Stuck chimney flap

dr.fuzzenstein · 15-12-2014 7:01pm #1

I have a large fireplace into which I am going to install a woodburning stove.
I have all the bits and pieces I need, but I have a problem:
About halfway up the chimney a flap is fitted, with two pullchains, open and close.
The flap hasn't moved in years and is stuck solid.
First I swung off the chains, but 110 kg of me wouldn't budge it. Next I managed to lash a belt round it and pull it with a ratchet strap, 200 kg, it broke.
There followed me on my tiptoes hammering the flap with a large and heavy metal pole. Flap laughed at me.
After that I got a brace (the kind that holds roofs up on building sites) and I tried the screw mechanism to force the flap the other way, nothing.
My last attempt was to butt the brace against the chimney flap and putting a car jack underneath. In the end I could feel the bypass valve activating.
So, solid metal pole and 2 tons of pressure didn't even slightly shift it, it feels like the flap is solid concrete.
It is too small to climb up there and I can't send a child up there with a grinder or blowtorch.
So those are out.
How on earth could I possibly get that flap open, or rather, completely out of the way? I need it gone.
Any advise appreciated.

Cerco · 15-12-2014 8:16pm

Perhaps it opens upwards? Have you tried pushing a chimney rod up?
Apologies if this is a silly suggestion.

dr.fuzzenstein · 15-12-2014 8:35pm

Cerco wrote: »

Perhaps it opens upwards? Have you tried pushing a chimney rod up?
Apologies if this is a silly suggestion.

Any suggestions welcome.
It opens on a swivel point in the middle, i.e. towards the front is a lip on which it sits, meaning the back swivels down.
Right now it doesn't swivel any way, at least not with a mere two tons of pressure.
The aim is not just to open the flap, but to get it out completely.

Right now I have a watchermacallit that is used on building sites to support ceilings (I have no idea what that is called, any help appreciated), the plan is to use a very heavy duty jack that is used to jack up ceilings in order to hopefully break the flap and get it out of the way.
Any ideas welcome, even Wile E Coyote stuff like firing a giant rocket up the chimney.

Man of Aran · 15-12-2014 8:44pm

dr.fuzzenstein wrote: »

Any suggestions welcome.
It opens on a swivel point in the middle, i.e. towards the front is a lip on which it sits, meaning the back swivels down.
Right now it doesn't swivel any way, at least not with a mere two tons of pressure.
The aim is not just to open the flap, but to get it out completely.

Right now I have a watchermacallit that is used on building sites to support ceilings (I have no idea what that is called, any help appreciated), the plan is to use a very heavy duty jack that is used to jack up ceilings in order to hopefully break the flap and get it out of the way.
Any ideas welcome, even Wile E Coyote stuff like firing a giant rocket up the chimney.

The doo- hickey is called an 'ackrow jack' I reckon.:D

It may be necessary that you have cut a slot externally on one side with a concrete saw to remove the frame to which this flap is attached.
Get your measurement carefully from hearth to this obstacle and transfer this measurement to the wall you will cut the slot.

Afterwards you can "make good" on the slit and re plaster. Presume you will run 5 or 6" flexi flue and vermiculite etc concept inside this old chimney anyhow so fumes or leak stains would not be primary concern. That's my 10cents worth.

dr.fuzzenstein · 15-12-2014 8:58pm

Man of Aran wrote: »

The doo- hickey is called an 'ackrow jack' I reckon.

It may be necessary that you have cut a slot externally on one side with a concrete saw to remove the frame to which this flap is attached.
Get your measurement carefully from hearth to this obstacle and transfer this measurement to the wall you will cut the slot.

Afterwards you can "make good" on the slit and re plaster. Presume you will run 5 or 6" flexi flue and vermiculite etc concept inside this old chimney anyhow so fumes or leak stains would not be primary concern. That's my 10cents worth.

That's the thingymabob!
The problem with the chimney flap is that it is halfway up the chimney, so can't get at it from the outside, too much house in the way and the front of the chimney is clad in solid stone, so no way to get at it.
Right now will butt the ackrow up against the flap (maybe weld a spike on top of it to concentrate the pressure on a small spot) and put one of these underneath it:

2 tons didn't shift the flap, but I reckon 20 tons of pressure should hopefully break even the strongest steel flap. I'm going with the Jeremy Clarkson method, sheer power didn't solve it? Moar power!

