I am living in a multi-family house which happens to be an old building. The person living under my room is a chain smoker. Unfortunately, the smoke is smellable in my room, even if I close the window and the doors. The only direct connection beween our flats is the heating pipe passage way.
Now the passage way was proofed with silicone. I wanted to renew the silicon because I thought this might help.
What is this stuff inside that looks like loose wool? Should I replace it with something before I put silicone on it? Any ideas how can improve the proofing so that almost no smoke will pass through?