I have recently moved into a house, where there is a large gap around the combi flue (i.e hole has been made, but never finished off). Can I used expanding foam to fill this gap, or do I need to use mortar?
can I used expanding foam round a combi flue?
Feb 20, 2007
4 Replies
You can, but I'd use mortar. If you do as you plan you really need to cover it with something such as a trim ring. PU Foam is not UV stabilised and will deteriorate in the sun. It is also soft and hardly a great external finishing material.
Maybe the OP meant on the internal wall.?
On the internal wall I always use one-coat plaster. Foam would look terrible and risk over-expanding and spilling into the boiler.
Likewise I use mortar (sand & cement mix from the sheds) for outside.
But my reply was in response to
"You can, but I'd use mortar. If you do as you plan you really need to cover it with something such as a trim ring. PU Foam is not UV stabilised and will deteriorate in the sun. It is also soft and hardly a great external finishing material."
Join the Discussion
Have something to add? Share your thoughts — no account required.
Didn't find your answer?
Ask the community — no account required