Man of Aran · 15-12-2014 9:16pm

Best of luck with it, be careful you don't damage the chimney inners with all that force. Is it an old masonry chimney or terracotta liners and what shape is it . Pix may help but with poor lighting, I know that's difficult to take.

It's a mystery why it does not budge so far, is it possible that somebody threw a few buckets of mortar down from top over the years to seal it semi permanently?
Have you got scaffolding up and/ or slate ladder so you can take a look down from top, might schedule some light on what's holding it so stubbornly.

Alun · 15-12-2014 9:24pm

Man of Aran wrote: »

Best of luck with it, be careful you don't damage the chimney inners with all that force.

Yes, I'd be worried about that too.

dr.fuzzenstein · 15-12-2014 11:02pm

Man of Aran wrote: »

Best of luck with it, be careful you don't damage the chimney inners with all that force. Is it an old masonry chimney or terracotta liners and what shape is it . Pix may help but with poor lighting, I know that's difficult to take.

It's a mystery why it does not budge so far, is it possible that somebody threw a few buckets of mortar down from top over the years to seal it semi permanently?
Have you got scaffolding up and/ or slate ladder so you can take a look down from top, might schedule some light on what's holding it so stubbornly.

I will take a few pics later, phone out of juice right now.
Viewed from the living room the chimney is clad with solid stone from base to roof, very thick, under that is concrete and I'm not sure as to the inside of the chimney, can't see it, but most likely lined.
The house itself dates back to around 2000, so would expect a fully lined chimney to which the stovepipe can be directly connected without the need for additional liner.

slimjimmc · 16-12-2014 12:35am

It's a mad idea but if you can get to it with an ackrow then you may be able to get to it with a cutting torch or a reciprocating saw/angle grinder taped to a length of timber/metal tubing. If the powertool has a screw-in side handle you could use it to bolt on a bracket to mount it to the timber and add some sort of spacer to resist kick-back.

dr.fuzzenstein · 16-12-2014 1:28am

slimjimmc wrote: »

It's a mad idea but if you can get to it with an ackrow then you may be able to get to it with a cutting torch or a reciprocating saw/angle grinder taped to a length of timber/metal tubing. If the powertool has a screw-in side handle you could use it to bolt on a bracket to mount it to the timber and add some sort of spacer to resist kick-back.

Thanks, that is certainly a possibility.

dr.fuzzenstein · 20-12-2014 4:21pm

OK, update.
Put down solid, flat timber on the floor, 20 ton bottle jack on top and an acrow.
Jacked it up and the acrow bent like a straw.
Here some pics

Chimney from the outside

This is what you see when you look up.
This looks larger than it is. The flap is 3.4 meters up and measures about 70cm x 30cm and the hole is too small to get up there.
There is of course always the option of sending a child up there with an anglegrinder or cutting torch...

Man of Aran · 20-12-2014 9:27pm

Gee, it's a tight spot alright.
Any idea who inserted that or when/ why. Are you original owner.
BTW you missed one pix from outside. Is this a semi or detached and I don't see why cannot a slot be cut from outside if it's not on a party wall.
To me a slot is still best and safest way rather than trying to use cutting torch from underneath unless you know some smallish circus worker types.

dr.fuzzenstein · 20-12-2014 9:33pm

Man of Aran wrote: »

Gee, it's a tight spot alright.
Any idea who inserted that or when/ why. Are you original owner.
BTW you missed one pix from outside. Is this a semi or detached and I don't see why cannot a slot be cut from outside if it's not on a party wall.
To me a slot is still best and safest way rather than trying to use cutting torch from underneath unless you know some smallish circus worker types.

