Seal bathroom sink drain to vanity/wall

Question

I'd like to seal the hole in the wall/vanity where the drain goes to. I assume there is some sort of circle cap that I could glue there.

The reason is that I feel a current of air going out of there. I am in the 4th/top floor of an small building, sometimes the air smells. I believe there is a chimney effect bringing air from the lower floors to mine.

Note: I know that's not the only crack/opening able of transporting air, however, I am just following the smell. It is faint (almost nobody else notices) so maybe if close the big holes that I can see it will go undetectable.

Please advise. thanks.

Answer 1

You are correct that there is trim made for this, but if you've never seen one the term for it is hard to figure out... It's called a pipe escutcheon and they come in two flavors.

If you can disconnect the pipe and slip the pipe escutcheon over the end, the single piece models look better and will seal better. If you don't want to mess with the pipe, they also come in a "split" ring that is either two pieces, or more commonly, a hinged ring that opens up to fit around the pipe and then close back around it.

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Answer 2

This is the waste drain vent penetration through the cabinet which would lead into the wall where it would join up with both the vent going to the roof and the drain that likely goes down and hooks into other bathrooms that are stacked below yours.

For air sealing, I'd use air sealing tape. tescon-vana blue air sealing tape or if you want to go cheap you could just use tucktape and just tape the cabinet to the pipe. It won't look great but this is under your cabinet. If you get the escutcheon you'd have to caulk around both the outside and the inside to do a decent job air sealing.