Would you have screed under an upstairs carpet?

[Sparky1979]

Renovating house and needed to get under the floorboards upstairs.
Under the carpet is as follows ... underlay, sheet brown paper, fibreboard then what looks like screed sitting on the floorboards.

Could this screed be asbestos insulation? Would you have put this under a carpet upstairs? It looks like last renovated 1970's so bang in the timeframe. Its not tiles (which is a positive I hope), about 1cm thick, very tough (though brittle under hammer) and slight grey colour (turning brown when wet).

Am I worrying about nothing? Reluctant to break it up too much without some guidance. I appreciate you cant get a definitive answer on here so have sent a bit off to be tested just wondered if anyone had any similar experience.

Thanks,

 

[lymmranger]

sounds very unusual to me.....

are you sure you haven't just come across some mis-guided DIY bodge???

remember plumbers and sparkies Never do a very good job of replacing floorboards after they have finished. A previous owner may have been trying to stop squeaks and level up the floor

some photo`s would be good