Yeah, I had to special order it, but it could be gotten through a local lumberyard (Springfield, MA).

I called several and they all thought I was nuts. They knew what sheetrock was, they knew that USG made sheetrock, but they wouldn’t source a sheet of some other USG product. I could have bought a pallet at one place. 48” tall pallet-1/2 sheets-96 sheets-75$ per sheet= way too much money. Most people thought I was nuts at the mention of micore. Even the people that make the preman’d stove pads.

But this thread is about the cement boards and I will admit that I used wonderboard from HD which I assumed was an identical product to durock. Every layer of the wonderboard except the very bottom has a healthy coat of thinset mortar on it so the fibergalss stuff is not exposed. The wonderboard cuts like plywood with an abrasive bit on my circular saw. Dusty yes. Easily cut with precision- yes.

I wanted to get it because I want as thin a hearth board as possible, and with the Micore K value, I only need 1/2”, with clay tiles (which provide almost no insulation) on top, to meet my stove’s requirements. I actually could get the necessary value with 1/4” Micore, but I don’t believe that it is available. I don’t know what the distribution problem is. I checked on the USG site and they listed distributors in Redmond and Spokane, so I don’t know what’s up with that. They do list stoveboard core as a recommended product usage. I’m not sure why it has such a high K value compared to Wonderboard, etc. Perhaps it is made with air-entrained concrete?

“I checked on the USG site and they listed distributors in Redmond and Spokane,”

Exactly. A distributor buys lots and lots of pallets and distributes them. What you need is a retailer. I thought I would be smart and call the distributor to try and find the customers. No dice.

dmt5000 - 12 September 2007 05:04 PM

I wanted to get it because I want as thin a hearth board as possible, and with the Micore K value, I only need 1/2”, with clay tiles (which provide almost no insulation) on top, to meet my stove’s requirements. I actually could get the necessary value with 1/4” Micore, but I don’t believe that it is available. I don’t know what the distribution problem is. I checked on the USG site and they listed distributors in Redmond and Spokane, so I don’t know what’s up with that. They do list stoveboard core as a recommended product usage. I’m not sure why it has such a high K value compared to Wonderboard, etc. Perhaps it is made with air-entrained concrete?

The Micore 300 I have is not made to have tiles cemented directly to it. If I was you, I would add a 1/4” or Durock to the top. Then you have a cement board to adhere your tiles to.

Micore has a much higher R-value because it’s a TOTALLY different substance.  Durock, Wonderboard, Hardiebacker, etc. are Cement boards, made with concrete.  Micore is a CERAMIC FIBER product, more akin to fiberglass that has been compressed into a mat.

It’s good stuff, hard to find, somewhat expensive, but very useful.  When planning your hearth though, it is worth noting that one should not use it by itself - the stuff is a bit “squishy” and is not suitable as tile underlayment, as tile requires a VERY rigid surface.  Best practice is a layer approach w/ one or more layers of Micore, followed by a layer of cement board with the tile on top of that.

See the Wiki article (which I wrote most of) HERE for more details.

Gooserider

Try this stuff http://www.unifrax.com/PRIUS07.NSF/ByFormNo/C1210G3/$File/C1210G3.pdf It is UL recognized for floor protectors.  Will also require cementboard for structural integrity, but vastly reduces heat transfer.  Data page is here: http://www.unifrax.com/web/UnifraxHome2.nsf/AllDocuments/FEC07F2962C8450185256C3E0060038A?OpenDocument

They will ship anywhere in the US.  I believe the board material is made in Indiana, even though the sales office is in NY state. (edit) Board over 1” is made in Indiana and less than 1” is made in Tonowanda NY.  And as I have said before, Unifrax is quite a nice company if you’re the little guy.  If the Min order qty is a problem, give the folks in NY a call and they may find a smaller qty to get to you.

Thanks, Hog and Goose, for the tip on adding a cement board layer for the tile base. No way I would have known about it otherwise.

I’ve used both Hardibacker and Durock. Based on ease of cutting alone, I would never go back to Hardibacker. Durock all the way!

How’s wonderboard for cutting?

Cutting wonderboard was easy in a straight line with an abrasive bit in my circular saw. Cutting holes was pretty easy by drilling smaller holes around the perimeter and then knocking out the center. I then nibbled the perimeter smooth with pliers.

The stuff is heavy though at 96 lbs per 3x5 sheet.

Note on cutting Wonderboard, Permabase, Durock, etc.
If you read the directions sticker stuck to the board. It clearly states not to cut with a saw, grinder, etc. The stuff in there is not good to breathe.
The directions on mine specifically said to cut with a utility knife or similar. Exactly what I did, and worked perfect. And no dust mess, power cords, or power equipment needed. Just score with knife and snap. Pretty much same procedure as cutting drywall. Just a suggestion.

Uh oh, I may die soon.

Better you than me

I cut all my hardibacker with a saw, much faster. Just wear a good mask and goggles, the dust will dry out your eyes bad. And hell it cant be any worse then the pack of smokes I take in a day.