Lining chimney for woodburner

[Tancrède]

I am thinking of replacing my woodburning stove.  The previous one, old and inefficient as it is, has worked perfectly well for many years in connection with an unlined chimney.  The flue is swept regularly and and there is no perceptible problem with the escape of either tar or smoke.

The stove is /will be a small one circa 4-5 kw. and, not being

essential to the heating of the house, is not in constant heavy use.

Is there any necessity, either for reasons of prudence or in order to conform with present legal requirements, to have the chimney lined if I have a new stove installed ?

And if such a lining is necessary, can anyone possibly give me a wild estimate as to what sort of cost might be involved in lining a broad and fairly straight 13 metre chimney, please ?

Finally, I was thinking of getting a Morsø.  Is there anything about this choice which would provoke anxiety or resentment in a French chauffagiste ?

I shall be most grateful for any help as I know absolutely nothing about these matters…

[Bill]

I know nothing about french regs,

 

but in the UK   you must have a twin skinned  flue, can be bought as a coil and dropped down from the top of the chimney ,

 

some people insist on then filling the void with something else, but my supplier didnt.

 

on the other chimney , it came in 2 foot segments, which snapped together and were stuffed up from the bottom , giving a rigid  flu

 

Whole point is to stop your chimney catching fire..  still needs sweeping  :(     So then one asks, whats the point ?

 

don't forget if you are up there anyway,  the bird protector for the top , worth its weight ingold.

 

rgds

Bill

 

 

[Théière]

[quote user="Bill"]

Whole point is to stop your chimney catching fire..  still needs sweeping  :(     So then one asks, whats the point ?

[/quote]

It doesn't stop your chimney catching fire, it stops gasses seeping through the brickwork/wall and poisoning you with carbon monoxide and acidic flue gasses from eating your mortar/stonework and bringing the chimney crashing down.

[Bill]

so that's the point  Theiere   :)

 

rgds

Bill

[Bill]

so that's the point  Theiere   :)

thanks

rgds

Bill

[Tancrède]

Thank you for the comments. 

I am still unclear as to whether lining a chimney is now required for the installation of a woodburning stove or not.  If anyone has a link for the current regulations, that would be very much appreciated.

[Théière]

Does it really matter if it is regulation or not, it's better practice and safer for all concerned. [I]

http://www.poujoulat.com/

[John Brown]

Interestingly the Installation Guide/Booklet that came with my Franco Belge "Limousin" Woodburner shows the option of a Flue Pipe going through a Register Plate and no Liner

I took the view that the chimney has, for over 150 years, had to cope with a large open fire discharging into it, so as long as the chimney is good order, which I established by inspecting it internally it can cope with a 6 inch pipe.  

[Tancrède]

[quote user="John Brown"]Interestingly the Installation Guide/Booklet that came with my Franco Belge "Limousin" Woodburner shows the option of a Flue Pipe going through a Register Plate and no Liner[/quote]

Thank you ;   that is my preferred solution unless there is a compelling regulation to the contrary.  May I ask if that is a recent document, please ?

[John Brown]

I ordered the Woodburner off the Internet ( French Supplier ) in August last year and took delivery late September.

The Chimney Sweep who did the pre-clean after the installation give it the thumbs up.

He said a common mistake is to line the flue with solid pipe sections but not line it to the top of the chimney allowing fumes to cascade back down the void and collect above the register plate. It's recommended that the end of the flue pipe does not extend more than 4  inches past the back of the register plate.

 We are on our third Cord of wood this winter and are pleased with the fire. I've fitted smoke and carbon monoxide alarms in the Living Room, Bedroom and the Loft where the chimney passes through.

Hope this helps

[Tancrède]

[quote user="John Brown"]He said a common mistake is to line the flue with solid pipe sections but not line it to the top of the chimney allowing fumes to cascade back down the void and collect above the register plate. It's recommended that the end of the flue pipe does not extend more than 4  inches past the back of the register plate.[/quote]

Thank you.  Yes, that makes sense and precisely reflects the way my present one is fitted. 

I think that this will be my way forward  -  perhaps with the addition of a strategically-placed CO detector.

[Théière]

[quote user="Gengulphus"]
[quote user="John Brown"]Interestingly the Installation Guide/Booklet that came with my Franco Belge "Limousin" Woodburner shows the option of a Flue Pipe going through a Register Plate and no Liner[/quote]
Thank you ;   that is my preferred solution unless there is a compelling regulation to the contrary.  May I ask if that is a recent document, please ?


