Hearth Pad Cement Board - I'm Confused

[jtp10181]

Off the record I would say any of the ones listed are fine.

As a professional, I would have to say only the ones that are specifically tested as a non-combustible material should be used. It also happens that those ones have a slightly higher R value also, which is an added benefit.

 

[mkinsley]

FYI I know I am late to the party but I went here looking for information prior to building a hearth and wanted to see what everyone thought of DuraRock Next Gen. I would like to add for any other late comers that I bought some today in NJ 8 pieces of 3x5x1/2 and the sticker states its UL Classified in also in accordance with ASTM E136 Standard Test Method for Behavior of Materials in a Vertical Tube Furnace at 750 degrees C. That's hot. So I am thinking I yeah there is going to be some heat transfer. But I intend to use steel studs under the board to give 1.5 inches above my floor and give air flow. I intend to use double 1/2 Dura Rock Nex Gen board and then a tile upper. I cant see that failing.

 

[NVHunter]

FYI I know I am late to the party but I went here looking for information prior to building a hearth and wanted to see what everyone thought of DuraRock Next Gen. I would like to add for any other late comers that I bought some today in NJ 8 pieces of 3x5x1/2 and the sticker states its UL Classified in also in accordance with ASTM E136 Standard Test Method for Behavior of Materials in a Vertical Tube Furnace at 750 degrees C. That's hot. So I am thinking I yeah there is going to be some heat transfer. But I intend to use steel studs under the board to give 1.5 inches above my floor and give air flow. I intend to use double 1/2 Dura Rock Nex Gen board and then a tile upper. I cant see that failing.

I'm with you. I'm going to build my hearth almost in the same fashion as you. 3/4" plywood with 1/2" Dura Rock Nex Gen on top of it. I'm going with 1/2" slate tile on top of that. No metal studs though, just regular 2x4" studs.

Lopi Cape Cod's manual states:


"Floor Protection Requirements

•  Floor protection must extend to the sides, rear, and front of the stove (see “Clearances” below for minimum floor protection).
  
  
•  Floor protection must be non-combustible and at least .018” (.45mm) thick (26 gauge). "
  
  So, with that said, I think my material is 1" plus of non-combustible in material above the 3/4" plywood and well over the .018" thick requirement Lopi requires in their manual.
  
  I think this sound do.

If I get spooked then maybe I'll double up on the Dura Rock sheets to two, for an 1" thick base...