Insider secrets # 11
Check Your Pipes – “Out Of Sight” Should Not Mean “Out Of Mind”
Traditionally the “household way” is to stuff the gap with steel wool to keep out rodents. This is mildly effective in terms of draught-proofing but it does tend to rust of time.
A better way to seal these pipe penetration gaps is with a sealant. For a smaller hole, I’d suggest HB Fullers Ultraclear (also known as Fulaseal). It is very easy to use and you can clean it up with water. But for massive holes, you need something more flexible, so I would suggest silicone. Silicone can be used with a silicone spreader, which is not very expensive, and you can clean up with some tissues or newspaper.