ᐅ What is the fleece layer under the carpet? – Older building

Hello everyone,

I am currently planning the renovation of my attic. It was originally converted in 1973 (previously an expansion reserve) and modified again in 1992.

The entire floor is covered with the same carpet (I’m not sure whether it dates back to the original conversion or from ’92). I want to replace it now with something more modern. Yesterday, I peeled back a corner to estimate how much work this will involve. As expected, it’s fully glued down.

What puzzles me, however, is the structure: beneath the carpet, there is a layer of crumbly material – which seems to be some kind of old underlay – and then a fleece made of fine, white-gray fibers. When I pulled it up, the fleece came off easily together with the carpet from the floor, but the delicate fiber structure makes me uneasy.

Since there are already safety concerns because of old mineral wool and “angel hair” insulation in the attic, I wonder if this could be a potentially hazardous material? Has anyone come across this kind of material and can advise how to handle it properly?

I would appreciate any suggestions or advice,
Yours, schwenkgrill

The fleece is part of the backing layer of the carpet. This is how carpet used to be manufactured. The "crumb layer" provided stability, acted as impact sound insulation, and primarily prevented the carpet from slipping. Over time, the plasticizer breaks down, leaving behind these crumbs. However, this should not cause any issues. When removing it, make sure there is good ventilation, and if you are particularly sensitive, you can buy a dust mask at a hardware store.

Thank you for your assessment. We removed the carpet today without any major problems. The air wasn’t too thick afterwards, but we were wearing overalls and respiratory protection anyway. Since we also removed the substructure at the same time (old particle boards), the complete removal was not an issue. Whatever came off with the carpet stayed on the carpet, and whatever stuck to the substructure just stayed stuck.

I’m just glad that this chapter is now finished.