Expanding foam around hot pipes?

[niftyprose]

Hello guys, an easy one: I recently had to drill through two outside walls to run 15mm pipes for a shower and sink. The holes are neat enough but need to be closed off to prevent draughts. Can I use expanding foam to block them? I wouldn't do this with central heating pipes, but the shower and sink are only seeing a few minutes' use each day. Best, NP

 

[ShaunCorbs]

Yes just insulate the pipes