Ceramic chimney lining

[george [dicegeorge]]

A nice man visited from

quoted me £1908 to line a chimney with their ceramic slurry.

Any experiences of this kind of treatment?

[g]

[Tim Watts]

What's the chimney to be used for?

I had a SS liner put in for 1/3 of that (perhaps near 1/2 for your house if it is a 2 storey).

[george [dicegeorge]]

Estimated length of flue = 9.7m flue size 13 1/2" x 13 1/2"

There was a chimney fire in this fireplace decades ago. I want to be able to have an open log fire at Christmas!

But they say it will also do for a wood burner.

[g]

[Tim Watts]

My flue is about 7m - the price was for a 5" solid fuel SS liner.

[Tim Lamb]

Hmm.. Wood burners come with rather different flue requirements to an open fire.

Our particular one specified a 7" flue but most of the sub 12kW ones are

6". I think a 6" flue might be a bit small for an open fire.

IANAHetas engineer:-)

regards

[Onetap]

SS flexible flue liners are not regarded as permanent. They are not as robust as a cement/ceramic lining.

See the HETAS guide available on-line. All approved lining systems are listed.

This isn't the inflatable sausage technique; this one uses a cone that is winched up the flue. Slurry is pumped down and the cone renders the flue with the slurry on its way up.

[John MacLeod]

Yes -- similar treatment about 20 years ago to a chimney used with an open fire. No complaints at all. Very pleased with the work.

[www.GymRatZ.co.uk]

Nope, but just to add to the thread and perhaps get more insight..... A sealed stainless steel flue with a Gas appliance I can understand, toxic, nasty odourless gas and no sweeping required, but with an open fire or a wood burner which generally has to be swept several times a year (so I believe) if the chimney is sound then why a flue at all?

I banged my head about flues for both chimneys in our old cottage then came across a wood-burner site that mentioned it was a misconception, conjured up by the trade to squeeze more £££'s from your pocket.

Ended up not fitting a flue and making my own register plate with a short length of pipe from the wood burner through the plate to chimney and a separate sweeping hatch.

Been working brilliantly. Open fire at the other end also straight up the chimney works wonderfully too.

[Onetap]

Your post gives the impression that you believe a gas appliance gives off 'toxic, nasty, odourless' CO and wood burners don't, or are 'cleaner'. It is nearly the exact opposite.

All combustion processes give off CO2 and CO in various proportions. Wood (and solid fuel) burners generally work by having a fire bed of glowing coals/charcoal onto which fresh fuel is dumped. The heat pyrolizes the fuel, driving off combustible tars, volatile compounds and CO. Huge, ginormous concentrations of CO. In a gasifier, the combustible gases and vapours are burnt and the final combustion products are relatively 'clean'. In conventional open fires, the convection takes them straight up the flue, unburnt, away from the fire bed.

Town gas used to be made in the same way, heating coal to drive off the methane and CO. Sticking one's head in the gas oven was a common method of suicide because the town gas contained a lot of CO and was very toxic. It doesn't work now, natural gas is mostly methane.

Under these circumstances, a gas-tight flue, or as near as possible, is a sensible requirement.

Splendid, good for you, best of luck, may your chimneys never suffer a blockage. BTW, you're an idiot.

[Tim Lamb]

In message , Onetap writes

:-)

Also... A believable statement from the various log burner sites is that the flue gas temperature entering the chimney is high and carries the volatiles mentioned above in a gaseous form. Contact with a large, relatively cold flue may cause condensation leading to bleeding of distillates through the chimney brickwork.

The ceramic liner under discussion will have a relatively low thermal mass as do insulated stainless steel liners. Further, a steel liner is arranged such that any condensed liquid will trickle back down to the fire.

My mother burned a great deal of Elm in the days when the trees were dying. She used just such an arrangement as you advocate. Apart from a bit of staining on the plaster surround she got away with it. However, after her death and during some building work, the builders managed to set fire to the chimney.

regards

[www.GymRatZ.co.uk]

I must be missing something. If your SS flue tube gets a blockage how is it safer than a "sound" chimney getting blocked? Dare I say a "full bore" chimney is actually far less likely to get blocked than a 6" dia. 10m length of corrugated steel?

If there is blockage in either will the effects not be the same? A wood burner is "sealed" through the register plate. any blockage will manifest in a fire that either won't light or won't burn (starts smoking in the fire box) due to lack of draw. Non combustion and certainly not a house engulfed in deadly fumes.

