ᐅ Sealing the voids beneath the foundation slab pipes

Hello everyone,

We are building a house using wood frame construction. Under the walls where the pipes connect to the floor slab drains, the installation company removed the swelling mortar and carried out the installation. Afterwards, the rising pipes were wrapped with the connection strips from Katja Sprint (but not in one piece—rather in segments—due to space constraints, as the walls were already closed up again).

Now the question is whether the area around the pipes, basically the cavities, can remain as they are or if they need to be filled.

If so, with what? There is no swelling mortar left. Expanding foam?

Next week, the underfloor heating will be installed, followed by the screed. So these areas will be within the insulation but essentially remain as small cavities between the floor slab and the wall.

Hope this makes some sense.

Thanks a lot for your help!

Best regards from the night shift

Sky