Hearth Pad....

[Dr Bigwood]

HEY! I am so glad I found this site! It's helped me choose a wood stove make and model and it has guided me in the installation... Awesome!
My question is: How thick does a hearth pad have to be in order to be safe and within code.
I am planning on purchasing a Jotul Oslo 500. I want to build a hearth pad made out of ceramic tile or stone tile (natural materials).
My idea is to lay the tiles on a cement board with grout. The cement board will lay on my wood floor... Do the tiles have to be thicker than .25 in.?
Has any one used this type of hearth pad?
Is it safe. Within code?

Thanks

 

[crow]

I just finished building a hearth pad for my stove(hearthstone tribute).
The key for proper protection for your particular model of stove can be found in your stove manual.
You will need to see what all of your clearances need to be from combustible walls and materials as far a placement goes, and then the manual should also tell you what the minimum hearth dimensions must be. Following that , you will need to find out what the required R-value needs to be and what building materials(ie. micore, cement board, durrock, wonder-board, tile, etc.) are best suited for use in your hearth.

they also sell prefabricated hearth pads/ stove boards...that are UL listed. But it's nice to build your own so you really get the look you want, if you have the mind set for it.

I'm sure there are some seasoned wood-burners out there who can advise you better than I . Craig was especially helpful when I was completing my hearth.
Lists of R-values and K-factors differ slightly from source to source.

 

[Nokoni]

Jotul's web-site has manuals that you can download for each model. The manual tells you specifically what is required for the hearth.

 

[Hokerer]

Looking at the manual for the Oslo, your floor pad needs to have an R-value of 0.5. In comparison, my Hearthstone Phoenix needs a pad with R-value of 1.0 and a Hearthstone Tribute needs 0.6. The manual for the Tribute also has a table listing the R-values of some sample materials. In answer to your question, a half-inch of cement board (Durock, Wonderboard, etc.) is listed at an R-value of 0.2 and a quarter-inch of ceramic tile is listed at 0.01. This gives your proposed floor pad an R-value of only 0.21 which is less than the 0.5 that the Oslo requires. Looks like you need to do better than that.

 

[crow]

I ended up using multiple layers of wonderboard to acheive the desired R-value, followed by thinset and tile .
You just need to be sure that when you add all the respective layers r-values together , you end up with a total R-value that is equal to or greater than the requirement listed in the manual for your stove.