[/quote]

Depends on the size of the chimney obviously as the bigger the chimney the slower the exit of smoke/gasses etc only real way to test is to see how much it draws and if that is in accordance with the manufacturers instructions. Fitting a liner will ensure a good draw and that extra bit of safety.

[pachapapa]

[quote user="Gengulphus"]
[quote user="John Brown"]He said a common mistake is to line the flue with solid pipe sections but not line it to the top of the chimney allowing fumes to cascade back down the void and collect above the register plate. It's recommended that the end of the flue pipe does not extend more than 4  inches past the back of the register plate.[/quote]
Thank you.  Yes, that makes sense and precisely reflects the way my present one is fitted. 

I think that this will be my way forward  -  perhaps with the addition of a strategically-placed CO detector.


[/quote]

The pipes up chimneys is of more bnenefit to the back pockets of artisans than of any real tangible benefit to the owner of the chimney.

The smaller the conduit the greater the resistance to the flow. It is perfectly obvious that the lowest resistance to the flow of the combustion gases will be by using the conduit of largest cross-sectional area i.e. the chimney. A conduit with a small area and consequentially higher velocities will probably be deleterious to the management of associated suspended solids and tars from the combustion process.

[Tancrède]

[quote user="pachapapa"]The pipes up chimneys is of more benefit to the back pockets of artisans than of any real tangible benefit to the owner of the chimney.[/quote]

Quite.  This is the entire and only reason for this post which seeks  -  before I lock horns with the aimiable chauffagiste  -  to discover if there is now A Regulation to the effect that I should contribute in this particular way to the lining of his pocket. 

If there isn't, then I am happy to continue to use a chimney  -  without metal pipe  -  which has functioned perfectly adequately for several centuries.

[quote user="pachapapa"]It is perfectly obvious that the lowest

resistance to the flow of the combustion gases will be by using the

conduit of largest cross-sectional area i.e. the chimney.[/quote]

I shall adopt the line of Least Resistance.

[pachapapa]

A pôele is OK but an insert is not due to higher temperature.

Got a macif folder somewhere ...will check tomorrow.

A shared conduit is also a no no but most old houses have a single chimney for each fireplace.

However I know of a house in St Loup with a chimney with connections on two separate floors, the problem of avoiding tubage was solved by installing two identical Supra wood stoves effectively preventing any recirculation; possibly not entirely legal but works very well.

[Théière]

[quote user="Gengulphus"]
[quote user="pachapapa"]The pipes up chimneys is of more benefit to the back pockets of artisans than of any real tangible benefit to the owner of the chimney.[/quote]
Quite.  This is the entire and only reason for this post which seeks  -  before I lock horns with the aimiable chauffagiste  -  to discover if there is now A Regulation to the effect that I should contribute in this particular way to the lining of his pocket. 

If there isn't, then I am happy to continue to use a chimney  -  without metal pipe  -  which has functioned perfectly adequately for several centuries.

[quote user="pachapapa"]It is perfectly obvious that the lowest resistance to the flow of the combustion gases will be by using the conduit of largest cross-sectional area i.e. the chimney.[/quote]
I shall adopt the line of Least Resistance.




[/quote]

I really don't agree, this being a forum however you will go with the post which follows your own thought train. The old chimney would have had a simple fire which most of the heat went up the chimney anyway ensuring a high flow rate of smoke and gasses. Altering the design and keeping some of the heat from doing so with a registry plate changes things, the biggest surface area may produce the least restriction but also could provide so much area that the gasses cool too much by the top of the chimney and begin to fall again creating a convection current.  Some of the gasses could be unburnt and in the case of cold fresh air entering from the top could cause a flashover via back draft.

[pachapapa]

[quote user="Théière"]

[quote user="Gengulphus"]
[quote user="pachapapa"]The pipes up chimneys is of more benefit to the back pockets of artisans than of any real tangible benefit to the owner of the chimney.[/quote]
Quite.  This is the entire and only reason for this post which seeks  -  before I lock horns with the aimiable chauffagiste  -  to discover if there is now A Regulation to the effect that I should contribute in this particular way to the lining of his pocket. 

