Black adhesive question

[Carts69]

Hi, I wish to lay ceramic tiles on my kitchen floor, having removed old cork type tiles, I'm left with a black tar like adhesive, thrown everything at this to remove it but with no success, I've heard that a slurry coat is the way forward, my question is... Can I slurry over this adhesive or will it require more scraping prior to slurry?

 

[dilalio]

What is the surface beneath the bitumin? concrete or timber?

 

[Carts69]

It's concrete

 

[dilalio]

Ok. This is something a tiler would rely on his experience for...

If the bitumen adhesive is "sound" ie: still well stuck to the concrete but no longer viscose and it is dried hard, then he would likely tile straight over it with a decent powdered cementious adhesive.

If in doubt he would first see how easily it came up with a floor scraper and then revert to a primer (BAL do a good one) or a mixture of the two if patchy.

I have done both in the past with no issues but it's an onsite touchy/feely judgement call!

 

[Saycheese5]

The bitumen type adhesive is probably there for a good reason. It looks like Damp Proof Paint and perhaps your kitchen had vinyl tiles when the house was built, which were in turn replaced by cork tiles. I'm saying that because I've got Marley type floor tiles, I removed a few and there was the same adhesive underneath them. I had to remove a section of the screed and there was no damp proof course between the concrete and the screed, therefore that black bitumen adhesive served a dual purpose, damp proof and adhesive. I personally would use an adhesive over it.