Hearth Pad? Pic Included

[ejwoodward]

So I decided to redo my existing hearth in anticipation of my new Quad Fire 4300. On the existing wooden hearth pad, I am going to put down 2 layers of Durock which should meet Quad's vague hearth protection (r value) requirement. The problem that I have is the pad will only extend 6 inches in front of the stove....not enough. I am going to tear out several rows of hardwood flooring to meet the 16 inch requirement. Because of a nearby doorway, i cannot raise the floor in front of the "pad" above the existing grade. As such, I will only be able to put down Hardi Backer Board topped with mortar and 1 inch of stone. My stove dealer told me that r value is only an issue directly under the stove and only ember protection is needed out front. Does anyone have any experiences with this? Thanks

 

[begreen]

Lay down some Durock NextGen cement board if you are concerned. It has a higher R value than hardibacker. Will 1" stone clear under the door? If not, you could do a nice 3/8" slate or tile border.

 

[ejwoodward]

Any thoughts on whether or not the stove dealers comment about only needing ember protection out in front of the stove carries any water?

 

[KaptJaq]

Any thoughts on whether or not the stove dealers comment about only needing ember protection out in front of the stove carries any water?

That depends on the stove. I know with my insert there is a large window and the window starts about 6 inches above the hearth. When the secondary burn tubes light off the hearth in front of the stove can get to 150 degrees. That is why the manufacturer requires an R factor of 1.5 for 16 inches in front of the unit. I have seen other stoves that the documentation has the R factor drop off with increased height above the hearth. Somebody that is familiar with the 4300 will have to comment on what they have experienced.

KaptJaq

 

[ejwoodward]

I have also heard that the R value requirement does not play a role beyond the hearth pad when the hearth is raised above the floor grade; however, I have not seen any documentation to support this.

 

[Danno77]

As far as I know if the stove requires an R-Value for the hearth (pad), then it's the entire thing, not just some of it.

edit: but beyond the pad you are free to do whatever you want. Many opt to have more ember protection out front, because it's not all that unlikely to have stuff pop out some distance with the right firewood.

 

[Backwoods Savage]

Any thoughts on whether or not the stove dealers comment about only needing ember protection out in front of the stove carries any water?

Most likely he is right. However, it would be nice to have this in print and the stove manual should have this information. The reason for having it in print is for passing code and also should the worst happen, you will have your protection because you went with the manufacturer's requirements.