Anna Kettle wrote:
On Sun, 23 Dec 2007 13:54:14 +0000, The Natural Philosopher
wrote:

Thats interesting, so it is not essential for building regs to line a
chimney before a stove is put in. I have friends who have a big old
chimney very similar to mine, they didnt line their chimney and it
works perfectly well with a woodburner

It certainly is if its a new flue, I was made to line mine.

Where does it say there that you do not need one?

Nowhere. But equally it doesnt say that you do need one

It also does not mention flue heights above thatch either. Thats a
fairly crucial part of 'safe practice' for thatch.

It mentions height above combustible surfaces like thatch in the 'flue
outlet heights' section

However being as two of our neighbours are voluntary firemen, the number
of fires started from solid fuel in bad stacks is an extremely large
part of their duties..

There are regular pictures of such cases in the Bury Free Press, but
every single one I have seen has been in a house with a thatched roof
which makes me extremely suspicious that the problem is not with the
flue but with sparks shooting out the top, in which case a chimney
with a liner could be worse than one without

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.




So I'd like to know just what do your firemen mean by _bad stacks_?


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.


and having had sister in laws house burn down due
to unsafe operation of an unattended wood fire..

But was that anything to do with the flue????


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.




I am inclined to think
that a proper liner if there is ANY doubt, is something I would do
automatically.

Go on ... convince me! I'm interested in this cos I shall be putting a
woodburner in myself next summer and I dont want to do any unnecessary
work but on the other hand I dont want to be left with a dangerous
system either


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.


I've set chimneys alight on more than one occasion too. Is your
brickwork capable of sustaining a red heat..

It sustained a red heat when the bricks were made so I suppose so

how much timber is in
contact with it ?

Some ...

No. double skinned insulated stainless steel flues. I am not interested
in what you *might* get away with legally.

hmmm. You might be right ... but then you might have just fallen for
the hype :-)


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.