Installing an open fireplace without a stone constructional hearth

[dominoman]

I hope I don't get shouted down for just suggesting this...

I'd like to install an open fireplace in the lounge to replace one that was bricked up many years ago. The original constructional hearth inside the fireplace remains, but the one that reaches out into the room was smashed out when the last owners installed wooden flooring. The wood flooring now goes right up to the wall where the bricked up fireplace is.

Installing a new construction hearth would be expensive and involve a lot of work. Instead, could I lay a thin bed of mortar on top of the wood, and then lay a new decorative hearth on top of that, then fit the fireplace inside the opening as normal?

I know this wouldn't meet current building regs, but there is another replacement open fire in the house that is built this way and is fine. The hearth never even gets particularly warm.

Thanks for any advice.

 

[dominoman]

Ok. So no replies - which I take to mean this guy is so dumb that this doesnt even merit an answer. You're right.

So I am definitely going to do this properly and have a contsructional hearth built. but to save money I'd still like to do it myself. I've read up on the building regs, plus a useful article here: http://www.stovefittersmanual.co.uk/articles/hearth-regulations/

Does anyone have any advice on how to actually build it? I have a 4 foot void underneath so how can I suspend a solid concrete slab from my wooden floor?

Thanks anyone if you have any ideas or a link to how to do this?

 

[theprinceofdarkness]

Its a bit of an odd problem. The problem with hearths is that people stand on them, so they have to be very robust. If you build your hearth off the existing floor, then it will certainly crack in line with the front of the chimney breast unless some local reinforcement is used.
You say that the original hearth has been removed complete with its four feet high supporting brickwork, does not seem right to me. it could be that it was cast in situ along with your neighbours.
Go and talk to your fire supplier. It would seem that my SIL is laying a concrete hearth (to be tiled) on a board that sits on his floor boards with some sort of flexible glue. Its so his laminate floor can end just under the concrete. this told was to him by both the fire installer and the tile supplier. Sounds iffy to me.
Frank

 

[dominoman]

Thanks. I will take some pictures as soon as I have removed the rest of the opening and see if that helps with ideas. Will also ask my supplier, as suggested.

There's definitely no remnants of the old hearth. I've been under the floor there and checked.

 

[Lower]

If you don't want to build a proper hearth down to ground level, do it the same way as they used to do it for upstairs fireplaces. Create a box supported on joists that you can pour your hearth into.

 

[dominoman]

If you don't want to build a proper hearth down to ground level, do it the same way as they used to do it for upstairs fireplaces. Create a box supported on joists that you can pour your hearth into.

Thanks. Yes, that's what I was thinking would be easiest. Have you seen any design or advice online anywhere on how to do that? I am fairly competent but don't want to make a schoolboy error!

Not sure if I just make a box and pour it in one go, or layers? How best to fix it to the joists. What mix to use?