Question about insulating a hearth

[mvubike]

So here's the deal:
VC Intrepid with 3" short leg kit

I'm building a 12"Hx28"Dx34"W elevated hearth out of 3/4" cabinet board (essentially plywood). My plan was to use a layer of mineral board on top of the wood structure and then to cap it with a 29"x35" piece of 1.5" thick soapstone. The structure will be open in front to act as wood storage box.

Is that going to be enough insulation considering the 3" legs on the stove?
Even my stove guy couldn't give me a concrete "yes it'll be fine".

Thanks for any help!

 

[begreen]

Is this the Intrepid II? Does it have the bottom heat shield attached?

The minimum size for the hearth floor protector is 34" x 40" according to the manual.

 

[mvubike]

Is this the Intrepid II? Does it have the bottom heat shield attached?

The minimum size for the hearth floor protector is 34" x 40" according to the manual.

It's the pre catalytic VC Intrepid and it doesn't have a heat shield. The "hearth" I'm making is really just a fire box that will sit on a tiled area that is 36"wx48"d. Considering that the box will be off the ground enough to give me the clearance to flammables on the sides. The wall behind will have a 24guage steel heat shield and the back of the stove will have the required 9" clearance from that. The front lip of the Intrepid will only have a few inches of the soapstone hearth top extending below it but the tiled are will extend 20" beyond that on the floor.

My main question is wether or not the layer of 1.5" thick soapstone and a 1/2" thick piece of mineral board is going to be adequate to keep the wooden box underneath from being at risk. The edge of the soapstone will protrude a 1/2" all around so the wood will not be directly exposed to the base of the stove.

Hope that all makes sense. Thank you for any advice!

Best,
Matt

 

[begreen]

OK, that changes requirements. It sounds like you are following the manual. That would be roughly an R=.53 hearth. You could use a couple 1/2" sheets of Durock NexGen cement board in lieu of the mineral board if that is hard to find. Be sure that the sheet metal heat shield is open an inch at the top and bottom so that air can freely convect behind it and that it is secured with non-combustible 1" spacers. Short 1" pieces of 3/8 or 1/2" copper tubing work well for spacers.

 

[mvubike]

Great, that answered my next question... where to find mineral board cheap. I'll grab some Durock Next Gen.

Soapstone has really low R-Value I guess eh? Sounds like I need a .8 to be safe & 2 sheets of 1/2" Durock would be .78 total based on a quick google search. The soapstone should make up that final .02

Thanks for your help!

 

[mvubike]

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