👍