Flue terminal too close to roof?

[Dave1974]

Good afternoon,

 

I’ve recently had a wood burner installed by a HETAS registered company but the flue terminal seems too close to the roof.

 

When I was getting quotes I was told the terminal would need  to extend 1000mm above the roof but it’s only around 200-300mm as per the pics.

 

Im a gas safe registered engineer so understand about the importance of clearances the ensure a good pull but just wanted to check with others in the stove world as I know clearances etc are different & as to whether I need to bring it up with the installer 

 

Thanks

 

[MJNewton]

I think Diagram 17 of Approved Document J is relevant - or least helpful - here, however your flue doesn't technically pass through the roof as a 'weather surface'... Even so, I would expect it to be following the principles relating to being within 2300mm of a window (in which case it should be 1000mm higher than the top of it) or being within 2300mm of a building (in which case is should be 600mm above the highest part within that 2300mm). Hard to tell from the photos but is it within 600mm of the ridge too? If so, I would expect it to be following the rule about needing to be 600mm higher than it just as it would need to be if poking through the roof at the point. I'm no expert though - just a lay man attempting to interpret the guidance - but I would be expecting one of either 600mm or 1000mm rather than managing to avoid all of these rules entirely by virtue of it not actually poking through the roof as will surely still be similarly affected by it in terms of getting/keeping combustion products out of the building. Be careful what you wish for though as it might be perfectly safe as it is, and look better than if it were to be made taller!

 

Edited September 18, 2020 by MJNewton

[Dave1974]

Thank you for taking the time to reply.

 

No, it’s not within 600mm of the ridge &  going by note 4 on that diagram I also thought it should be 2.3m from the terminal to the roof surface.

 

Personal I don’t mind the looks if the terminal was higher & I would prefer it to comply with the building regulations 

cheers

[Dave1974]

[MJNewton]

12 minutes ago, Dave1974 said:

No, it’s not within 600mm of the ridge &  going by note 4 on that diagram I also thought it should be 2.3m from the terminal to the roof surface.

 

I didn't see Note 4! Good that that's there as it makes your situation clearly covered by it. I'd say it means it should be 600mm above the roof surface though (not 2300mm which I suspect was said in error).

Edited September 18, 2020 by MJNewton

[Dave1974]

I think the 600mm Is part A which only relates if it’s within 600mm of the ridge  which it isn’t, so my understanding is it would come under part B

 

so either 2300mm horizontally or 1000mm higher than the intersection? 
 

Thanks 

[MJNewton]

Sorry, yes, I agree it'd be B and so 1000mm above the surface. I thought you were suggesting/thinking 2300mm above the surface...