Reopening bricked up chimney

[Kaymo]

Hi,
Currently in the process of trying to reopen an old fireplace. House built sometime in the 1800's, and the gable wall in question is probably a sandstone/whinstone mix.

I've pulled the plaster back to full expose the fireplace and was about to start removing bricks tomorrow but thought it might be good to get some advice on whether its safe to proceed or if there is anything else I need to consider.

Sorry the speakers are in the way a bit in the pic. I put these back on after opening up as I had a very important movie to watch!

This looks like it might be the lintel. Its certainly a single piece of stone and stretches the full width of the fireplace.

A slight concern about the state of the wall here at the base on the right below. Think this has been caused by dampness. The chimney had been closed up without a vent, and I think there was some rainwater ingress too (chimney is going to be rebuilt soon).

 

[Doggit]

Well, unless you've already started, I'd expose a bit more of the wall first, and see if there's a lintel above the bricks. You'll also be able to see what the upper part of the chimney breast is like, in the event of more extensive work being required.

 

[Kaymo]

Thanks Doggit, the lintel is the grey bit you can see in the first two pictures at the top just above the bricks and below the plaster line. Presumably sandstone but there was a lot of cement smeared on it from the top of the bricked up opening.

I did go ahead on Saturday afternoon, took the top bricks out first gradually until I could see that the lintel was whole from below, then worked down the left side as that wall seemed in better condition. Once I could get a good look in behind the bricks and could see it was looking ok, I had a smashing good time with the sledge hammer.

The lintel from below is quite a hefty piece of stone:

And the fireplace now fully open looks quite good I think. The question is what to do next. I think I will carefully chisel the cement off the sandstone and leave this exposed, with a wooden frame to edge off the plasterboard. Will have to get a hearth sorted obviously, as there is nothing there under the floorboards, will need to look into the requirements.

There appears to be a void under the stone on the right hand side, perhaps I will be able to just push some stone mixed with lime mortar into this. Think there has been a bit of erosion here with the chimney leaking for god knows how long before we bought the place, wood around here is rotten too..

One thing I haven't seen before is the sloping part pictured below. It has broken away to the left, but at the right is like there is a built in slope from the back wall to the front of the fireplace, can't think what the purpose of this would have been.

 

[Doggit]

Well done. Not sure on the slope either, but cut it out, use the ballast for the hearth, put in some cement with a waterproofer in it (getting a dpm won't be easy) and then lay whatever hearth you want. Cut out any rotten wood, and treat the wood and surrounding brick area just to play safe.

 

[bobasd]

why are you opening it up?
is tthe whole chimney or just the stack being rebuilt?the floor is suspendedyou say, have you been under the floor?suspended.theres prob a front hearth or fender wall under the wood flooring.
theres dampshowing prob from pentrating or maybe rising. can you put up a photo of the outside of the c/breast.
is the door on the right an outside door? weird anyway having a door slap next to a fireplace.does the c/breast have fireplaces in rooms above?
the flue or flues needs sweeping and smoke testing.
have you been on the roof and looked at the stack

 

[Kaymo]

Bobasd,
Planning to put a stove in. Just the stack, being rebuilt with new sandstone as it has been patched for decades by the looks of it and is leaking. The damp you can see is from water coming in the chimney, building up and seeping through from ceiling height in the room, where a loose brick and debris had lodged. The chimney had not been vented from the room and it had probably been taking in water there for years without any way to ventilate. I drilled a couple of holes in the wall a few months after we moved in to allow some airflow and the stink of dampness that came out was there for days but it is fairly dry in there now as it has now been vented for about 6 months.

Outside is a gable wall covered with cement render and harling. This is getting taken off at the moment, going to either get it put back to original stone, or re-rendered with lime or something breathable. While the scaffold is up and once the stack is finished I am going to sweep then drop a liner down.

I have been under the floor and there is no hearth. I was surprised by this but maybe it has been completely removed. It seems as though there is a joist running across where the hearth would be. I was going to check the regs and find out if it is possible to fit a raised hearth on top of the floorboards.

The door on the right is a cupboard, I think it gets called an Edinburgh cupboard and they are quite common around here and near to fireplaces. Only about 30cm deep. Pics of the stack below before the masons started on it.

 

[bobasd]

dont be certin you now where the waters coming from.dont cover up until youve found the cause.removing the render might show more. the wet stains look like they are outside the fire surround and maybe into the bit of framing and trim.
it looks like you have parapets on the gable verges. the copingstones need to project a little, like the projecti stones on the stack and should have drip throatins.
you need a HETAS or whatever Scotland has to give you some tips and maybe do the installation.

sweep and smoke all your flues use 2 people, 1 inside and 1 outside and then put a camera down all the flues to check ffor ddamage to sides and feathers.

 

[Kaymo]

Yes, the wet stains are at the side of the fireplace, but there was a stone and buildup directly above this point in the flue. It looks like the water was coming down the stack and collecting there, then seeping down through the brickwork at that point. There is a stain on the ceiling directly above. Although the harled render is loose the base coat underneath is completely solid in every place that it has been removed so far so the chimney remains the most likely culprit. We'll see anyway once the render comes off. No needed HETAS here, just need to meet building regs, although installers are usually HETAS registered. I will probably do the stove myself, i've plenty experience from industry working on furnaces, gas systems and the like, but will need to get a close look at the regs before I do anything. No real rush to do the stove anyway, the main thing is to get the liner installed while the scaffold is up.

The coping stones will might project enough once the render comes off as it is quite thick, but if new render goes on then will need to project further, or get a lead raggle to project. What are 'drip throatins'?

The feathers need to be rebuilt, they are hanging suspended in the stack and the sandstone is also a bit weak and worn away at points. Will see once the mason gets down a bit further but he is suggesting that we might want to consider dropping liners down all the flues, then filling the gap with an insulation/lime mortar mix. He thinks this might help to stabilise the stonework on the gable where it is weak and hold everything together.