I would not so easily jump on the topic of "mastic asphalt screed" (as an existing load distribution layer)! Certainly, what was found beneath the parquet was NOT mastic asphalt. Parquet can indeed be glued onto mastic asphalt, but what the photos show does not correspond to what should have actually been present due to the installation process (laying of the parquet at that time). The old parquet was then laid into a thick hot asphalt layer, which also served as a seal against moisture rising from below. The auxiliary materials used back then often contained PAHs. However, if PAHs were detected in significant amounts in the (black) adhesive layer, it must be removed. And this must be done by a specialist company with the appropriate authorization! Please move away from the topic of mastic asphalt as the basis for discussion. Mastic asphalt was already applied and finished at about 210°C back then. At that temperature, it is impossible to lay parquet; with any adhesive whatsoever?? Furthermore: Mastic asphalt was laid "floating" on a heat-resistant separating layer in residential and commercial construction, just as it is today. If this is not done, the asphalt immediately forms bubbles. These arise because the household moisture contained in the concrete escapes suddenly through the mastic asphalt, which is plastic at approx. 180°C. Therefore, direct application on concrete is not possible. --------------- Greetings to all: KlaRa
