ᐅ Is the stone wood screed made with asbestos? Because it doesn’t burn.

Hello. I bought a house from the 1950s. I removed the PVC flooring and noticed a soft subfloor underneath, probably wood chip screed. Can I simply remove the adhesive residues with a stripper? Could it also be asbestos? I tried to burn it. It just turns black but does not catch fire. I took a picture.

Hello questioner,
Why would a magnesite screed catch fire, I wonder? The majority of such screeds (which, by the way, are becoming popular again) consist mostly of caustic magnesia and only about 8-10% organic components.
That is too little to bring these components to ignition temperature.
What you have found cannot be determined from a distance.
It is definitely not magnesite screed, since it is either very hard or, when exposed to moisture, can be scooped out with a teaspoon. No joke!
As for asbestos being present, a relatively inexpensive analysis using a scanning electron microscope can provide clarity. It cannot be completely ruled out because some manufacturers used such additives in magnesite screeds up until the 1960s.
"Don’t give in to fear," as the saying goes.
So for now, consider what is unproven as possible, but not as fact.
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Best regards, KlaRa

Hello. Alright. So the screed is quite hard. I broke out the piece using a Bosch hammer drill.