- Thread starter robgil
- Start date
With regard to flue sizes, if you plan to go much larger than the standard 5" and 6" sizes do bear in mind that they become increasingly less flexible. We bought a short test section of 10" when thinking of lining our existing chimney for an open fire but realised that there was no way it could be fed into the chimney. The supplier also told me when I subsequently asked about the coiled size that it doesn't come coiled! So for our 11m requirement would have been near impossible to fit without an enormous crane lifting it above the house.
Since then we have gone the woodburning stove route with a self installed 6" liner. Haven't looked back since, it's transformed our lives, can't recommend it enough
Since then we have gone the woodburning stove route with a self installed 6" liner. Haven't looked back since, it's transformed our lives, can't recommend it enough
Penners
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I agree with 'Marm. Any inglenook with a passable "draw" will always suck lots of heat up the chimney. If you install a liner with a canopy, I suspect that you may risk (note the may)increasing the draw, and thus the heat loss.
I also have a small concern about your thatch A liner (insulated or not) could tend to keep the flue gases hotter, higher up the chimney. That being the case, I have an inexpert suspicion that any glowing sparks that ascend the chimney might still be glowing when they emerge at the top.
OK - received wisdom suggests that most thatch fires start inside the roof, rather than outside, and I may be talking utter rubbish (I've been known to do this very occasionally
), but in your shoes I think I would be seeking some knowledgeable views on the whole idea.
A properly qualified chimney sweep and/or your local fire prevention officer might give you useful advice.
I also have a small concern about your thatch A liner (insulated or not) could tend to keep the flue gases hotter, higher up the chimney. That being the case, I have an inexpert suspicion that any glowing sparks that ascend the chimney might still be glowing when they emerge at the top.
OK - received wisdom suggests that most thatch fires start inside the roof, rather than outside, and I may be talking utter rubbish (I've been known to do this very occasionally
), but in your shoes I think I would be seeking some knowledgeable views on the whole idea.A properly qualified chimney sweep and/or your local fire prevention officer might give you useful advice.
christianb
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Actually, Penners, that's a good point. The woodburner I've got in the lounge rattles sparks up the chimney so fast that I've actually had passers-by knock on the door and tell me they think I've got a chimney fire.
Mind you, my local is a thatched 15th century place and they run their open fires pretty much ten months of the year. So far, no 999. I guess thatch tends to have a residual moisture once its been up for a while and is probably pretty resilient to sparks.
C
Mind you, my local is a thatched 15th century place and they run their open fires pretty much ten months of the year. So far, no 999. I guess thatch tends to have a residual moisture once its been up for a while and is probably pretty resilient to sparks.
C
so perhaps i should try to keep the draw to a minimum without totally stopping the fire from lighting altogether? it will be an occasional thing this fire lighting so i am not really worried about heat loss too much. i agree Penners , a chimney sweep is a good idea and one will be employed to check things over along with a building inspector to look over and advise on the liner so hopefully i will be able to cover it all. i have read that insulating the liner one to two meters above the canopy or register plate will keep the heat in the lower parts of the flue creating a draw whilst allowing sparks to dwindle as they pass up through the cooler , un insulated parts above. but i guess every chimney is different and until i get a sweep or flue guy out to have a look i wont know for sure what plan of attack to follow.
chuckey
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The sparks that you intend to let dwindle are actually little bits of burning material. If they do not get consumed by burning freely they will be deposited on the inside of your flue liner and one day may all catch fire. It is considered good practise for stainless steel flue liners to be insulated for their full length (tho' not often done) - it preserves the life of the liner. If the flue is not running hot enough, acidic products of the combustion process condense on the inside of the flue leading to mortar rot and smoke in the loft or corroded out metal flues.
As you are fitting a canopy, why not have a flap constructed that hinges at its top end just behind where the canopy is with two fixing points/clips WHY, one behind the canopy, (flue open for a fire) and one on the rear wall, so the flap can be swung rearwards and upwards to seal the flue and be kept in that position to minimise draugths.
Frank
As you are fitting a canopy, why not have a flap constructed that hinges at its top end just behind where the canopy is with two fixing points/clips WHY, one behind the canopy, (flue open for a fire) and one on the rear wall, so the flap can be swung rearwards and upwards to seal the flue and be kept in that position to minimise draugths.
Frank
Ushy M
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Sorry, late in responding as usual, but just catching up. We have a thatched cottage with two fireplaces, one open and one with a woodburnng stove we had fitted. The advice we had was broadly as follows:
The main risk of fire comes from inside the roof rather than outside as Penners suggests, so it is important to ensure that the liner is insulated as it goes through the thatch (Rockwool sleeving or Chimwrap), though I take Franks' point that lining the whole length is probably not a bad idea.
