PH Hearth requirements...

[Slow1]

Sorry if I somehow missed the whole thread on this. I don't see how I could have, yet I also don't see how it could have been up on WS's blog for so long and not discussed here

Anyway, it seems that they have published the updated hearth requirements. Now being self centered I'm trying to figure out if I meet the .40 requirement or not. Their table lists "Durock next gen" in the cement board pile, but not any other "Durock" which makes me wonder what mine is ("classic Durock?") and of course, what the value for it may be.... somehow I imagine I'm in for disappointment here, but...

Anyone want to break the bad/good news to me?

 

[Waulie]

There was a thread on it.

https://www.hearth.com/econtent/index.php/forums/viewthread/82608/

I believe the original durock had a r-value of 0.26 for a 1/2". I do find this quote from Woodstock a bit curious:

"We had additional UL test conducted with the radiation shield in order to facilitate installations on hearths with R-values of 0.40 to 0.80 (typically 1/2†cementboard or equivalent, covered with 1/4†stone or tile). These hearths were recommended for decades by various manufacturers in the hearth industry."

Typically, a half inch of cementboard and a 1/4 inch of tile will not have an R-value of 0.4. The only way it will is if it is NextGen. They seem to be saying (without saying it cause they can't) that the typical hearth used for decades would work fine. However, most folks with this setup will not meet the r=0.40 minimum.