If there isn't, then I am happy to continue to use a chimney  -  without metal pipe  -  which has functioned perfectly adequately for several centuries.

[quote user="pachapapa"]It is perfectly obvious that the lowest resistance to the flow of the combustion gases will be by using the conduit of largest cross-sectional area i.e. the chimney.[/quote]
I shall adopt the line of Least Resistance.




[/quote]

I really don't agree, this being a forum however you will go with the post which follows your own thought train. The old chimney would have had a simple fire which most of the heat went up the chimney anyway ensuring a high flow rate of smoke and gasses. Altering the design and keeping some of the heat from doing so with a registry plate changes things, the biggest surface area may produce the least restriction but also could provide so much area that the gasses cool too much by the top of the chimney and begin to fall again creating a convection current.  Some of the gasses could be unburnt and in the case of cold fresh air entering from the top could cause a flashover via back draft.

[/quote]

Am I correct in assuming that you consider a 22KW Insert as suitable for a simple brick or stone conduit/chimney due to the higher dissipation of heat via the chimney.

[pachapapa]

So in effect the installation of a wood burning stove does not require the lining of the chimney, by the way this is called "tubage/entubage" in french. The proviso is that the chimney is in satisfactory/good condition, it is not leaking or liable to fall down, etc.

It is amazing how many chimneys in old houses such as mine which have had one metre logs roaring in them for three centuries creating such an updraft that the front door has to be opened to supply air; then a stove and installer arrive and surprise, surprise it needs excruciatingly expensive double walled stainless steel tubing.[:D]

Stick you heels in G.

[Bill]

Living in a house which has had open fires for 5 centuries   [blink],  I admit I fell for the U must have a lining line .

next door doesn't,  nor does my friend with  a pretty old house , but he is finding that to use the fire as it was intended is beneficial (with the doors shut in his case )

There are scare stories, many of them in the links below,. (all UK)   it seems not a (UK) regulation, but  reading all of these , it does depend on the state of your chimney as to if u should or shouldn't. .

I must say.. reading all on this link, and all of the links below, I ask my self the question , would I install a liner again? cost 1000 quid ?  mmmmm Yes.  Remember I am with brick chimneys not stone, My lime plaster has to be suspect as I doubt if anyone has taken a look in the past 450 years, I have  huge fireplaces  &  a  good draw,   BUT being stupid in all matters such as this,  I can't be bothered with anything other than safe.  Will I installl a liner in our new house in France ?  Yes.

 

Pachapapa  is right about drawing in the air from the house, some people even  suggest a pipe from outside to the bottom of the fireplace , to draw in air from outside . Our house leaks so much, we didn't !!!  The point being,  why draw in air , that's already heated to expell up a chimney ?   It's for sure a complicated area, or just smoke and mirrors ???  I really don't think its  a fly by the seat of your pants  issue, I know I am not competent hence why I fall the safe line of the question , all be it unnecessarily. 

 

French regs was your question, I don't know..

rgds

Bill

I googled, should I line my chimney and found these.. some  look like scare stories .

http://www.countrystoves.co.uk/whylinechim.htm

http://www.stovesonline.co.uk/why-line-a-chimney.html

http://www.woodburningstoveslimited.com/index.php?action=cms.lining_56

http://www.halnakerstoves.co.uk/chimneys/why-line-chimneys.aspx

http://www.stovesonline.co.uk/stove_building_regulations.html

An existing chimney must firstly be given a visual inspection,and make sure it is of a suitable size,a smoke test should be carried out to make sure it is clear of obstruction and check for gas tightness,your chimney should be swept before installing a new appliance,do not attempt to fit a liner without firstly sweeping the chimney,if your chimney passes the the visual inspection and passes the smoke test,it is deemed sound and not a legal requirement to line,lining your chimney has advantages such as increased draw and better efficiency,reduces the risk of chimney fire,and piece of mind having a sealed system

http://www.pgfireplaces.co.uk/faq.php?action=cms.Multi_Fuel_Stove

 

[Bill]

my french is not good enough ,... but this MIGHT  help

 

http://www.cstb.fr/fileadmin/documents/telechargements/Installation_combustion_juin_OK.pdf

 

http://www.cstb.fr/    then search within this web site.

 

rgds

 

 

 

[pachapapa]

Thye relevant DTU is DTU 24; the section covering poeles, foyers and inserts is DTU 24-2.2.

