Opening up fireplace

[oldbutnotdead]

Enjoy. Do remember you need to find the original arch before you start pulling too much brickwork out- if you're unlucky and it's not there/falling to bits then time to think again....

 

[tell80]

OP,
Its best you decide exactly what you intend to do with the opening?
Whatever, its always best to work to determined fireplace opening dimensions of ht, width & depth.
If an appliance is a possibility then Mfr's supply the install dimensions necessary.

Your best bet is to remove all the c/b face wallpaper, and then knock off all plaster back to brickwork but stay 50mm away from outside corners, and only go up about 600mm above the conc lintel.
Then post a pic with the proposed opening marked on the bare bricks with chalk or crayon.

Your pic shows the hard metal tail of a flue liner - so, perhaps you still have a hard walled flue liner or a flexi SS flue liner remaining in the flue.
I guess that the board you've seen is a flue register plate - ignore it for the moment.
Likewise, leave out the elec and gas for now.
But take down the TV away from dust, and any vibrations.

 

[Hennah]

Thanks, will continue hacking tomorrow.
The space isn't for anything fancy, just a set of nestle tables with a new, larger Tv on the upper part of the breast wall replacing the one in the photo. The problem is making the fireplace big enough for tables whilst keeping it central and symmetrical below the TV, this problem is exacerbated by the extended right hand side from the plasterboard box extension.

 

[tell80]

No matter what you intend you will still need dimensions to work to.

Any RH plasterboard boxing-in would, as you say, have been for plumbing pipework to & from the back boiler. -
This info implies that the existing fireplace opening is central to the masonry chimney breast, which agree's with the position of the flue.

Why not remove all the boxing and its framing, & have a gas qualified plumber come in, and remove all redundant gas and water piping back to original branch off's?
You dont want any live gas pipe left redundant, neither do you want any water dead legs left connected.



Some of the brickwork you see, including the back wall bricks, is infill. Brickwork above the conc lintel & below the original lintel will also be infill.

The front hearth will typically be approx 50mm above FFL - is the front hearth remaining?
What is now the back hearth was superimposed on the original back hearth.
The original back hearth is level with the front hearth surface.

 

[Hennah]

The boxing on the right is empty save for a pipe at the very top which is the mains gas pipe running to a combi boiler upstairs. The pipe left the top right of the chimney breast at an angle so the easiest way to conceal it and give a tidy finish was to box it in from top to bottom so removing the boxing isn't really an option.
The dimensions of the fireplace will be dependant on where the right jam is as I will open it up as wide to the right as possible in order to be able to make the cavity central taking into account the boxing. So rather than measure the internal dimensions of the chimney area it will be based on the external breast dimensions that will be visible, eg, 40cm wall remaining on the right so 40cm wall remaining on the left.
I intend to have the pipes and flu parts that have been exposed within the breast cut back, I needed to get a gas Safe plumber in to sort the gas pipe. I planned then, once all cabling is done for the TV and a double socket placed down in the chimney recess, to block the chimney and seal it before plastering the back, sides and breast wall for painting.
This will all depend on finding another lintel and hopefully original fire jams to permit me to widen the fireplace to the right to compensate for the boxing.

 

[oldbutnotdead]

AHH, tricky. The breast is never going to appear central to the wall unless you put some dummy boxing on the left-hand side to match. You can centralise the fireplace in the breast by putting a fake infill in the left-hand side but that'll reduce the width available.
Opening up the right-hand side would be tricky. You'd need your supporting wall under where the boxing is now, which would mean going through the floor and down to subfloor for some support. You'd then need something like a chunky steel plate to transfer the load from the existing side wall to your new side wall (plate fixed to back wall or set into it, front edge of plate supported by new lintel). A fair bit of work....
I'd be looking at alternatives for the gas pipe myself, since you need to get someone in to sort the capped pipes I'd advise asking them instead about any options that would allow you to ditch the existing (right-hand) boxing and thus recentring the hearth in the room without some potentially expensive and intrusive engineering work

 

[Hennah]

I'm hoping, overly optimistically that if the right jams are over a bit more to the right then I will do as you mentioned, putting a fake infill on the left. The fireplace will be narrower than it was originally built but wide enough for my purpose whilst appearing symmetrical. If this isn't an option then I will probably box it all back up. Keeping everything crossed. Anxious to get home from work and crack on with it to know one way or another

 

[Hennah]

A thought that has only just occured to me (me being 5 steps behind everyone else). If by some miracle there is a supporting jamb where I hope and I can remove the bricks between the centre opening and said jamb, would this mean that I would also have to remove the newer lentil and consequently all bricks between the new lentil and the original one?

 

[Hennah]

Ok, a bit more hacking away has, I think, revealed where the original arch was, can you check the picture and tell me if I'm right or deluding myself?
I've marked in red what I'm hoping is the supporting structure and marked in blue where I want to extend the fireplace to. Does this seem reasonable?

 

[oldbutnotdead]

Oh that's a bit disappointing. Looking at that pic (especially the brickwork above the new lintel that you've exposed) it looks to me as though the right-hand return is actually original and brick and a half rather than brick. The soldier course above your red line looks a bit flat to be capable of taking any load on its own (unless there's a lump of steel hidden under there that we can't see). Just below the red line- is that the remains of plaster yet to be hacked off or is it a lump of concrete?

 

[Hennah]

It's a big lump of concrete, this isn't sounding good , just 4 inches away from succeeding

 

[oldbutnotdead]

Indeed not. Chopping out that half course (your blue line) would leave the new lintel and that large blob of concrete (and probably the rest of the front of the chimney) not particularly well supported, as well as removing support from the right-hand wall (if you peer up the chimney you'll probably see some corbelling starting about the height of that soldier course- thats being supported by that uncommonly beefy side return).
So, options.
You might still find an arch above that soldier course but I'd be surprised, those soldiers on edge look to me as if they were a finishing edge.
To do your planned opening up is going to be a lot more engineering without an arch in place.
I'm a bit suspicious of that lump of concrete- as it is (supported by new lintel) it's fine, not sure how much load it would take if you removed the new lintel.
Have you got a magnet you can wave around that soldier course and concrete lump (see if there's any metal in either).
If the plaster isn't being a pig to remove I'd be tempted to keep going upwards just on the off chance that there's some structure further up...or you could just cover it up and forget the whole plan cos your original little job is turning into quite a big one

 

[Hennah]

Tried with a magnet, either it's not strong enough or there's no metal so I'm going to forget extending the fireplace. I'm going to call a gas plumber out and see if there's a way to re-route the gas pipe that is at the top of the boxed area, if there's a way to chase out some part of the breast to route the pipes up into the ceiling space and join it up there then I can remove the boxed in section which will centralise the fireplace. It'll mean redoing the coving and some ceiling repairs afterwards but I was planning on having the ceiling plastered smooth anyway and the coving work isn't difficult.
Thanks again for the advice, it's disappointing it hasn't gone smoothly but hopefully the job can be salvaged

 

[oldbutnotdead]

Probably a wise call. One bonus of that return being so thick- you can do a deep chase in it to hide the gas pipe
If you do bury the gas pipe, take some pics (or measurements) and stick them by the gas meter as an aid for the next person who starts hitting things in there

 

[Hennah]

Quick update, a gas Safe engineer is going to embed and protect the gas pipe in my chimney breast wall tomorrow, trying to get quotes for a plasterer to replaster it all once the electrics are done. Only had one quote for plastering so far and it was eye watering so I'm hoping the others are going to be more reasonable.