Look at the first pic, I have drawn the location of the flap onto that.
Looking at it from the front, there is the chimney itself which is concrete, blocks and clad entirely from stone. You would have to cut through 2-3 feet of that. No chance.
On the other side is a room and a wall, so more to cut there.
The idea to call out a builder and cut a massive hole into a wall or the chimney breast is insane, this would be a very substantial job and cost thousands.
On the outside, all you can see is a small chimney on top of a roof.
No, not original owner was someone who knew everything about building a beautiful looking house, but not the first thing about building a practical house.
Imagine taking a very thick and sturdy metal flap and building a chimney around it, then clad it in solid stone and build a house around that. That chimney flap is like it's the very center piece around which everything else has been built.
Here's a pic of the acrow:

braddun · 20-12-2014 9:34pm

http://www.dummies.com/how-to/content/how-to-fix-a-stuck-fireplace-damper.html

dr.fuzzenstein · 20-12-2014 9:50pm

braddun wrote: »

http://www.dummies.com/how-to/content/how-to-fix-a-stuck-fireplace-damper.html

All good suggestions, however:

You can clean a dirty or rusty damper with a wire brush along with lots of elbow grease.

It's 3.4 meters up in a space a midget couldn't get into. So that's a non-starter

slide a short length of pipe — about 20 to 24 inches — over the damper handle (this extends the damper handle); then beat on the pipe with a sledgehammer to break the damper loose

Look at the above post, there's an acrow that's bent like a straw. I also have done the above, with no results. Another non-starter.

When the damper is operational, work it back and forth while applying a high-temperature lubricant at all the joints and moving parts. When it’s clean and in good working order, spray-paint the damper with a black high-temperature paint to prevent future rusting.

I do not plan to get the flap operational, it has to go because I am installing a a stove.
Thanks for the link, but sadly nothing applicable in there.

whupdedo · 20-12-2014 9:58pm

Hi op, what distsnce is the flap from the top of the chimney outside ?

dr.fuzzenstein · 20-12-2014 10:14pm

I'm guessing about 2 meters. All this through a regular diameter chimney pipe, so can't get at it from there either.

What I am going to do is to take the bent acrow, cut the bent bit in two and insert a metal spike I have lying around. This is about a 1.5 meters long, a few centimeters thick and solid steel.
This will concentrate the force of the jack on a small spot, this should (fingers crossed) hopefully bend or break the flap.
After that, the only way would be a gas torch tied to a broom stick. I will invest in a fire extinguisher for that...

whupdedo · 20-12-2014 10:30pm

If you could heat the plate with a felt layers torch, they're about a metre long and your reach is another metre, I mean really heat it, get it really reddened up and that might expand the working parts and therefore free up the flap, i use heat on all stuck steel parts I come across and it rarely fails to work

shedweller · 20-12-2014 10:35pm

Maybe get a long pipe and make and end on it that will go into a drill. On the other end do the same but for a hole saw or drill bit. Hold it solid with grub screws. Then you have a two metre drill bit or hole saw. Establish where the flap hinges are and attempt to drill them out from above. The flap should feck off then with a few belts of a pipe.
Something also occured to me. Could there be stops on the frame of the flap to stop it going past closed? You may have been pushing against those stops. If so then push up at the end where the stop is under the flap.
This could be like the thread about the safe yer man had in his shed!

Edit: i just looked at the pic of the flap taken from the roof. It does look like a frame going around the flap and all the way too by the looks of it! So maybe the whole flap opens downwards?? Try beat the flap down from the roof with a heavy pipe. Safety first of course!

dr.fuzzenstein · 20-12-2014 10:41pm

Thanks about the two above suggestions. The torch has already been considered but the drill idea is a new one. The problem is, from above there is no chance to get at it, but from below it might be possible.
The torch is being sourced as we speak.

dr.fuzzenstein · 20-12-2014 10:45pm

Thanks shedweller.
The flap is a butterfly valve, so swivels at the center. I do know which side opens.
I will attack with a spike and a jack and after that a drill and a torch.
From above its not happening, the hole is too small, you can't get anything down there.

I do remember the thread about the safe, that was awesome. Doesn't matter if there was nothing much in it, sometimes the journey is the destination.

Kristopherus · 20-12-2014 11:21pm

dr.fuzzenstein wrote: »

Thanks about the two above suggestions. The torch has already been considered but the drill idea is a new one. The problem is, from above there is no chance to get at it, but from below it might be possible.
The torch is being sourced as we speak.

