log burner

[andrew heggie]

Maybe but consider also that wood will start to smoulder at

[The Natural Philosopher]

Nope. It seems that what is most common is a leaky stack inside the thatch where you don't see it.

People point up where its visible, and can inspect teh loft, or smell smoke.if the leak is inside..but if its inside the layer of thatch there is no sign of the leak until the thing goes up.

Mostly you don't have fires in dry weather..sparks tend to go out on the wet thatch. Not saying it doesn't happen,but the usual starting point is underneath the wet stuff wheer its nice and dry.

What I have described. Where there is a leak in the stack and hot gasses can escape sideways. Now that may not be a problem until and unless the stack catches fire internally. At that point you have all the ingredients for a disaster.

No, that wasn't specifically. Although it was a contributory factor. The main point was that any chance I have to reduce fire risk is worth thousands to me. A grand on a flue liner in an unknown chimney is cheap at twice the price.

I take it as read that a chimney WILL catch one day. I want hermetic seals all the way up. Insulated flues are good in that they get very hot very quickly and prevent soot condensing.

Just ask yourself if you can guarantee that there is no place that you can't see, with loose mortar, and assume that one day the thing will catch fire..even if its only the pigeon that fell down it in the summer.

Now, do you feel lucky today? Every chimney fire I have had, has been out inside if 5 minutes. *I* know what to do. I am less sure that my wife does.

Or someone who might be tending the fire while we are out taking the dogs for a walk..if indeed we didn't just leave the fire unattended.

Hey: It's your life and your house.

No. I personally would have been happy with a flexible liner, but the BCO said no, if it isn't clay block lined, its essentially doing nothing. AND made us put fireproof board round it where the timbers hung off it.

I am not renowned for being a fan of Elfin Safety, or silly regulations, but where fire is concerned I have seen the devastation it causes, and I am bang on or beyond all fire safety recommendations. Its the same with cars. I've been motor racing too often to even THINK about driving without a belt and strap on. I was even responsible for fire issues at two of the companies I was director of..if you don't want the BCO involved, go and talk to the local fire safety officer: I did. They will be most helpful and are probably the least biased people where this is concerned. They will spot the weak points.

You SHOULD IIRC go 2 meters above the thatch for spark safety. Which is a pain in an existing listed property. I was lucky. I just stuck pots on the stacks so it didn't look too ugly.

I've even got fireproof board on top of the roof, under the paper and before the thatch..if the thatch goes, as long as the boys are there in time, it shouldn't take the house with it..

If you ever do a complete strip and rethatch job, its not a huge extra cost to do that. Every little helps.

Fire has not been a political hot potato: The Fire building regulations have been developed by fire officers and engineers, not by politicians and bureaucrats. To my mind they are sensible and well founded. Every last inch of them. Flues, hearths, distances from stoves to combustible materials, ventilation.

The principal is to work on the assumption that one day there will be an uncontrolled or out of control fire. The essence of fire safety is first of all to protect human life by slowing down the rate of progress, raising the alarm, and making alternative ways out available, and secondly to limit the scope of the fire to limit property damage.

Only then do you put the icing on the cake by dealing with issues that may actually START an uncontrolled fire.

But you shouldn't rely on them.

Having a quality steel liner may help to reduce the chances of a stack fire, but the real issue is that a stack fire just makes a lot of noise and sparks, until you can damp down the fire and starve it of oxygen. Then its just an exciting episode. If the stack leaks, you can't put it out, and air can be drawn in to feed it and hot gasses can escape to start secondary fires.

[The Natural Philosopher]

Odd that. as the aga which is essentially that, was specified for an insulated flue. Albeit of a lower spec than the wood burner.

[The Natural Philosopher]

Slightly.

The trick is to put the fire out quickly with water, and then block the chimney.

Ive used a bucket of water for the first, and a couple of newspapers over an open fire face for the second. This is the 'approved' method. With a stove although its slightly harder to put the fire out, its a damn sight easier to starve the airflow. Shut all dampers and doors.

Regularly used flues with wood need sweeping annualy. maybe more with unlined ones.

The one that I set alight three times in a row, was an open wood and coal burner that had been swept about 18 months previously, but was the second source of heat in the house apart from a coal aga.

The other one was similar, but hadn't been swept for several years

[The Natural Philosopher]

Do you feel lucky today ;-)

I think Anna's place is thatched..the sparks CAN be a bit of an issue..if you have ever seen a stack fire you will know it looks like a giant firework going off. HUGE draught and white hot flakes of soot being blasted into the sky. If its a cold still dry day..they can and do fall back down. No problem on slate or tile, but less than ideal on damp thatch.

[mail]

Dear Anna and Staffbull

1) "The 2002 edition of Approved Document J of The Building Regulations stipulates that any work that affects an existing chimney (ie fitting a new stove or liner) or creating a new chimney now comes under building control" 2) "An existing chimney or a new flue or chimney installation must be given a visual inspection to check that it is in good order, clear of obstructions and is of a suitable size and type for the appliance you plan to install. It may be necessary to sweep the flue (which should always be done anyway before fitting a stove or lining a chimney) and also, if necessary, to do a smoke test to check for gas tightness. "

As the wood burner is more efficient than on open fire I understand from the literature (but may be wrong) that there is a much increased risk of condensate of wood extractive then lining the flue and becoming a fire risk in itself which is why double lined insulated flues were invented and put in.