As far as the risks of sparks igniting the outer surface of the thatch is concerned, it's important to ensure that the top of the stack is at least 5' from the thatch and ensure you're burning good seasoned wood and avoid timber (such as leylandii etc) that generates a lot of sparks. You can also have a spark arrestor fitted, although opinion is divided among insurers as to whether these are a good idea (ours doesn't like them) as they need regular maintenance or they become clogged and can add to the risk.
You're definitely right to seek advice from an experienced sweep. We had our chimneys looked at when we first moved in by someone who assured us they were fine. Some months later as we happened to be outside looking up at the unlined chimney we noticed smoke leaking out through the thatch, and dashed in to put the fire out. We had the chimney repaired and partly rebuilt with lots of pargetting - we could see where the thatch had started to char :shock: It's been fine ever since. We use a different sweep now who sweeps twice a year.
As far as chimney balloons go, we use an old pilow in a bin liner with a very bright pink ribbon attached to it that hangs down so you can see VERY clearly that it's in place!
The main risk of fire comes from inside the roof rather than outside as Penners suggests, so it is important to ensure that the liner is insulated as it goes through the thatch (Rockwool sleeving or Chimwrap), though I take Franks' point that lining the whole length is probably not a bad idea.
As far as the risks of sparks igniting the outer surface of the thatch is concerned, it's important to ensure that the top of the stack is at least 5' from the thatch and ensure you're burning good seasoned wood and avoid timber (such as leylandii etc) that generates a lot of sparks. You can also have a spark arrestor fitted, although opinion is divided among insurers as to whether these are a good idea (ours doesn't like them) as they need regular maintenance or they become clogged and can add to the risk.
You're definitely right to seek advice from an experienced sweep. We had our chimneys looked at when we first moved in by someone who assured us they were fine. Some months later as we happened to be outside looking up at the unlined chimney we noticed smoke leaking out through the thatch, and dashed in to put the fire out. We had the chimney repaired and partly rebuilt with lots of pargetting - we could see where the thatch had started to char :shock: It's been fine ever since. We use a different sweep now who sweeps twice a year.
As far as chimney balloons go, we use an old pilow in a bin liner with a very bright pink ribbon attached to it that hangs down so you can see VERY clearly that it's in place!
biffvernon
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skier-hughes said:Send the wife up like I do
christianb said:
I'm not sure that my wife loves slating
Pipes and rads?robgil said:
And LOTS and LOTS of carbon dioxide goes up the chimney and heats up the ENTIRE planet.Schoolmarm said:
(Some folk ignore all sensible advice about flue liners and live the life of an outlaw, and live to tell the tale.)
I would get a couple of professional HEATAS accredited quotes for lining the chimney - shouldn't cost any more than time and you'll have a good idea of what is recommended.
I would very much recommend a stove over an open fire - more control, better efficiency and fewer draughts when not in use - though it will surely depend on your home if it 'fits'.
I would also check your insurance carefully before you do anything else. My parents have been having fun and games getting buildings insurance on a thatched roof with an open fire - using an unlined chimney for open fires would almost certainly cause problems if you had to claim.
I would very much recommend a stove over an open fire - more control, better efficiency and fewer draughts when not in use - though it will surely depend on your home if it 'fits'.
I would also check your insurance carefully before you do anything else. My parents have been having fun and games getting buildings insurance on a thatched roof with an open fire - using an unlined chimney for open fires would almost certainly cause problems if you had to claim.
Ushy M
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We had no dificulty getting insurance from NFU Mutual on our thatched house (one lined chimney with woodburning stove and one open unlined fireplace). The policy stipulates that you comply with their Thatch Property warranty which states that "all chimneys to solid fuel stoves, boilers and open fires are kept in a good state of reparir and are professionally cleaned at least once a year prior to winter use".
"...vital principles that should be observed in the design of any fireplace. One of these is the relation between the size of the opening into the room and the size of the flue itself. A cross-section of the flue—which incidentally should be kept the same throughout its extent—should be one-tenth of the area of the opening into the room. "
http://www.gutenberg.org/files/26670/26670-h/26670-h.htm#Page_11
I've found a couple of other references to similar ratios, I'll have a dig around.
http://www.gutenberg.org/files/26670/26670-h/26670-h.htm#Page_11
I've found a couple of other references to similar ratios, I'll have a dig around.
Thanks Delta, we might not be lining it now. :shock:
we got a guy out to inspect the Victorian chimney at one end of the house and he said it is fine , he also said there is no legal obligation to line a chimney for an open fire so the insurance company should be ok with it, i checked and we are insured to light open fires in an un-lined chimney so long as we got this cert to say it was ok. we will do all the pointing both inside and out and if i am totally satisfied ive got it all then bish bash bosh, toasted marshmallows.
we got a guy out to inspect the Victorian chimney at one end of the house and he said it is fine , he also said there is no legal obligation to line a chimney for an open fire so the insurance company should be ok with it, i checked and we are insured to light open fires in an un-lined chimney so long as we got this cert to say it was ok. we will do all the pointing both inside and out and if i am totally satisfied ive got it all then bish bash bosh, toasted marshmallows.