Stone hearth pad base

[rpwalton]

So I'm using about a quarter inch piece of old slate chalkboard with the natural side up and flat side down as my hearth pad for my new wood stove.
I want to put something under the slate to cushion any irregularities between it and the floor.
Right now I'm considering cement board or Hardie board...
Any advice or recommendations?

 

[rpwalton]

OK, I see Hardie board is a type of cement board...
Is this the best thing to use under my big slate, or is there something better?

 

[Eman85]

I built my hearth up with framing under cement board then covered in rock.

 

[begreen]

Cement board is fine. Use latex-modified thin-set to bed it and take out irregularities.

Does the stove require an ember-protection-only hearth pad or more?

 

[rpwalton]

Cement board is fine. Use latex-modified thin-set to bed it and take out irregularities.

Does the stove require an ember-protection-only hearth pad or more?

Yes, ember protection only, no R-value required.

 

[begreen]

Yes, ember protection only, no R-value required.

Then it will be fine. Use a 1/4" notched trowel to create a thicker bed of thinset.