sealing around flue

[yamahamark]

Hi guys

Eon recently serviced system boiler located in converted garage now a room.
Flue got damaged during renovation but replaced by gas safe engineer, however the whole around it wasnt sealed so you can feel a draft from the wall cavity.

I need to seal the whole around the flue pipe, so can i use expanding foam or does it have to be mortar?

Thanks

 

[Destroyer2813]

Just use sand a d cement its what I always use

 

[yamahamark]

Yeah was just thinking foam quicker, easier and less mess.

Looks like i'll do what you suggested although its a bit awkward getting in with a trowel.

Thanks for your reply

 

[novicegas]

if you do use exp foam get the pink fire rated stuff.

 

[Whyme]

Carefull using too much foam cos it will spew everywhere when it expands.

 

[yamahamark]

Can i take it theres no issue or gas reg restricting use of foam as dont want eon moaning at next service.

I have used this stuff before on the odd occasion so understand not to squirt too much out!

 

[Guest123]

Should have a fire guard plate and sealed with intumescent fire cement.

 

[kozak1968]

Vaillant say mastic is acceptable to seal around the flue.

 

[villa_tom]

I wouldn't use expanding foam. I once saw a flue sealed with expanding foam and the foam warped and disturbed the flue joint. Admittidly the joint was screwed but still it wasn't a pretty site.

 

[AWheating]

any suitable seal that meets the fire rating of the wall and the manufacturers instructions should be fine. Sand a cement is the best option really, easy to mess with in the future also when you have a new boiler.

 

[yamahamark]

Ok thanks.

Just got some sand cement mix, little job for tomorrow.

 

[AWheating]

if the gaps quite big then use some fibreglass out ya loft to pack it out alittle first. If its a condensing boiler make sure it has a slighty rise to outside, if its a standard non condensing boiler its best to be level or have a slight fall.

also patch it up with the boiler turned off.

 

[yamahamark]

if the gaps quite big then use some fibreglass out ya loft to pack it out alittle first. If its a condensing boiler make sure it has a slighty rise to outside, if its a standard non condensing boiler its best to be level or have a slight fall.

also patch it up with the boiler turned off.

Good advice thanks as the hole is a right mess as core drill not used so the brick is a mess.

 

[hammers4spanner]

Blimey

 

[yamahamark]

Photo of flue, this was all boxed in and screws were filled over and painted. So once done i'll make sure the panel will be easily removable for inspection.

 

[jase158]

get engineer back, get him to seal it!!

 

[Whyme]

hahaha thats a gud one i love pics. sand and cement like the guys say but fire rated foam aint illigal as far as i know ( please quote bs if im wrong or edit post mods), as long as no fumes come back in and the filling substance has a fire rating.

 

[yamahamark]

Suppose it would have been better to post photo earlier, however as new to forum i have only just found out how to do it.

 

[Dotty]

Never too late fella. I'd have the installer back as making good is part of the job......

 

[tamz]

Total shyte job. Don't want to worry you but if he left that what else has he left. Maybe down to the money.

 

[Whyme]

looks like he used a breaker to knock that flue hole out.

 

[acecharly]

Someone give him doms phone number so we can watch this muppet on tv.

 

[yamahamark]

All done now, thanks for the advice.

 

[oily-rag]

I would point the hole up with a mortar mix.

 

[yamahamark]

The hole is filled With mortar? Cant really fill any more as i would be covering The join between flue pipe and 90deg bend.