Pouring the hearth

[barnesy]

Just about to start construction and have a queary on the hearth. I thought about building the stand 5 blocks high and using the top row of blocks as the formwork for the structual and insulating hearth. I would lay 4 courses, put down a fibre cement sheet then put the last course on top. The reo bar would tie it all together and keep it stable. Could i then just use reo mesh in the 2 slabs for strength???

[exceloven]

Re: Pouring the hearth

Barnsey, That is kind of what I did. It worked out well for me. Good luck.

Mark

[fil-ski]

Re: Pouring the hearth

Hi Barnesy,
I was thinking about using the same method. Four bricks high and placing an 18mm compressed fibre cement sheeting between the fourth and fifth block then pouring in the concrete.

Just wanted to know how you went with this.

[ThisOldGarageNJ]

Re: Pouring the hearth

thats pretty much what i did as well,, see pics

Cheers
Mark

[fil-ski]

Re: Pouring the hearth

That?s a little different to what I?m thinking. It appears that you set the formwork above the last layer of bricks.

What I?m thinking of doing is adding one more layer of bricks to act as the form work.

[fxpose]

Re: Pouring the hearth

For added security if I were doing something like this I would use narrower blocks (8x6x16) as the top formwork course so the entire slab perimeter would rest partly on the wider (8x8x16) blocks beneath.
But I guess with enough rebars extending into the blocks themselves, that's more than adequate.

[Neil2]

Re: Pouring the hearth

I agree with fxpose.

Unless your suspended structural slab is supported on the wall (2 inches should do it) it will shear at the wall face.

[fil-ski]

Re: Pouring the hearth

Just what I was thinking guys. First four layers of 390x190x190 Besser blocks then on the Fifth Formwork layer a 390 x 90 x 190 block. That’s 100mm of overlay on the slab.

The other option was to use decomposed granite instead of concrete, level, and then place 2” Calcium silica board then fire bricks on top. Might save some time.