An extra little flue!

[charlieboy]

The chimney shown in these photos has two normal flues each with a chimney pot as you would expect. There is also an extra flue about 4 inches square which terminates not with a pot but with the two vents as shown in the photos. These two vents are opposite each other and from a distance you can see straight through both of them. This small flue starts just above the ground floor fireplace.
I don't think I have ever seen anything like it before. What do you think it could be for?

The first photo was taken from a new roof light and the inside of the 10 foot high parapet can be seen.

 

[a twig]

Initial thoughts would just be that it is a small flue that is no longer used, so has been capped and had air vents installed in the top to prevent damp build up.

Can't think of anything else, is it connected to anything? You say it comes out above the main fireplace, comes out into what? Or does it come off the main flue?

 

[Flyfisher]

Could it be that the chimney has been lined and the small grilles are to ventilate the chimney void?

 

[CliffordPope]

Is the fireplace an ordinary one as in a living room, or from a kitchen ?
Could it be the additional smaller flue for a bread oven? Our house (c1880) and cottage (18th century) have these from fires that in each case were originally in kitchens.
The one in the house has been blocked up and a window inserted next to the main flue, but in the cottage the whole built-in oven and door is still intact. The house exited at an additional ordinary chimney pot (now capped), the cottage flue goes up inside the wall about 6 feet and then emerges into the upper regions of the big chimney.

In each case, a smaller fire would have been lit to one side of the main range. It's hard to see how it could get hot enough to bake bread, but maybe as a constant ideal temperature for rising?

 

[charlieboy]

Thanks for your thoughts.

I have not dared to go up on the scaffolding to look but my builders tell me that the 4 inch flue seems to be that size all the way down, and has no soot in it. So the idea of a bread oven or a previous chimney blocked off does not seem quite right.

The flue comes out in the ground floor room which has previously been a kitchen just above where the range would have been.
All I could think was that perhaps it was to remove steam from boiling pots and pans - a sort of 1800s extractor fan. This does not seem right though as a lot more air and steam would be drawn up the 9 inch chimney with a fire under it than a much smaller flue nearby with no fire. Unless of course if the fire had a damper which closed it completely then this small flue would take away any smoke which came into the room.

I wonder if you could sent a ferret up the flue to catch pigeons that landed on the chimney.

 

[jjj75]

FIrst post here, but I had an idea on this one, so thought why not...

Could it perhaps be to allow fresh air into the room?
The open fire/kitchen range will want to pull air in from wherever it can, and if the room isnt sufficiently drafty, has solid floors and few windows, then it will not burn well and may try to pull air down other chimneys bringing with it some of the smoke/fumes from the lit fire under the adjacent chmny pot.
This wiould reduce that problem.

Just a thought.
JJ

 

[CliffordPope]

But a fresh air duct for a fire would need to be at floor level, not above the fire.
And a flue from a warm room emerging at a higher level would have an updraught, just like a chimney.

I still thinks it's for a bread oven. The absense of soot just means it's never been used, or else was used so long ago that traces have disappeared. Only the top has been inspected I think - that might have been cleaned by wind and rain blowing through the two grills.

 

[Keith Bowman]

Bread ovens - I was told (but have no idea how accurate this is) that bread ovens were heated by burning bundles of small dry sticks ('faggots') which produced a lot of heat with very little smoke. There were also reputed to be stones of some sort which changed colour when the oven was hot enough to bake bread.

 

[plasticpigeon]

Which room does it go to? Could it have been for a copper which heated water?

 

[LadyArowana]

The absense of soot just means it's never been used, .............

Probably one of my relatives!

 

[noj]

My bread oven has a vent above it into the main inglenook flue although there's no actual flue in the oven itself. The brick arch isn't mortared though - I assume smoke filtered through into what may be a cavity there and then back into the main flue?

In my case the bread oven looks like a later addition (albeit pretty ancient) - I guess if one was part of the original construction it could well have included a little flue of it's own...

 

[charlieboy]

Thanks once again for your ideas.
This is a photo I took this afternoon of the lower end of the narrow flue. It can be seen inside the fire surround at the top on the right hand side. I hope this makes it clearer.
The room has sandstone walls about 2 foot thick built about 1600 we think. The chimney breast including the narrow flue is a brick addition on the outside probably built about 1800.

 

[CliffordPope]

The oven in our house looks like this: (about half way down0

http://colonialquills.blogspot.co.uk/2011_12_01_archive.html

ie the bread oven is outside the main hearth.

The one in our cottage has the oven inside the hearth in the back wall, with a small flue in the top corner just like yours.