What about the following page:

clue is in a "sound" chimney. If your chimney leaks then a wise man would fix it rather than masking the real problem with the "temporary" solution of a liner.

[Onetap]

The assumption seems to be that a 'sound' chimney is equally impervious and liable to blockage as the same flue with a liner.

The products of combustion contain both water vapour and acidic compounds and attack mortar (especially lime mortar) and masonry. Brick and masonry flues get blocked by falling masonry and soot. I've also seen a flue, in a terraced house, in which a brick had been dislodged into the flue by trying to nail on a skirting board in the adjacent property; there was smoke stains originating from behind the skirting. If the flue is sound, swept, preferably inspected and smoke tested, I might then be inclined to trust it without a lining. IMHO it is unusual to find a masonry chimney that is 'sound' without some repair or lining; I don't sell liners.

Ceramic refractory cements have been used for centuries to make furnaces and line boilers.

An acquaintance had a chimney fire (abroad) and was advised to let it burn itself out; tipping water down the flue would have cracked the stonework and allowed flames into the building.

[www.GymRatZ.co.uk]

Thankyou :¬)

[The Natural Philosopher]

The current building regulations mandate that open fires flues be lined with something - in my case ceramic flue sections with a special cement

- and that all stove etc. flues be lined with an appropriate (steel ?) liner. Again your reasons above are clear and AFAIK correct,.

Its not illegal to run an existing mere masonry chimney that's been going for years, but it is not advisable either. One of the chief causes of house fires in properties so equipped is in fact a chimney fire that leaks hot gases through failed flue mortar joints, and sets fire to adjacent wooden structures - or thatch (round here) - usually roof timbers or joists mounted off it.

Blocked flues and suffocated occupants are seldom an issue with open fires.

The house will be full of smoke long before you are in danger.

[george [dicegeorge]]

Whilst it may not be illegal to run a burner up an unlined chimney it may invalidate insurance.

I think its illegal to install a new burner without a liner in an old chimney.

[g]

[www.GymRatZ.co.uk]

This was my main point. A house full of wood smoke isn't the same as a house full of smoke from burning carpets, curtains, sofas, plastic etc etc that would come from a full-blown room fire.

The other bit about early condensation of flamable substances (creasote etc) on the wall of a "wide" chimney (not flued) due cooler gases etc etc causing an increased risk of chimney fires don't really make sense in the "real" world..

If we have typical modern wood burner running somewhere between 70 to

80% efficiency, that already knocks any flamable substance matter getting out of the burner and into chimney cavity to a small amount (compared to an open fire) as much is burned as a secondary combustion in the fire box/combustion chamber. Following on from that, the very design of a wood burner is to have the flames (and heat) that escape the combustion chamber wondering through a series of plates and baffles etc to extract as much heat to the burner as possible so I would also say it is impossible for any flame to extend beyond the confines of the burner, let alone then go up the connector pipe and meet with residue on the wall of the chimney.

Just my ponderings. :¬)

[george [dicegeorge]]

Sometimes the tar in my chimney would ignite and I'd go outside and watch a beautiful one foot flame coming out of the top of my chimney when I was burning all sorts of rubbish in my rayburn in my bus.

[g]

[Onetap]

You get something similar nowadays with fast food joints and kitchen extract systems. Grease condenses in the ducts, accumulates, ignites, blaze fanned by extract fan, etc... ISTR there were such fires at South Mimms services, Gatwick & Hamburg (?) airports. Predictable and avoidable.

I don't claim any particular expertise on CO poisoning, but I think the last statement is very dubious.

There was an incident, described to me in graphic detail, involving a couple who entered a house in which a stove flue was leaking, but apparently without noticing anything amiss. Both died, within minutes

[george [dicegeorge]]

Not pumped, They said they'd run up stairs and ladders with buckets of slurry and pour it down the chimney as they winch the plug up.

There's a Before and After picture at:

[The Natural Philosopher]

Umm. yes and no.

WEhen I queried my 'thatch premium' the insurance company said that unless I had done X, Y Z etc then it would stay.

I had done X, Y, and Z as part of the new build. A visit from a loss adjuster and a requirement to fit a loft smoke alarm plus have fire extinguishers, sorted it all out.

Mind yo the premium reduction was not very much.

AFAIK that is correct..if by illegae you mean 'contravenes building regulations'