There is a an 11 page excerpt from the full CTSB guide which has a use ful diagrams.

Here is the link to the excerpt; note that the cheminée uses "boisseaux" sort of square concrete with male female jointing.

I use them for making pillars with rebar and concrete/mortar inside.

http://boutique.cstb.fr/dyn/cstb/upload/fichiers/ext_cheminee.pdf

[Théière]

[quote user="Bill"]

An existing chimney must firstly be given a visual inspection,and make sure it is of a suitable size,a smoke test should be carried out to make sure it is clear of obstruction and check for gas tightness,your chimney should be swept before installing a new appliance,do not attempt to fit a liner without firstly sweeping the chimney,if your chimney passes the the visual inspection and passes the smoke test,it is deemed sound and not a legal requirement to line,lining your chimney has advantages such as increased draw and better efficiency,reduces the risk of chimney fire,and piece of mind having a sealed system

[/quote]

That is pretty much the nuts of the subject Bill.  I was corrected by someone who has been installing in France for years that twin wall (uninsulated) is not yet a requirement even for wood burners so single skin would do. In the UK HETAS only recommend single skin for gas burning flues, wood burning should be twin walled but by now you have probably noticed that in your links etc. Most of the wood burners if not all have the single skin and have been going 15-16 years.  I think the points I made are echoed in the links you have supplied so the final choice is yours.

The UK again recommends wood burners of more than 10kw must have an air supply into the room as the fire will draw in the air to combust and as air is 80% nitrogen 20% oxygen you can see that oxygen depletion is quite easy and so is slipping in to a coma, thankfully rare due to leaky old buildings and our inbuilt sense of stuffy air open the door/window. Likewise slipping into a coma after reading posts from PPP [:)]

[quote user="pachapapa"]

It is amazing how many chimneys in old houses such as mine which have had one metre logs roaring in them for three centuries creating such an updraft that the front door has to be opened to supply air; then a stove and installer arrive and surprise, surprise it needs excruciatingly expensive double walled stainless steel tubing.[:D]

[/quote]

Despite this bloke allegedly having a degree in engineering related matters it seems amazing that they haven't grasped the basic understanding of why a roaring open fire is different to a stove so the chimney/flue designs are different even though your links describe it very well. (open fire 95% of the heat rises up the chimney taking the gasses with it)

[pachapapa]

[quote user="Théière"][quote user="Bill"]

An existing chimney must firstly be given a visual inspection,and make sure it is of a suitable size,a smoke test should be carried out to make sure it is clear of obstruction and check for gas tightness,your chimney should be swept before installing a new appliance,do not attempt to fit a liner without firstly sweeping the chimney,if your chimney passes the the visual inspection and passes the smoke test,it is deemed sound and not a legal requirement to line,lining your chimney has advantages such as increased draw and better efficiency,reduces the risk of chimney fire,and piece of mind having a sealed system

[/quote]

That is pretty much the nuts of the subject Bill.  I was corrected by someone who has been installing in France for years that twin wall (uninsulated) is not yet a requirement even for wood burners so single skin would do. In the UK HETAS only recommend single skin for gas burning flues, wood burning should be twin walled but by now you have probably noticed that in your links etc. Most of the wood burners if not all have the single skin and have been going 15-16 years.  I think the points I made are echoed in the links you have supplied so the final choice is yours.

The UK again recommends wood burners of more than 10kw must have an air supply into the room as the fire will draw in the air to combust and as air is 80% nitrogen 20% oxygen you can see that oxygen depletion is quite easy and so is slipping in to a coma, thankfully rare due to leaky old buildings and our inbuilt sense of stuffy air open the door/window. Likewise slipping into a coma after reading posts from PPP [:)]

[quote user="pachapapa"]

It is amazing how many chimneys in old houses such as mine which have had one metre logs roaring in them for three centuries creating such an updraft that the front door has to be opened to supply air; then a stove and installer arrive and surprise, surprise it needs excruciatingly expensive double walled stainless steel tubing.[:D]

[/quote]

Despite this bloke allegedly having a degree in engineering related matters it seems amazing that they haven't grasped the basic understanding of why a roaring open fire is different to a stove so the chimney/flue designs are different even though your links describe it very well. (open fire 95% of the heat rises up the chimney taking the gasses with it)

[/quote]

Allegedly[:)]

Imperial College of Science and Technology, Associate of the Royal School of Mines, date 8 july 1970..Signed Penney Rector, signed P.E.Mee Registrar

University of London, Bachelor of Science (Engineering) in Mining, date 1 august 1970, Signed by Academic Registrar ( but I cant read it)[:D]

[pachapapa]

Good morning Gengulpnus, I wondered if I could make a start to the evaluation of your chimney with the first crucial test.

