We are considering having a wood burner installed as a secondary heat source in our front room, we live in a rural area, have access to plenty of fuel and no storage problems. Not using it to heat water. However we do have one minor problem.... we have no chimney stack! Previous owners have had it removed down to just above bedroom ceiling. Having it rebuilt will not be a problem, but the question I have is, do we need it lining? There are four fireplaces in the house, two up and two down. We have no intention of ever having fires upstairs and unlikely to have one in the other downstairs room. I welcome the opinions/thoughts/suggestions (polite ones please) of the 'team' . If it has any bearing on the issue the fire would likely only be lit during winter and then only three or four times a week of an evening, in other words, light use. House is a late Victorian terrace with a hideous gas fire in the fireplace, was swept very recently; before gas fire fitted (by previous owners)
If you're having the job done of reconstructing the stack through the loft and the roof then it's absolutely worth having the chimney lined at the same time.
Chimneys have a tendency to crack over time which means smoke and tar deposit leak into the rooms, causing a smell and making stains behind plaster.
The other advantages are that it'll probably draw better and it'll stay clean longer and be easier to sweep.
From a building regulations point of view, it *may* not be required to line the chimney - if putting it back into use is considered a repair.
If OTOH it's regarded as disused, building regs would I think apply.
However there's several reasons why it's a good idea to line regardless.
Stainless steel liners for solid fuel are far from cheap - think about costs being similar to a good quality stove (also don't be misled by the price for linings for gas boilers - they're much cheaper but unsuitable for solid fuel).
However if you're having the chimney stack rebuilt, that's the ideal time to have a liner put in. It isn't unusual to have to at least have to take the pot off anyway, and often the flaunching requires repair.
Other important stuff is the chimney is well designed to draw well and avoid downdraughts - which depends on a myriad of things, surrounding terrain/buildings/trees, shape of your roof, height of chimney above roof - some of which may have changed since the original build.
A liner helps the stove to draw well, which reduces sooting and improves rapid heat-up (reducing the chances and consequences of a chimney fire - which can be bloody scary) - and in some cases may be important for safety.
Ideally you want to get a look at the state of the masonry inside the chimney. The combination of many years of usage/sooting along with rainwater can lead to considerable mortar erosion - in which case definitely don't skip the liner.
If the chimney is significantly larger than the liner, filling the space between with vermiculite is common practice.
Take Christmas as an opportunity to stuff smaller relatives up the chimney for closer inspection.
If you have a woodburning stove then need to have a stainless steel flexible flue flue of the correct diameter to go with it (I guess this is what you mean by lining) otherwise it will not draw properly. I think the question should be: do you need to re-build the stack or is there a cheaper way of venting the fumes?
Two downsides I can see, would look odd on a Victorian house, and would require some rather good lead flashing to make a good seal around a non-standard roof penetration (i.e. you can't use a standard lead slate, nor can you cut and tuck lead sheeting into the brickwork).
OTOH it must be done routinely where these pass through roofs (rather than through walls) where there is no chimney to use at all. I haven't seen the detail of how that is usually done though.
For that matter, if the stack has been taken below slate/tile level - it will still require someone with the art of leadwork to make good around a brick chimney.
It is. Installation of a stove is a 'material change' and the flue MUST be to spec. That means these days LINED. open fires you can get away with, stoves not.
And generally a Bad Idea for a wood stove. Use solid insulated double walled STAINLESS STEEL. Aluminium corrugated will not survive a chimney fire, or even a good roaring fire.
I
It is permissible to take a stainless steel flue straight through a timber framed roof with no stack whatsoever. Just a pipe sticking up,
In message , " snipped-for-privacy@gglz.com" writes
I have done that! Surprisingly easy. Once you know the roof pitch and the brick gauge, each section of stepped flashing can be made up on the bench and then carried up to the roof.
I've been following this thread with interest, as I am thinking of installing a wood stove in a Victorian cottage, which surprisingly has a chimney stack in the middle of the main room. (The cottage was originally the wash-house for a neighbouring orphanage.)
Would I have to line the existing chimney up to the roof? Surely it should not get very hot except close to the stove, or the heat-loss would be very large?
Timothy Murphy wibbled on Thursday 10 December 2009 13:17
Doesn't the requirement of a flue line have something to do with ensuring sufficient draw on the fire? Here's what my instructions say for a 4.5kW ish stove:
"If connecting to an existing chimney with a flue diameter of more than 150mm it is necessary to line the flue using a suitable stainless steel flue liner."
there;s loads on here from a while back about this perennial favourite
- including some by me.
In essence you will be loads better off lining the lot - easier to do and sweep properly, better draw, you do not want to risk your crumbly old masonry leaking flue gases... or being attacked by combustion products (esp from stoves) and becoming leaky (gases or rain)....
in any case how would you sweep a partially lined flue??
it's not just about heat tho is it? your stove should be regulating the amount of air entering it and thus the amount of hot gases going up the flue
As for the OP "modern" flue pipes can look OK. could you send it out the wall at ceiling height then work it up outside - even easier cleaning but not if you're in a terrace.....
But regulations are regulations, and there are reasons.
The most pressing being that wood burners get very hot, and also that they can and do produce tarry deposits which make a chimney fire very likely at some point.
That's when the WHOLE flue gets red hot. And tats why the modern regulations for a new installation insist on double skinned insulated flue designs.
Round here, teh classic chimney fire that burns a house down happens because:
- internal pointing fails, and red hot gases leak into the roof space igniting timberwork
- thatched rooves get set alight by settling red hot ash particles
- the flue itself simply gets red hot and ignites any timber attached to it.
I had a rather special interest in this, having watched my wife's sister's house burn down and being about to build a thatched house, and having the local volunteer fireman as a casual friend.
Oil and gas are less a problem: they dont have such a wide variation of flue temperatures, and the fuel is clean enough to not leave tars.
On my open fires, I had to provide outer brick and line that with ceramic flue liners. And build the stacks up WAY above the thatch, and decouple any wood work from the flue structure with fireporoof board.
On the other double stack, which has an Aga and a wood burning stove, I had been told, erroneously, that only flexible lining was needed inside a blockwork stack. This proved to be wrong: New builds must have either ceramic block lined flues, which I THINK is permissible for a wood stove, or better, double steel insulated flues. In which case the blockwork stack itself was totally redundant and mere 'decoration'
I do know the aga flue is much less expensive and to much lower spec. Its the wood and coal that need the really heavy duty fire proofing.
Oh, and I have set chimneys alight on 5 occasions now..not here, yet, but elsewhere. I can assure you that the temperature and rate of combustion are frighteningly high.
Its a lot easier to do than you think.
So, that's my assesment of the risks, and the reasons for the regulations.
I would say that unless ou have a flue in good condition all the way up, and pre 1967, don't mess with a flexible liner. If part of the flue has been removed, or the build is newer, you will almost certainly be required to fit a double skinned insulated flue anyway, and you might as well take it all the way up and simply leave whatever stacks you have as decoration.
And not get hit by the insurance company if the place catches fire. They tend not to pay up on properties that don't comply with regulations.
My recent experience of all this suggests you might just as well go down the local fireplace shop and pay a silly price for the whole installation. HETAS registered engineers are the only people allowed to install flues, and they all seem to be owners of fireplace shops.
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