Is there any way you could track down the builder. It may be a long shot, but it may also save you come sweat and maybe tears. There may be a simple enough way of loosening that flap. Did the previous owners use it? IMHO you should make as many enquiries as possible. If you found out the manufacturer of the flap, it might be useful. Is tipping up (or down) the plap leaving you enough room to get a flue up?

dhog4n · 20-12-2014 11:33pm

Have you tried looking down from above? If you can get a camera down the chimney you will be able to see any blockage which may be causing the problem. If the flap is intended to open upwards, anything more than a few inches of mortar will make it practically impossible to force open from below.

The reason I suggest this is that it sounds very much like there is a mortar blockage. It is common enough for wall cavities to fill up several courses high at the bottom with mortar droppings during hasty construction and this could have happened during the construction of your chimney. Clearing or drilling through this will be much easier from above or from the side.

shedweller · 20-12-2014 11:40pm

Ah yes i see it now i think. It looks like the hinges are on the short sides. The frame edge i saw only goes around one long side and half of each short side.

dr.fuzzenstein · 21-12-2014 1:24am

shedweller wrote: »

Ah yes i see it now i think. It looks like the hinges are on the short sides. The frame edge i saw only goes around one long side and half of each short side.

That's the stuff!
Yes, the hinges are in the middle of the short side of the flap, it operates like a butterfly valve.
There is no blockage, as the flap has loosened somewhat and I can see daylight.
With my repaired and weaponised acrow I'm sure I can force the flap.
Tomorrow I'm being dragged shopping, so more early next week.

dr.fuzzenstein · 31-12-2014 12:27am

An update!
A neighbour came by with a friend and they climbed up on the roof with a sledgehammer and a rope.
They then repeatedly dropped the hammer onto the chimney flap until it opened.
So at least it's open now.
I now know that all the piping I bought is wrong and will have to go back.
I assumed that there would be piping just above the flap, but there isn't, the chimney is built square all the way to the top, with a short pipe section.
So the new plan is to exchange the sections I bought for flexible piping and somehow wangle that down the chimney.
Pics to follow.

shedweller · 31-12-2014 12:38am

Good progress! Yay! Will the flexi pipe go past the now open valve?

dr.fuzzenstein · 31-12-2014 10:12am

Well, that remains to be seen, have a look at the pics.
I originally assumed that the chimney was square up to the flap and then there should be pipes.
As you can see, it's square all the way to the top. My neighbour said he hasn't seen a chimney built like this in a long time.

The flap is visibly bent from my earlier attempts at getting it out of the way.
If I can't squeeze flex pipe past it, I will still have to get an oxy acetylene cutter.
And I have to hurry, there's a draft coming down that chimney that will cut you in two, the living room is not a nice place to be, even with the heat going non-stop.

Robbie.G · 31-12-2014 11:32am

Depends on what you want to do with chimney if you want an open fire the liner must be 200mm if you intend to have a stove the liner must be 150mm
Either way your going to have to remove the flap and line the chimney

dr.fuzzenstein · 31-12-2014 12:11pm

Robbie.G wrote: »

Depends on what you want to do with chimney if you want an open fire the liner must be 200mm if you intend to have a stove the liner must be 150mm
Either way your going to have to remove the flap and line the chimney

Removing the flap is the tricky bit.
I am installing a woodburning stove, so will see what my options are with flexible pipe. This should not require the chimney to be lined.
Other option would be flexible pipe and line the chimney with rockwool insulation.

edit:

I had something like this in mind:

https://www.youtube.com/watch?v=02P1PGqsUhU

antiskeptic · 31-12-2014 2:12pm

dr.fuzzenstein wrote: »

Well, that remains to be seen, have a look at the pics.
I originally assumed that the chimney was square up to the flap and then there should be pipes.
As you can see, it's square all the way to the top. My neighbour said he hasn't seen a chimney built like this in a long time.

The flap is visibly bent from my earlier attempts at getting it out of the way.
If I can't squeeze flex pipe past it, I will still have to get an oxy acetylene cutter.
And I have to hurry, there's a draft coming down that chimney that will cut you in two, the living room is not a nice place to be, even with the heat going non-stop.

Have you tried jacking it in the middle of the flap so as to bend the axle and perhaps pop the end of the axle out of it's locating hole? I can't imagine the axle is fixed particularily robustly in the frame: perhaps a circlip or split pin or in all likelihood, nothing at all - simply a round bar inserted in a hole in the frame.

Stuck chimney flap

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