Raised hearth

[JONXLR8]

I've completed my constructional hearth and am now looking at building a raised hearth a single layer of bricks high.

Untitled

• JONXLR8
• 19 Oct 2011
• 1

I've laid out the bricks to give an idea of how it would look, obviously I've got to do something about the gap in the middle, maybe cut some bricks down or turn two sideways (any other ideas?).

I've already got some NHL2 lime mortar which I bought for repointing the existing fireplace brickwork so I plan to use that for laying these new bricks.

What I plan on doing is laying these few bricks down then back filling with concrete up to the level of the top of the brick, then putting slate on top of that. I thought doing it this way would be easier than laying a load of bricks over the constructional hearth and more likely to get a flat finish.

Anyone agree / disagree? Any things I'll need to look out for. If i back fill with concrete first up to about 10mm below the level would it then be worthwhile doing the top layer in sand and cement (Hanson sand & cement mortar OK?) or Sika self levelling compound to give a smooth finish ready for the slate?

Just putting this idea out there to make sure I'm doing it right and not making life hard for myself. Any feedback appreciated, thanks.

 

[r896neo]

Using concrete brick to infill rather than poured concrete will mean you can tile after a couple of days rather than waiting a few weeks for the concrete to cure. Less of an issue for a one piece hearth

 

[JONXLR8]

Good call, hadn't thought of doing it like that.

The concrete bricks would obviously have to be on a bed of mortar but would I have to fill in between the bricks as well to make the pointing?

Also, as the constructional hearth is at the moment slightly lower than the solid floor (it slopes down towards the back of the fireplace). Would it be worth me putting a layer of sand and cement mortar or SLC down to level off before laying the concrete bricks on mortar first?

What do you mean by 'Less of an issue for a one piece hearth'?
I have access to some solid slabs of granite which I intend to cut to size to make a one or maybe two piece hearth rather than tiling.

If I did go for poured concrete rather than concrete bricks. How long should I leave the existing constructional hearth to cure before pouring the new stuff on top? I poured the constructional hearth last Saturday.

 

[r896neo]

No need for any extra base Just clean it well and then bed the bricks up on mortar to suit. As for in between just fire mortar in there too. I have done this in the past and tiled it 3 days later with 4inch quarry type tiles with no problem.

By one piece i meant a single stone slab cut to suit as you guessed. If you go for a pour fire it on anytime no need to let constructional hearth cure, but if you decide to go with tiles instead of your granite you'll need to give it all a month.

 

[Richard C]

Little tip; for continuity of your project & to be sure everyone knows what’s going on, it’s better to continue posting your original thread rather than start a new one; I’ve only just spotted it!

Can’t remember what sort of stove your having but for wood/multi fuel you can’t use a one piece hearth, it will crack. Be wary of using thin screeds over bricks, anything less than around 40mm is liable to de-laminate & crack, especially with high heat & you will need a month as stated. If you’re thinking of using SLC, check it has a suitable heat tolerance; with a log/multi fuel stove, you’re going to need something that will withstand at least 100 degrees & possibly up to 150, depending on the stove.

 

[JONXLR8]

Thanks for the replies both, yes I've got so many thoughts and questions running round my head I sometimes don't know whether to continue an older thread or start a new one.

That will teach me to proof read too, I've got access to slate not granite.

Correct me if I'm wrong but I thought the 'dont use one piece hearth' rule only applied to solid fuel open fires which obviously has direct heat as apposed to stoves which I imagine get extremely hot but not to the degree where it cracks whatever it's stood on? The stove we are looking at is a Town & Country Little Thurlow 5kw with 'log store' (basically on taller legs to make it fill our tall fireplace more)

http://www.townandcountryfires.co.u...eThurlow/tabid/62/language/en-US/Default.aspx

I do still have a big pile of the red pin hoe bricks outside that I cleared from the blocked up fireplace so I may as you suggest use a bed of mortar to get them up to the correct height so they act as a base for the slate.

I'll get there one day soon

 

[Richard C]

Correct me if I'm wrong but I thought the 'dont use one piece hearth' rule only applied to solid fuel open fires which obviously has direct heat as apposed to stoves which I imagine get extremely hot but not to the degree where it cracks whatever it's stood on?

No; in fact the temperature of a hearth with an open fire will most likely be less than one with a log or multi-fuel stove; unlike open fires, they don’t squirt most of the heat generated up the chimney & are much more efficient so local temperatures around the stove will be higher.

The stove we are looking at is a Town & Country Little Thurlow 5kw with 'log store' (basically on taller legs to make it fill our tall fireplace more)

I would advise you consult the manufacturer with regard to heat transfer; downwards will be less but it may still be more than you imagine!