Asphalt screed with Gerrix 1.5cm impact sound insulation

Dear users,

I want to buy and renovate a house in Bavaria (built in 1963) and came across the following in the documents:
Floor: 2cm asphalt screed with Gerrix, 1.5cm impact sound insulation, above that was an oak parquet.

Should I remove the screed during the renovation or leave it and try to install the underfloor heating on top of it? Or skip the underfloor heating if it’s too much effort?

What is Gerrix? Do you think it might contain PAHs? I couldn’t find anything about it on the internet.

Best regards and thank you!

"Gerrix" glass wool was manufactured, for example, in Bergisch-Gladbach. Whether it was suitable as a TSD, I do not know. However, I have often found glass wool under screed floors that was completely compressed and apparently did not have the required quality to be used as TSD. Such a construction cannot be reused during renovation.

Asbestos or PAHs may be contained in the parquet adhesive. The asphalt screed may also possibly contain asbestos or phenols, etc. In any case, I would have all the building materials analyzed before removal in this setup and then completely remove them down to the raw ceiling. To install underfloor heating with wet/dry screed, you need sufficient build-up height including a new TSD and, if applicable, a leveling compound on the uneven raw ceiling. A wet screed could potentially mean too much weight load for an existing ceiling. This must be checked structurally beforehand.

In addition, floor insulation may also be required according to the Building Energy Act if it is a floor construction against the ground or above unheated (basement) rooms. The sufficient heating output of the underfloor heating must be demonstrated by a heat load calculation according to DIN 12831.