Inglenook fireplace

[Helstonboy]

I have just found a beautiful granite inglenook behind layers of 60s and 70s and earlier horrid building additions in my front room.I removed 6.5 tonnes of rubble and what look like and original slate roof(obviously smashed to bits which is also a shame)......anyway I digress
I have now pointed up all stonework with lime mortar and laid a huge granite hearth stone,put in a big grate and dogs etc and hood the hood is not sealed in and only collects smoke from fire to funnel up chimney which is huge all the way up.....it is approx 36inches wide and depth 18inches (that is all the way from above the gather to almost top slightly tapering....it is a thing of beauty and me thinks possibly Tudor in timescale). The fireplace opening is 50inches wide and 46inches to the granite beam.
I lit our first fire and guess what.......room soon backfilled with smoke though the chimney was chuffing away! Then the loft filled with smoke and smoke came out the eaves!!
We really want to keep an open fire in this place as it looks great and feels great. It is not the main fireplace and will only be used occasionally. I think trying to repoint whole inner chimney will be too costly?
Therefore I thought of lining the chimney with insulated flue? To join onto the hood and then weld a register plate to the hood as well to seal the chimney. Would this work? Has anyone done this before?
All help really appreciated.
Thx
Iain

 

[88v8]

Hello and welcome.

Well done with the restoration.
Shame about the smoke.

Two reasons; first, to get air out of the house - up the chimney - there needs to be air coming in. A lot of air.
So if the house is now sealed up with all 'draughts' eliminated, that's the first problem. There needs to be good ventilation, ie draughts, around the windows and doors as would have been originally. Or if you don't fancy that, vents into the room, preferably into the back of the hearth. This may be accomplished with a diamond core drill, depending on access and wall thickness.

The second problem is one of ratio and velocity.
The ratio of fire opening to chimney cross-section is about 3.5:1, which is excellent, most fire openings are too large but not in your case.
But, the chimney cross-section is so great that until the fire is thoroughly warm - and bear in mind in winter it would probably never have been allowed to cool - it will not pull. The air will just loll about and not rise up the stack. Are you into cars? Think inlet velocity, overcarbed, no torque. Same thing.

So, yes, flue liner, I'm sorry to say. This will increase the stack velocity and stop the smoking. Six inch will do it. As you say, insulated, with a jacket, then if you wish in future you could run a wood burner.
The liner will also cure the smoking into the attic, which arises from defective parging in the flue. Over the years the parging has fallen off, the pointing has decayed and fallen out. This would not be such a problem if you had good stack velocity, but the possibility of smoke percolation will always be there.

Hood may help. No need to weld it. If the stack is pulling well, the smoke will go up regardless.

As the flue is so wide, it would be nice to preserve the visuals, so if you're willing to experiment, I might start by leaving the bottom 4 foot bare, in other words fit the register plate and hood up inside the flue, then of course the liner. Bit more fiddly, but with a X-section of 36x 18 there is room to work. Then you can repoint the bottom 4 foot of the flue. And if you wish you could put a small uplighter in there to show off the flue and your handiwork.

There is a risk in starting 4 foot up. The chimney needs a good pull, or you may find when the flue is cold, the smoke mills around and doesn't rise.
How tall is the stack?
Is the house listed?
Could you put a pot on there to increase the velocity? In any event, with a flue liner you have to think about the flue terminal, its appearance. Don't want to uglify your stack.
We have a C17 stack with a C19 pot and a UFO 2.

Some thoughts.

Ivor

 

[Flyfisher]

Some more info here: http://solidfuel.co.uk/pdfs/curing_chimney_problems.pdf

 

[Helstonboy]

Thanks Ivor for the reply and fly fisher for the link.

The stack is approx 12m and I have fitted a stunning hand thrown c18 pot with thumb print on top which pulls like a good un!
Luckily our house is not listed!! Even though it appears to be older than anything around us for some distance and is architecturally a one off. Still I never understand the reasoning behind what is and isn't (another quandary)

I am thinking of getting that 6 inch line and jacket and cracking on. I agree that he way forward should be to leave 3 or 4 foot of chimney so as not to ruin the aesthetics.

Iain

 

[88v8]

Good link.
Which reminds me, I might have commented that once you put in a flue liner, the inglenook fire opening will then be too large in relation to the flue, and you will need to counteract that by sitting a hood fairly low over the grate. But you could still run a bare 6" stove pipe from the hood for the first few feet to show off the flue brickwork.

Ivor

 

[Kearn]

for various reasons, we are keeping a woodburner in our inglenook which has been (relatively) recently opened up and restored to original footprint. however, the opening and brickwork is too nice to obscure, including the slowly corbeling full width flue - I wish we didn't need a register plate at all, but my compromise is having it fitted 5ft above the woodbunrer so you can still walk into the opening and stand up. that way at least one of the original huge nails is visible, which used to serve as a rudimentary step for the kids to climb up to sweep many centuries ago...

we ummed and aared for ages on having an open fire, but personally I prefer the look of a woodburner than a hood if one has to be inserted to the opening and our double doors open fully so we can almost have the same sound and smell of an open fire but maintain a draw, especially as we have a pesky yew tree in very close proximity to our stack exit.

presume you might, (or likely might not if your rate of progress is akin to many of us on here :roll: ) have finished by now - any pics??

 

[Flyfisher]

We also went with a woodburner in our opened up inglenook, in our case a boiler stove that also heats the DHW and supplements/replaces the gas boiler.

I think a register plate is effectively an inevitable requirement but I agree about fixing it high enough up the stack so not to be readily visible in the room, even when sitting down. I fitted a simple angle-iron frame into the stack and fixed the outside pieces into the stack using screws before tack-welding each corner. I then added two cross pieces and tack-welded these in place. This gave two largeish openings each side of a smaller central opening for the the flue pipe. I then bought some cut-to-size galvanised steel sheeting and simply laid these into the angle-iron frame sections, first cutting a hole for the flue pipe in the central plate. I had intended to drill some holes and use self-tapping screws to secure the steel plates but in the end didn't get around to it and haven't since found it necessary. This makes it even easier to lift one or both of the side panels as necessary.

The following photos hopefully make things a bit clearer:

 

[Flyfisher]