Need opinion on my hearth design

[Shortstuff]

I have already spent quite a lot of time searching both here on the forums and online to determine if my below design would be acceptable for a safe hearth underneath my new QF Castile pellet stove. I've gone so far as to contact the QF factory tech department to find out if any specific k-value or R-value is recommended for the hearth beneath my stove and they have no such specifications on record.

My owners manual says: Hearth Pad Requirements (UL and ULC) - Use a non-combustible floor protector, extending beneath appliance and to the front, sides and rear as indicated.

I've asked my local building inspector and he says that it must meet the requirements set forth in the owners manual. I asked my dealer and he said that as long as it's a non-combustible material, like tile underneath, that's all I need.

I am installing this stove myself and safety is MOST important to me. I know that a 1/2" layer of Micore placed between the two layers of Durock would probably satisfy the requirements needed, but it's not readily available around here. So, my question is if what I have drawn below would be enough to ensure a safe installation or should I add a 1/2" layer of Micore in there?

Thank you in advance: Steve

 

[jtp10181]

If you ever plan on putting a wood stove here, that would be a thing to keep in mind. If it will always be a pellet stove as far as you are concerned then what you drew is fine. Even one layer or Duroc would be fine. The bottom and shell of the pellet units doesn't get very hot. It could be running for hours and you could probably hold your hand on the bottom forever. The heat mostly comes out the convection tubes, which its out and up away from the stove.

 

[Corie]

While your floor protection should not sit on top of a rug, if the Owner's Manual states that the stove only needs non-combustible floor protection than that's all you need. There is no R-value because the floor protection is only to prevent ember burns and hot ash from contacting the surround floor. This means you can construct your hearth however you want, as long as the top layer is noncombustible. It could be as simple as a thick sheet of tempered glass (looks wonderful on wood floors) or as complicated as what you want to build. Your hearth is extreme overkill, but there is nothing wrong with that. Safety first and if that's what makes you feel better and feel comfortable having the stove in your home, then go for it.

 

[jtp10181]

Yes, they are, but they are are in no way "non-combustible"

A rug is NOT adequate hearth protection for a pellet stove, unless it is made out of concrete.

 

[JPapiPE]

I made my last hearth as prescribed by the sellers of the Jotul I bought. It was very simple. Start with 3/4 Plywood (CDX is the cheapest) over that place a sheet of 1/4" asbestos millboard (sold at some lumber yards and very cheap) or 1 layer of 1/2 durock and over that place a piece of 16 gauge sheet metal, and lastly I finished it with 1/2" slate tiles and then framed the whole perimeter with 1/2" pine and stained and urethaned it. Of coarse you must grout the tiles. I think gray grout is best because it doesn't show the ash/coals spillage as readily as a white grout would. Plus make sure you add a latex additive to your grout as changes in temperature will crack ordinary grout. When you get done with the grouting you will have a mess of grout smears to clean up. Use a big sponge and a bucket of warm water and when you tire of this give the grout another 24 hours , then take a cloth damped with lemon oil and it will remove all the grout smears still on the tile. Hearths never really get too hot and I could always place my hand on any portion of the hearth and it was only warm and never hot.

Just my method, Joe

 

[Shortstuff]

Thanks everyone for your input. I want to be more safe than sorry. Being retired I'll be home 99% of the time to tend to my stove and keep her in the best running condition, but as with anyone else I want to have peace of mind when I do leave the house.

Thanks very much!

Steve