What is this?

Hi

I thought this black stuff was bitumen but on lifting blocks around the edge of the room to apply a liquid DPM, i noticed that some of the black stuff is hard and chips away easily, whereas some of it is thick and tacky, and stinks to high heaven (of bitumen!).

So it looks like bitumen and smells like bitumen but I wonder why some of it is rock hard as expected (floor is original 1930's afaik) and some of it is still tacky. As an example, i can place a lifted block onto something and it will re-stick.

Any ideas please? Could it be some sort of later self levelling product? Or reacting with the original bitumen adhesive perhaps.

I am only really concerned as i can smell this stuff in other rooms, so apart from ripping up the lot and laying a sheet over it, am not sure if there is much else i can do. Is the smell/fumes likely to be harmful?

Any thoughts appreciated even if its just rip it up!

Thanks
Mike

lots of work and effort ripping it all up.
iirc thats hot bitumen or was when it went down to stick the blocks down.

What floor coving will you be putting down ontop.

Will either lay 15mm engineered board directly on top, or take up the blocks and lay a DPM, 20mm chipboard (to make up height), then 15mm engineered board.

Does this approach seem ok.

what's puzzling me is why some of the bitumen is soft and others hard, rock solid.

Thanks
Mike

Could be moisture over the years has broken some of the bitumen down.
Most floors I go over like that I have them asphalted 1st then put a latex screed on top.

dormermike said:

what's puzzling me is why some of the bitumen is soft and others hard, rock solid.

Click to expand...

I've had various samples of historic flooring with bitumen stuck to them sent to me, not unusual to see some hard and some tacky.

AronSearle said:

dormermike said:

what's puzzling me is why some of the bitumen is soft and others hard, rock solid.

Click to expand...

I've had various samples of historic flooring with bitumen stuck to them sent to me, not unusual to see some hard and some tacky.

Click to expand...

Thanks. Is it usual for rooms with historic floors and their rooms to smell faintly of bitumen? It's that which is driving me mad! The floor itself is sound in some rooms and aside from being a little fragile (is pine) I wouldnt get rid.