Cement board (and tile) beneath wood stove

[bkoltai9]

Hi guys. Thanks for your help with everything so far. My project is moving right along.

My stove BEC95 has specific spatial requirements for the underlayment and specifies the following with regard to materials.

[This heater has been designed to prevent excessive temperatures on the fl oor beneath the heater. It is important, however, that a
combustible fl oor be protected by a 3/8 inch minimum thick noncombustible inorganic millboard having a thermal conductivity of k=0.43 BTU/ft./in./hr./°F or a listed fl oor protector beneath the heater extending beyond the heater as shown by fi gure 5. ]

I have browsed the forums and II understand k-value is thermal conductivity and I guess better materials have lower numbers? I see something called micore is recommended but it's not sold at the big orange box.

My options at the local home Depot are durock, hardi-board, and wonderboard lite. Will any of these meet specifications or do I need to be looking for an alternative?

Thanks again for your help.

 

[jetsam]

I think that's about 0.25 BTU/h∙ft∙°F.

 

[bkoltai9]

I think that's in metric. Can you tell me if it meets the specifications?

Edit: okay I see your comment. I guess that is adequate to meet these specifications?

 

[bkoltai9]

I find this from the home Depot website. Is looks to me like k value is 1.27? Am I reading this wrong?

 

[bkoltai9]

I'm still not entirely clear on this. If anyone else can chime in with an answer, I appreciate the help.

 

[bkoltai9]

I have an idea about this and I'm still looking for someone to confirm that I'm on the right track.

Stove requires 3/8" thinkness k=0.43. It doesn't say anything about r-value, but I can use the power of math and determine that R= 0.375" / 0.43 = 0.872 is perhaps the actual specification.

Given durock's listed k-value 1.27, I could once again use the power of math and determine minimum thickness = 0.872 x 1.27 = 1.11" durock.

Will three half inch sheets of durock suffice and be legitimate? Do I have this right?

Thanks again.

 

[Mech e]

I have an idea about this and I'm still looking for someone to confirm that I'm on the right track.

Stove requires 3/8" thinkness k=0.43. It doesn't say anything about r-value, but I can use the power of math and determine that R= 0.375" / 0.43 = 0.872 is perhaps the actual specification.

Given durock's listed k-value 1.27, I could once again use the power of math and determine minimum thickness = 0.872 x 1.27 = 1.11" durock.

Will three half inch sheets of durock suffice and be legitimate? Do I have this right?

Thanks again.

Your math is correct. Two sheets of the 5/8" might be less expensive.