1st Floor Hearth removal/replacement

[civhback]

Hi, hoping for a bit of advice on sorting out a 1st floor hearth. It appears to be a concrete slab a couple of inches thick placed over some rubble. Hearth had broken up and wasn't level and I'd like to sort it before laying down new carpet. What's the recommended way to sort this? Seems to be either a) dig out remaining rubble, add in joist support on back wall and then floorboard over or b) or repair it by re-laying rubble, pour self levelling concrete to floorboard level.

Fireplace isn't going to be used as the chimney is on an inner wall and already been removed further up.

As an aside, how is this actually supported at the 1st floor level? Extends a fair bit further out than the fireplace below and struggle to see how it's weight is being supported?

Pic for reference and cheers for any help!

VicHearth

• civhback
• 3 Oct 2018

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[oldbutnotdead]

Can't see the pic.
Get rid of it- the concrete probably goes into the fireplace, stitch drill vertically along the line of the wall into the concrete to split it away from the fireplace then chisel along the line to crack it away. Lift it out, get rid of the rubble underneath, sister the joists (where they've been cut away to form the hearth) with whatever you like (25mm x 120mm rough sawn will do) then board over.
The hearth is mostly supported by the floor joists......

 

[civhback]

Thanks for the response, managed to get the picture working now as well. Cleared the slab and some of the rubble away but it looks to be framed in on three sides so can't really see a way I can sister the joists without cutting the frame away also?

 

[cdbe]

Here's mine done recently:

Before:

And after:

I took the breast out as well so a bit more making good needed. The bit with the sunken floorboards was what my hearth concrete was on. It's nothing structural - just building up to the right level to put new flooring on:

 

[SFK]

Civhback,
Agree with Cdbe.

I had the same in my house. I saw the pile of rubble as being a cheap thermal and fire proof material that the original builder installed 20yrs ago. In answer to your question, in my case this two builder buckets of rubble was siting directly ontop of the ceiling below. Its weight presumably okay for the ceiling that it was sitting directly on top of, as any extra load was then taken by the hearth stone onto the adjacent joists. So I would not recommend standing directly on the rubble or capping it with concrete and then standing on that as you may end up going through ceiling.

I removed as much of the rubble as I could, and put in Joists to bridge any gaps, and put new floorboards across the hole (in my case reclaimed boards to get correct (old) thickness, or use new floor boards or sheet with thin bits of wood on joists to bring up height).

SFK

 

[civhback]

Thanks both, appreciate the response and those pictures are really useful. Looks like I'll clear out a bit more and see what I find then go the joist route. May need a bit more help when I get to that point!

Cheers

Civhback

 

[bobasd]

the fireplace an hearth on the ground floor are supported off the ground.
your f/f hearth is probably trimmed with joists an noggins.

carefuly remove all the remaining hearth infill - careful not to damage the ceiling below the hearth.
thers no need to double joist - aka sisterin.

you can pin or hang the new noggins an drive a slightly over length noggin into the back wall
or drill,plug an screw noggins to the brickwork where support is needed.
then board across the hole.

remove the margin trim before boardin - thats the mitred edgin.

 

[civhback]

So bit of an update, carried on clearing the loose rubble that was under the slab, now down to a brick layer, with an interesting brick arch built which presumably goes some way to explain how the weight was being supported.

So question is now> a) carrying on going, dig/smash out the brick that's there, or b) Get some wood made up and put across across (as per my dodgy paint pic), remove the mitred edging and then just board over the top?

Fireplace Edit

• civhback
• 8 Oct 2018

Thanks!

 

[SFK]

Civhback,
Looks very good and tidy.
Your option B) looks good option.
Also rather than having joists from left to right, you could put two joists from front to back.

But when I did it I was wanting to make sure that there was nothing on the ceiling below, so that if I ever took ceiling down (or it fell down), or the joists I put in flexed I would not also get a pile of bricks in lounge below.
For me the front section of bricks was simply on top of my ceiling, there was no other load bearing at all underneath. And the back part was solid and loaded onto chimney below - so I did not touch that.

So as I wanted full thickness (or is that depth) size joists, and did not want joists to sit on bricks or ceiling below at all, I removed (from your front section) everything down to expose the ceiling . Then put in the front two joists a little bit above the ceiling below. At the back section I actually put a layer of concrete as I knew that the chimney was other side of bricks and wanted to make sure it was sealed and no smoke could get in to room above.

So I guess it comes down to what is downstairs. If the Chimney protrudes out downstairs to take in that front area, leave and do as you suggest. But if the front brick as sitting on ceiling, I would remove the front bricks and put in bigger joists. I would not touch bricks at the back as you may enter the chimney itself.

SFK

 

[bobasd]

the joists on either side of your hearth are supported by what?
they both seem to end by buttin up to the brickwoek?
remove all the bricks an the ceilin should be revealed..

wheres this arch you mention?

i previous mentioned be careful an now you want to smash out the hearth bricks?

i also mentioned no double joistin needed - none at all.

 

[civhback]

Civhback,

So I guess it comes down to what is downstairs. If the Chimney protrudes out downstairs to take in that front area, leave and do as you suggest. But if the front brick as sitting on ceiling, I would remove the front bricks and put in bigger joists. I would not touch bricks at the back as you may enter the chimney itself.

SFK

Thanks, thinks that's pretty spot on to what I've got and I'll be looking to do the same, remove the front bricks and then just put frame support and flooring ontop.

New picture shows the bricks as being part of the chimney breast downstairs, and then just a gently arch extending out - just seems to be rough cemented in place/on top of the front of the breast. (Bottom right of new picture is line of chimney breast).

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i previous mentioned be careful an now you want to smash out the hearth bricks?

i also mentioned no double joistin needed - none at all.

Sorry didn't explain my post properly! just the front section that extends out the front of the fireplace I intend to remove rather than the existing chimney!, existing joists are supported by chimney breast from downstairs, no double joisting - just framework to support new floor board.

20181010_201731

• civhback
• 10 Oct 2018

Cheers

Civhback