Hello,

We had asbestos tiles removed from our flat as they were cracked and posed a risk. What’s left is a concrete substrate and a bitumen residue. The asbestos removal people said it would cost £6-7k to remove and that it would anyway be better to just do a self levelling screed.

As we’re more than happy to have a concrete topping (like cemflow for e.g.) as a final floor, we were just going to follow the advice from Wacol in their video about levelling over bitumen, but the quantities are too vast for us and they don't sell them any smaller and their self leveller is not a wearing surface.

Does anyone have any advice on products to use when levelling over asbestos-containing bitumen so that a wearing concrete can be poured and trowels without (too much) risk of poor adhesion and/or cracking?

I also feel like I'm going round and round in circles. I think my number one concern is, because we can't abrade/key the bitumen, the DPM + primers alone might not create a good enough surface for adhesion of the topping. 

I feel a bit like I'm going mad and a lot of the information is really hard to come by or very dangerous sounding (a lot of people on forums being like, “oh just chip the asbestos bitumen off, I did it and it was fine!!!!”, I am just not going to do that!).

It can't be a super uncommon problem given how common buildings from this era are! There must be a solution! Please help!