tar box

[charlie-ia]

whats the word for that little hatch / box in the chimney for collecting tar from a range /stove?

are they avoidable? my parents have one that they were advised to put in, they hate having to clean it all the time and it weeps nasty brown stains down the wall (phaps its just badly built)

found a good simple website, chimneys.com (though it does mention rather a lot about raccoons)

 

[Penners]

Our woodburning stove was installed a couple of years ago by a specialist company, who are well-known experts in this area. They made no mention of such a thing.

The main principle these days seems to be to try and ensure that the flue gases from a woodburner stay hot enough all the way up the chimney to avoid the tars condensing out. So the stainless steel flue was passed up the chimney and then the void around it was filled with vermiculite granules as insulation.

 

[Lime]

Wood when burnt in an oxygen-starved atmosphere (as in an enclosed stove) produces a lot of tar.
Most chimneys built for coal burning do not handle the condensed tar well. It can cause very bad staining coming right through the brickwork of the chimney and mark the walls.
It is a fire risk too.
Penners lined chimney is the best way of avoiding trouble.

 

[Flyfisher]

I understand the need to keep the flue gases hot to avoid condensation but is it generally better to use an insulated liner (double-skinned I think) or a single-skinned one and then fill the chimney with vermiculite, or similar?

Or does it depend on the existing chimney, in which case how would you decide the most appropriate option?

 

[MdB]

Penners lined chimney is the best way of avoiding trouble.

Do you have to roll him out thin to get him to fit?

 

[NT]

Perhaps Lime meant Penne, which comes in ready chopped tubular sections?


NT

 

[charlie-ia]

I guess turf burns comparitively cool to coal. know how it compares to wood?
Ill ask them if their chimney is lined (bet it isnt)

 

[middi]

I have fitted a few wood burning stoves and have always used a double skinned S/steel flexible liner of diameter relevant to the stove's requirement. They work perfectly without insulation backfill.

I am sure that backfill aids thermal efficiency, especially if the chimney is exposed and not internal, nevertheless, I think it is more important that the wood used is very dry and of good calorific value.

The beauty of this simple arrangement is that a woodburning stove can usually be installed in a couple of hours.

 

[Lime]

MdB & NT :lol:


'


please place in my post where thought appropriate.

 

[andrew gayton]

do you mean the soot door to a chimney to enable sweeping above a register plate? (if unlined with aftermarket flue)

 

[charlie-ia]

thats the thing! thankyou kindly (hard to search when you dont know the name - have you seen how many posts there are for "chimney" ?!)

 

[Nemesis]

Is this on an interior or exterior wall?

We have one for our solid fuel stove which is simply there to collect fly ash really, and allow the chimney to be swept. On our woodburner we have a plate in the metal flue pipe leading from the stove which can be removed to allow sweeping, but it doesn't weep tar.

If wood is well seasoned I would have the thought tar shouldn't be collecting in this way very readily?

 

[charlie-ia]

interior wall, range burning hand cut turf. the walls white so any stained moisture really shows up

 

[Nemesis]

Well if possible I'd move it pronto, if possible to the outside wall, or get a new flue like ours with a plate on it.

Seems a very strange place to have it. I have never burnt turf but I'm surprised that it's making so much tar.

 

[charlie-ia]

youve got me worried now, i thought it was just very inconvenient.

is it dangerous?

the chimneys about in the centre of the house, on an internal wall. parents dont have a phone or i'd ring and ask more details

 

[Nemesis]

No I doubt it's dangerous, although a tarry build up can cause chimney fires. But I agree - having it on a wall and making a mess isn't a great idea.


I think I'd be investigating a new metal flue pipe with an access for cleaning which then shouldn't drip tar down the wall! But our woodburner is in use with a lined flue.

 

[andrew gayton]

Mine is on an inside wall, just had a look-see inside over lunch and it is dry, just ashy..... sounds like a lot of condensation....... saying that, i know nothing of turf burning dynamics.

 

[Nemesis]

A bit of history...

http://historical-debates.oireachtas.ie/S/0031/S.0031.194604110004.html

 

[Penners]

is it generally better to use an insulated liner (double-skinned I think) or a single-skinned one and then fill the chimney with vermiculite?

Ours actually has both. I think it's known as "belt and braces"!

 

[Penners]

Penners lined chimney is the best way of avoiding trouble.

Do you have to roll him out thin to get him to fit?

The words "Penners" and "thin" have never before been used together.