# Need help with hearth... it's gettin' cold!



## leezarrd (Aug 12, 2007)

Does anyone out there know how to get a .446 R value with the least amount of height (so it's not so high above my floor) for under my small woodstove? There will be 3/8 ceramic tile directly under the stove and I have to figure out what do put under that to acheive the .446 R value.... Any help is GREATLY appreciated... it's startin' to get cold out there.

Do you think it would help to raise the stove up on blocks to get it farther from the floor?


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## Ron6519 (Mar 28, 2007)

What is a .446 R value and why would you want this? Why don't you explain what you're doing, maybe that will help.
Ron


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## leezarrd (Aug 12, 2007)

Sorry for being unclear... and thanks for letting me know.

I have a wood stove that requires that the unit be placed on a "noncombustible floor protection equivalent to 3/8" millboard with a min. R value of .446". I am trying to do it with the least amount of height so it is not a "toe-stubber".

I figured a sheet of Durock with ceramic tile would be enough, but I find that the R value for the Durock is only .26 (it is not clear if that is for 1/2 inch or the thinner version, which I believe is 3/8 (?) ). I also thought maybe I could put the stove up on firebrick to raise it above the hearth, hence more air space....

Just found this interesting site - http://hearth.com/econtent/index.php/articles/k_values_what_does_it_all_mean
It appears Wonderboard and Micore 300 would work but I have not seen them in our area.

So the question is: What is the minimum height that I can build for my hearth and still be safe? Thanks!!!!!!!!!!!


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## leezarrd (Aug 12, 2007)

...or put in another way: what can I use to have a safe hearth with the minimum amount of height? And would raising the stove (it's only about 225 lbs.) up on firebrick (it already has a airspace under it so I would be increasing that space) be enough R-value to be safe?


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## so-elitecrete (Oct 27, 2007)

*you already have your answer,,,*

place your stove on a "noncombustible floor",,, reg brick's non-combustible last i knew,,, like touching a hot stove, everyone'll soon realize there's toe-stubbing opportunity in the vicinity,,, appearance'd be another issue &, probably, best resolv'd by the woman in your very fine home, right ?

2 sheets of durock'd be .52 if my arithmetic's right,,, hardibacker's the same & avail @ h/d in 1.2" & 3/8" thickness's.


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## concretemasonry (Oct 10, 2006)

Is this a building code requirement or an insurance company requirement?

Even if you meet the building code (the least you have to do to be leagal) does not mean you will be able to buy insurance at any price and may have to look for a different company.


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## fireproof (Aug 1, 2008)

*millboard floor hearth*

Hi,

I'm in the same boat as leezzard. We are installing a wood stove and we need to build our own floor hearth. We are unable to buy one big enough to suit the building code requirements. The building inspector for my town told us we could make our floor hearth out of mill board. I've found many web sites about people who used mill board, but not where I can buy it. I tried the local Home Depot, but they don't have it. If anyone can tell me how or where I can purchase mill board, I would be very grateful.

Thank you


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