wonderboard...

[trailblaze]

i just got this email from the manufacturs of wonderboard...

"½” Wonder is non-combustible and it has an “R” value of 0.134 @ 75 degrees"


well i guess this throws my plans out the window...i'd need 2.5 inches of this stuff to make it slightly work...

however, the r value is at 75 degrees.... what about the temp under a stove.. would that R value raise or lower??

 

[begreen]

That doesn't jibe with what I've read, I wonder where they got that figure for that board.

Use Durock brand (by USG) instead. A 1" thickness will give you R .52, 1.5" = R .78.

 

[trailblaze]

i can't find any places around to purchase Durock.

maybe it's the temp factor? maybe at like 150 degrees it's .268 per 1/2 which puts it at approx .52 at 1 inch??

 

[begreen]

Do you have a Home Depot or Lowes nearby? Durock is pretty common.

 

[trailblaze]

i have multiples of both stores... they looked at me like i was nuts when i asked for Durock Cement board...although most of those workers don't know their left foot front their right...



i just got an email back from wonderboard... they say the R value will decrease with higher temps...

 

[begreen]

It sounds like they gave you the R value for a 1/4" thickness and not the 1/2" sheet. As long as you get the 1/2" cement board (not the lightweight Wonderboard or Durock) I think the R values are identical. Ask them why Durock is twice the R value for essentially the same product.

 

[fossil]

Well, here's another chart from a trusted source. My understanding is that wonderboard and durock, both being cement boards, are pretty much interchangeable. Rick

(broken link removed to http://chimneysweeponline.com/horvalue.htm)

 

[trailblaze]

i agree... something doesn't sound right about an R.134

i swear, dealing with people anymore is a pain in the butt..i am sooo frustrated right now

BeGreen.... i called the local Lowes... demanded i speak with the store manager, who personaly looked for the Durock brand and what would you know... THEY CARRY IT...

if i could have got this response the first time it would have saved me a lot of trouble...

i'm putting 3 layers of Durock down and being done with it...

 

[fossil]

...i swear, dealing with people anymore is a pain in the butt..i am sooo frustrated right now...

Hey...we're people. %-P Rick

 

[trailblaze]

not you guys... the people at lowes