Hearth pad, hearth board...etc...

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
  • Super Cedar firestarters 30% discount Use code Hearth2024 Click here
Status
Not open for further replies.

suprz

Member
Sep 24, 2012
219
Rhode island
My Jotul tdic came with a "hearth pad" i dont know if the owner built it, but i can tell you that it has at least a 1 1/2 inch thick piece of plywwood covered with cement board, then covered with tile. It must be around 3-4 inches thick. It is heavy as all h3ll too! My wife wants to build our own instead of using this one, which is ok with me! My question is that i cannot find what R value my stove requires underneath it during operation, and how to calculate the r value of a 1/4 inch piece of plywood and standard cement board (durorock?) and tile would be. I want it to be thin, but safe.

I have all the tools to build it, just dont know what the minimum thickness can be and the best materials to use
 
You'll want a stiffer piece of plywood to mount the Durock NexGen to for a stable tile base. I would use 3/4". 1/2" Durock NexGen is r=.39, regular cement board is R=.26

Here's a good table of common materials R value.

http://www.chimneysweeponline.com/horvalue.htm
 
http://www.jotul.com/FileArchive/Fi...s and inserts manuals/Jotul_ 3TDIC_2_0394.pdf

If I am reading this right . . . and this is your stove, it appears as though there is no actual number for the R value . . . or at least they do not give a set number . .. but they do require Durock or a cement board of similar construction at least 3/8 inch thick and then you can put tile, stone, etc. on top of that if you so choose . . . or you can go with the pre-made hearth if it has a safety mark such as UL or FM. Of course the hearth must also be 18 inches in front of the stove and 8 inches along the sides and back and be a minimum of 38 x 43 inches. See Page 5.

As BG mentioned there is a great chart showing the R values . . . and also as he suggested you will want something thicker than 1/4 inch plywood to mount your tile/stone, etc.if using plywood as you don't want any flexing. I also think you'll find that plywood in itself does not offer much in the way of R-value since it is combustible.
 
Well, the wife (or as i call her...THE BOSS) wants me to build the hearth for the stove. We are thinking of the 38x43 dimensions, and i will use 1/2 ply and 1/2 Durorock next gen and tile. We are thinking about using the tiles that look like river rocks, but i have concerns about the feet of the stove and the stove wiggling. Thie hearth will be going on top of oak flooring. And according to what i have read and the chimney installers / stove installers. That should be plenty of R value for the floor. Now to go look for tiles.. Oh yeah... My local Lowes only has durorock next gen in 36 x 60 sheets, so i guess i will have to get 2 sheets and i have to get a permit for the chimney install that is happening on 10/29
 
Go 3/4" plywood. The cost difference is negligible but the rigidity is substantially more. Or double up on the Durock NexGen layers.
 
Status
Not open for further replies.