Fireplace Help

[garob]

I have an exsisting chimney breast which is 2.54m high x 1.46m wide and the fireplace opening is 1.2m high x 1.0m wide. I have a quarry tiled floor around the outside of the chimney breast which has been there for aprox 100 yrs. The tiles are 20mm thick and laid on a bed of lime and the ground underneath the tiles is compacted.
I want to build a new brick wall (2.54 high) on top of the tiles on the outside of the chimney breast and the new inner brick wall will replace and sit on the original inside wall of the chimney breast (1.2m high). I intend to use an oak lintel 14cm x 17cm x1.2m long.
My question is will the outer floor and inner fireplace floor be sufficient to support the weight of the bricks and lintel ?
Any help any one can provide I would be very grateful.
Cheers !
Gareth
North Wales

 

[Andrew Bodenham]

In essence you're talking about building a single thickness brick skin across the front of the chimmney breast, and a similar skin inside the fireplace aperture. Is that right? May we ask why? And you want to sit this on the quarry tiles which are sitting on compacted earth.

Well, it might work. It depends how well compacted the earth is. But it sounds like it wouldn't be a big job to lift a few rows of tiles, dig down a suitable depth and either drop in a mass concrete footing, or even something like a row of concrete kerbs bedded on mortar. The point of this is to spread the load into the sub-soil so that your new brickwork doesn't sink or crack.
Single thickness brickwork is about 220Kg/m^3, so you can work out the mass involved.

Inside the fireplace there should be a substantial thickness of concrete or similar forming the hearth, in which case I'd feel more confident about building off the existing level. Surprised actually that there isn't a constructional hearth across the front of the fireplace too - have you lifted the tiles for a good look?

You don't say what the construction of the original fireplace is, but you'd be advised to tie your new brick facing onto it, perhaps by using some screw-in wall ties that you should get in any builders merchants. This will stop your new leaf of bricks parting company with the old chimney breast at some point in the future.

 

[middi]

Victorian and Edwardian" upgrades" on a lot of 17th, 18th and early 19th C. chimneys were added to and restricted in the same way as you propose some show no movement and some others do, those that showed movement were plastered over and some of these showed cracks in the plaster and some didn't. Nobody can guaranty thet there will be no movement but it will help if the new bricks are tied into the existing every 3 courses.
I respect that it is your home and you intend to live in it the way it suits you, what I find difficult to understand is why the heck someone would want to "embelish" an original brick chimney by covering it with another layer of bricks.

Most of the question on this site usually are about how to remove added bricks and stop the original chimney from falling on their heads.

 

[Lime]

Victorian and Edwardian" upgrades" on a lot of 17th, 18th and early 19th C. chimneys were added to and restricted in the same way as you propose some show no movement and some others do, those that showed movement were plastered over and some of these showed cracks in the plaster and some didn't. Nobody can guaranty thet there will be no movement but it will help if the new bricks are tied into the existing every 3 courses.
I respect that it is your home and you intend to live in it the way it suits you, what I find difficult to understand is why the heck someone would want to "embelish" an original brick chimney by covering it with another layer of bricks.
Most of the question on this site usually are about how to remove added bricks and stop the original chimney from falling on their heads.

That is what I thought.
I wouldn't balance an 8 foot plus wall on the tiles alone, neither would I dig out the trench neccessary to support the wall.
It would have to comply with building regulations and would undermine the house and any newer structure like the fireplace.
.. I wouldn't use cement either.
I think the entire idea inappropriate and full of difficulty.

 

[Andrew Bodenham]

Perhaps if we let Gareth tell us a bit more about the thinking behind the project instead of just telling him that he's got it all wrong we might be able to have an interesting discussion about it.

 

[garob]

Thanks for all tyour comments up to now.
I should explain that the chimney breast was plastered by someone in the past with concrete and I have removed all of this. I had hoped to reveal some attractive stone or brick work but it is not very nice and consists of slate/stone and brick. So my
idea was to lay a new skin ( in reclaimed brick) around the chimney breast and on the inner wall of the hearth (by removing the original stone/slate there). I was going to tie in the new brick wall with ther other.
Gareth

 

[Gareth Hughes]

I know I sound like a stuck record, but it's probable that the fireplace was always rendered (even if its most recent coat was unsuitable cement). This is for the good reason that, as you say, the underlying structure isn't very attractive (and nor, in my and many others' view, is naked brick as an interior finish).

 

[another_richard]

If you want to add a single row of bricks to replace the existing untidy ones, why not use a stone cutter to "queen" the bricks (is it still called that?) essentially cut them down the middle and attach them. Less weight.

 

[garob]

Thanks for all the help
Gareth