Materials for a hearth

[samandothers]

I am trying to determine which concrete board may be best to use on a hearth build.  The hearth will be under a woodstove that requires an R value of .41.   I will use 1/2" of Micore 300 board to get an R value of about 1.0 which meets my need.  Vendor does not suggest using this to put tile directly on.  So therefore looking at concrete type backer boards.  I am looking at Durock backer or Hardie backer.  Any one have experience with either?

What I am reading is the Hardie may have more compression strength which is good since the stove will be heavy.  I can not find an R value for it.   The Durock has a R value .39 for a 1/2 inch but may not be as 'tough' as the Hardie.  Since the R requirement is met I may just go with Hardie as it seems more readily available.

[Ljohnsaw]

I've always used Hardi backer board.  I just like it better.  Just be careful with your screws when near the corners.  It comes in 1/4", 1/2" and 3/4".  The 1/2" is actually 3/8" thick.

[Ruffgear]

Personal preference I suppose, but I much prefer durarock over hardi. 

[samandothers]

Thanks guys for the response.  I have read the same type of responses on another forum, there is a split on opinions/preference.  I talked with the person that will do the tile work on the hearth.  I asked if he had experience with hearths.  He indicated he had put in hearths and had used both.   His preference is to use Hardie.  I decided to let him do the hearth using the Micore I'll supply and he'll get the backer for the tile.  

Thanks for input.