Expanding Foam - quick question

Realtine

Guys when our gas boiler was installed the pipe from same obviously protrudes
through to the outside wall. Well the guy that installed it never filled that hole and it's quite gappy and unsightly and cold even though it's shielded on the inside into a press.
Anyway what I want to know is if expanding foam can be used to fill the hole on the outside around that pipe (don't know what's it's called) - and then use cement to smooth over it.

(can't seem to use cement at the moment as it just falls down into wall)

Himself's not very handy but it seems a simple enough job. he's worried about the foam being a fire hazard.
so just asking..

thanks,

aujopimur

Regular foam is ok, you can use intrumesent foam if you like.

Joey the lips

I am guessing you mean the 4 inch white flue pipe. Yes foam will be fine. It does not need to be fire safe as i am sure its a gas twin wall flue.

However a far less messy method would be filler or siliocone. That expanding foam is very very messy and hard to impossible to remove once cured

meercat

dont spray that expanding foam when the boiler is on.it contains butane and i know of a case of it igniting when sealing around flue.try filling hole with fibreglass or something non flamable and fill with sand/cement