Generally speaking, I researched this and found that it would be at LEAST twice the price of the stove to get it installed properly and that I had to have a positive air supply which rather ruined my plans for air tightness so I now have a normal fireplace and flue and keep the flue closed when not in use

If you have access to lots of free wood and can store it on the premises then go for it but it will cost and even if you do it yourself you will need a helper to put in the liner and it will take twice the time you think it will! chris

[Anna Kettle]

No its not and I think that is actually a blessing in disguise cos though it may look pretty thatch is expensive to maintain and risky to light fires underneath. The house used to be thatched until 1960 but then it was given a new roof of concrete tiles. Must have been very ugly initally but now they are covered in lichen and look ok

Anna

~ ~ Anna Kettle, Suffolk, England |""""| ~ Lime plaster repair and conservation / ^^ \ // Freehand modelling in lime: overmantles, pargeting etc |____|

[oldship]

There can be a lot of heat energy stored if you have good fire going though whether its open or in a stove. It may be the approved method but pouring a bucket of water onto a healthy hot pile of wood and ash can produce an amount of steam whose affect in an enclosed room varies from mildly alarming to enough to cause scalding. ISTR that if that bucket held one gallon of water and it all turned to steam it would take the space of about 1600 buckets.

For anyone who has to do it watch the hands and face.

G.Harman

[Anna Kettle]

Yes I suppose that makes sense. If there is a tiled roof then the hidden bit is much smaller, just where the flashing goes

That sounds like a good idea. I'll do that

OK you might have convinced me :-)

Anna ~ ~ Anna Kettle, Suffolk, England |""""| ~ Lime plaster repair and conservation / ^^ \ // Freehand modelling in lime: overmantles, pargeting etc |____|

[Anna Kettle]

Can you elaborate? If the stove is small then regs say a vent is not needed. Is that what you are talking about? My stove will largely be for decoration and for enjoying the log fire and maybe boiling the odd kettle so I thought I would just get a small stove, though I dont think that putting in a vent will be difficult to do. Why did you want it to be air tight?

BTW I have been told that the best places for a vent are high up in the same room or low down and very close to the stove. Low down and away from the stove produces draughts round the ankles

Yes I can do that

Everything does! Especially things I have never done before and this is a prime example. However I will have the advantage of a proper scaffold in place cos I'm planning to repoint the stack and remove the chimney pots at the same time

PS Anyone in the market for a couple of large Victorian chimney pots?

Anna

~ ~ Anna Kettle, Suffolk, England |""""| ~ Lime plaster repair and conservation / ^^ \ // Freehand modelling in lime: overmantles, pargeting etc |____|

[andrew heggie]

If I didn't have bad luck I'd have no luck at all :-)

I was taking the point about sparks as being read. Yes I have had a chimney fire and it was spectacular, 1974 IIRC. That was an open fire and needed a fireman with a set of rods with a hose attached and a stirrup pump in a bucket of water to extinguish, very messy. I wouldn't expect any where near the same problem with a properly installed stove. The trouble is that a normal sweeping will not dislodge much of the tar deposits.

AJH

[andrew heggie]

The aga is massive but its flue is just a means of exhausting the gases, there's no scope for getting more heat out of the flue gases so they should not be cooled further, and as they are already quite cool they can use a cheaper liner if fired on smokeless fuel, gas or oil. The aga I mentioned earlier that would not draw simply did not have enough heat in the flue gases to warm the massive chimney it was exhausting into, as well as the other problems I mentioned.

The masonry fire is actually built into the chimney breast that then becomes a "radiator" and thermal store, so the flue reaches high combustion temperatures but is cooled by the massive structure. I'm not familiar with them but I would expect the flue gases to actually leave the top at a similar temperature to a conventional wood stove >150C.

AJH

[The Natural Philosopher]

No. You can put your hand on the stove pipe. It's nearer 60-70C. For an aga.

VERY efficient heater. More so than a condensing boiler IMO.

[The Natural Philosopher]

You obviously have NOT done it.

The steam gets drawn up the roaring chimney.

[The Natural Philosopher]

It dislodges the crud that burns. That much I know.

[Huge]

Not a flame(!), but it's "hypocaust".

[The Natural Philosopher]

?

In my case it was about a grand to do two pipes..one downstairs from the aga, one upstairs from a wood burner.

The air feed was accomplished by a 4" p[ipe into the loft for the latter, and a underfloor vent of tow 4" pipes for the aga.

[The Natural Philosopher]

Ideal. if the flues are straight you simply drop it from the top in sections, and hold it there with a plate on the stack top.

The problems happen when you have cranked over stacks.

5 years too late. ;-)

[andrew heggie]

No it's christmas ;-) and I think you are right but:

Hypocaust would be the bit under the floor, I think the flue passages also ran up the walls and I have seen a square flue wall tile described as a hypercaust but that equally may have been wrong. I was describing a vertical chimney breast that was designed to absorb heat and then slowly release it to the room.

I know the derivation of hyper and hypo but whence "caust"? Caustic is used to describe alkaline substances that burn. I'll have to remeber to look one day.

AJH

[andrew heggie]

I was comparing the chimney outlet of a masonry stove with that of a conventional stove, not agas which I had earlier said had low temperature flue gases,

:-) I've left my personal opinions of agas out of this....

AJH