Sealing around flues

[moony]

What's the classification for sealing around flues (AR, ID, NCS)

Had a discussion, with landlord - if it's sealed outside and not inside, what would you say it is?
And if it's not sealed at all only using rubber surround ?

Thanks

 

[Billy Bob Bob]

if its well sealed on the outside fumes cant come in,if its just the rubber grommet i have 2 issues fumes coming back in and flues coming apart if they are not secured with screws modern HE boilers tend to be push fit so can be susceptible to coming apart especially if a fault develops,so if its not sealed its AR the rubber grommet/tidy they give is just that its not a

 

[moony]

So if it's sealed outside with mortar but not inside - you would be ok with that ?

I normally just seal them up inside and add a tenner to cost of cp12....

Now first LandLord I've had say its not required as it was sealed outside with cement - I was wondering if it's now required - whenever we fit boilers we seal outside and in. and I was under impression it was at least NCS if only sealed outside. He even argued that a rubber grommet is enough - I said definately not it would be AR. And if there was no grommet and no cement seal then it could even be ID? Am I right or wrong I've looked through books etc and think I'm right but some opinions would be grateful. As he is looking it up also.

 

[kirkgas]

i have seen MI's which say the grommet is enough and can be used to seal the flue from the inside by drilling a larger hole and pushing the grommet through from the outside, so if its in the MI its fine, check specific for boiler, if sealed on the outside and not inside its not even NCS, although it doesnt look great

 

[mountainman]

i have seen MI's which say the grommet is enough and can be used to seal the flue from the inside by drilling a larger hole and pushing the grommet through from the outside, so if its in the MI its fine, check specific for boiler, if sealed on the outside and not inside its not even NCS, although it doesnt look great

I've seen the same but I had an unpleasant encounter the other day.

Called out because BG had disced meter following a smell if gas.
Condensing boiler fitted in former garage of town house, garage now converted into bedroom.
Flue drilled through wall into outside cupboard, two 135deg bends then drilled through to outside.
No cement sealant only rubber seal out side and one between cupboard and bedroom.
The flue had disconnected in the cupboard and was leaking POC into cupboard and bedroom.
Fortunately there were no injuries or worse.

Half a bucket of sand and cement and ten minutes work would have prevented POC from entering the bedroom.

MI's aren't gospel IMO.

 

[tamz]

There are many manu's who allow only sealed with the rubber collar. It is up to you to find it out or use your judgement.

If the flue was sticking 2ft out the wall with no seal inside or out how would you class that apart from an eyesore as technically it is ok.

 

[tamz]

MI's aren't gospel IMO.

Thats true but no one wants to use their brain any more so unless it is written down they can't and won't do it.

 

[mountainman]

Just as well there are old duffers like thee and me still around to impart some common sense occasionally then eh!

 

[GrahamM]

This is a case when the MI's need to be read in conjunction with the British Standards.
The standards require the flue annular space to be sealed.

 

[moony]

I don't think it's a case of being idle and not using common sense. Just a case of covering yourself.

I tend to go with what's in my head - I'm not exactly a book follower but i know if something is safe or not. It's just when I charge for something and someone says it wasn't required then that's when I start to question it, and try and justify the work I done and back it up with regs.

Just seems a grey area....

 

[AWheating]

patching the inside only is fine if the manufacture states the rubber seal is exceptable, but i would always patch the outside. Theres also the issue of possible damp in the wall if the rubber seal is not watertight.