Cold draft from roof lanterns

Cold draft from roof lanterns

Author
Discussion

snowman99

Original Poster:

400 posts

146 months

Wednesday 26th February 2020
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We have an flat roof extension with two lanterns and an external flue for a wood burner. It was only finished last year. I’ve noticed a cold draft from the lanterns and flue. The flue draft was solved by filling the cavity above the stove with rock wool (it’s a warm roof). However the draft from the lanterns is still there slightly.

I can’t tell if the draft is getting in via the lanterns - I can’t see any obvious gap. Or it is coming in vi the lead flashing around the flue and then moving through the roof and exiting into the room via the lanterns.

I could seal up the gap between the plasterboard and the lantern glass? And/or seal around the lead flashing but I don’t see people doing this. Any ideas? The problem goes away when the wood burner is on rather than the radiator but it’s a bit annoying.








Simpo Two

85,149 posts

264 months

Wednesday 26th February 2020
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I'd suggest it's convection, a simple downdraught of cooler air because the glass leaks heat more than the rest of the roof.

Alucidnation

16,810 posts

169 months

Wednesday 26th February 2020
quotequote all
snowman99 said:
We have an flat roof extension with two lanterns and an external flue for a wood burner. It was only finished last year. I’ve noticed a cold draft from the lanterns and flue. The flue draft was solved by filling the cavity above the stove with rock wool (it’s a warm roof). However the draft from the lanterns is still there slightly.

I can’t tell if the draft is getting in via the lanterns - I can’t see any obvious gap. Or it is coming in vi the lead flashing around the flue and then moving through the roof and exiting into the room via the lanterns.

I could seal up the gap between the plasterboard and the lantern glass? And/or seal around the lead flashing but I don’t see people doing this. Any ideas? The problem goes away when the wood burner is on rather than the radiator but it’s a bit annoying.







I might be missing something, but all of that looks like an impressive bodge to me.

Pothole

34,367 posts

281 months

Wednesday 26th February 2020
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Any chance of some even smaller, crappier pictures?

lj04

371 posts

190 months

Wednesday 26th February 2020
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That is a total bodge. That isn't a legal outlet for a wood burner and they have stuck a cold frame on your roof.

Alucidnation

16,810 posts

169 months

Wednesday 26th February 2020
quotequote all
The pics in the OP are bigger if you click on those.

mintybiscuit

2,811 posts

144 months

Wednesday 26th February 2020
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Pothole said:
Any chance of some even smaller, crappier pictures?
Why do you always have to be a tt ?

You have been here long enough to know how to click on an image to enlarge !

moles

1,794 posts

243 months

Wednesday 26th February 2020
quotequote all
The wood burner outlet pictured is just the lead cowl ain’t it over the upstand?, it’s got a longer pipe with a mesh type terminal I take it?.

Aluminati

2,475 posts

57 months

Wednesday 26th February 2020
quotequote all
Alucidnation said:
I might be missing something, but all of that looks like an impressive bodge to me.
Correct !

snowman99

Original Poster:

400 posts

146 months

Wednesday 26th February 2020
quotequote all
moles said:
The wood burner outlet pictured is just the lead cowl ain’t it over the upstand?, it’s got a longer pipe with a mesh type terminal I take it?.
There is definitely a pipe of some sort under the lead up stand-I remember when it was installed. I can’t expose that now though. The lead goes to an upside down cone then twin wall flue which goes up a few metres more out of the pictures.

Edited by snowman99 on Wednesday 26th February 19:19

Pothole

34,367 posts

281 months

Thursday 27th February 2020
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mintybiscuit said:
Pothole said:
Any chance of some even smaller, crappier pictures?
Why do you always have to be a tt ?

You have been here long enough to know how to click on an image to enlarge !
Ooh, hello stalker.

I made an error. I never hold myself up as perfect. (I try not to call people names, too. Give that a go)

OP, that lead flashing looks awful. I'm not a builder, I'm not even very good at DIY. I'd be ashamed to have done a job that looked like that...

E92M3STEVE

80 posts

125 months

Thursday 27th February 2020
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How funny, sat in our flat roof extension that has a 4m x 2m lantern moaning about the draft.

Only really notice it when cold outside, the roof is new and no issues.

Had it done as heat loss.