1) Smoke Test

Please light a fire in your fireplace. Then go outside and look carefully at the chimney pot.

Can you see smoke?

Please report back your findings.[:P]

[Gyn_Paul]

[quote user="Théière"][quote user="Bill"]

An existing chimney must firstly be given a visual inspection,and make sure it is of a suitable size,a smoke test should be carried out to make sure it is clear of obstruction and check for gas tightness,your chimney should be swept before installing a new appliance,do not attempt to fit a liner without firstly sweeping the chimney,if your chimney passes the the visual inspection and passes the smoke test,it is deemed sound and not a legal requirement to line,lining your chimney has advantages such as increased draw and better efficiency,reduces the risk of chimney fire,and piece of mind having a sealed system

[/quote]

That is pretty much the nuts of the subject Bill.  I was corrected by someone who has been installing in France for years that twin wall (uninsulated) is not yet a requirement even for wood burners so single skin would do. In the UK HETAS only recommend single skin for gas burning flues, wood burning should be twin walled but by now you have probably noticed that in your links etc. Most of the wood burners if not all have the single skin and have been going 15-16 years.  I think the points I made are echoed in the links you have supplied so the final choice is yours.

The UK again recommends wood burners of more than 10kw must have an air supply into the room as the fire will draw in the air to combust and as air is 80% nitrogen 20% oxygen you can see that oxygen depletion is quite easy and so is slipping in to a coma, thankfully rare due to leaky old buildings and our inbuilt sense of stuffy air open the door/window. Likewise slipping into a coma after reading posts from PPP [:)]

[quote user="pachapapa"]

It is amazing how many chimneys in old houses such as mine which have had one metre logs roaring in them for three centuries creating such an updraft that the front door has to be opened to supply air; then a stove and installer arrive and surprise, surprise it needs excruciatingly expensive double walled stainless steel tubing.[:D]

[/quote]

Despite this bloke allegedly having a degree in engineering related matters it seems amazing that they haven't grasped the basic understanding of why a roaring open fire is different to a stove so the chimney/flue designs are different even though your links describe it very well. (open fire 95% of the heat rises up the chimney taking the gasses with it)

[/quote]

...That would certainly be the case if the fire was capable of selectively extracting the oxygen and then recirculating the nitrogen (along with the CO2 and NO for good measure). The more prosaic reality is that the fire would simply draw badly and ultimately go out completely. After all, the control devices on a poele are nothing more sophisticated than means of restricting the air-flow.

And as for sealing the top of the chimney to prevent the flue gasses from sinking back down the chimney cavity..... well all I can say is that it would have to have been a chimney with a pis-poor draw for this to be an issue.

My register plate sits on a metal rail on all 4 sides of the chimney but in no way is this an air-tight seal as can be demonstrated by running a lit taper around the joint: there's a slight up-draft: strong enough to pull the smoke through the joint, but not strong enough to blow out the flame (which is the case if I put same lit taper by the flue inside the poele). This effect is slightly greater when the poele is lit, which will be because the flexi liner radiates heat in a temperature gradient up the chimney, and consequently heats the body of air surrounding it in the chimney cavity. Given that there is a draft at the bottom, this heated air must be being drawn off at the top. However if the register plate (and flue entry hole) was an air-tight seal, then I imagine there might be some local convection currents circulating within the chimney space. but since it's airtight, the composition of the gas is irrelevant  !

Somebody earlier in the thread mentioned flash-over.  I'd be interested to read any technical data to support this seemingly wild notion.

And whilst it's certainly the case that the corrosive effect of a poele's flue gasses will do for lime mortar in the end, this is not like a gas fire's fumes which would silently kill; if fumes from a poele were leaking through the brickwork into - say - a bedroom, you'd be coughing and choking on the smoke and beating a path to the fresh air  l-o-n-g  before the CO levels became an issue. Just think how pleasant it is in a room with a fire that smokes.

;p