Hearth pad construction question

[barrettdp]

Hello and thanks in advance!

We are in the process of installing a VC defiant stove. The manual states that the hearth pad must be built completely from non-combustible materials. So after research here I decided to use the steel studs from home depot double upped and layed on flat to create a 1"+ air space to the subfloor. Then covered with 2 pieces of wonderboard and tile. The manual does not state anywhere that the air space needs to be open so that fresh air can move in and out. It does however state that this design is needed on the wall shields. So this is how we made ours. It did not dawn on me that this flow of air may be necessary under the hearth pad as well, again because the manual makes no mention of it. So my question is does my hearth need some holes under it to allow air flow? BTW we do plan on installing the factory sheet metal bottom and rear heat shields.

 

[Dakotas Dad]

Does your stove need a certain "r" value in the hearth? If not, then "ember protection" is all you need, and you have attained that. Most stoves put far less heat downwards then to the sides/front/back..

 

[barrettdp]

Does your stove need a certain "r" value in the hearth? If not, then "ember protection" is all you need, and you have attained that. Most stoves put far less heat downwards then to the sides/front/back..

No R or K value is mentioned per manual. However it does state that the hearth flooring must be completely non-combustible, and even states that wood framing would not qualify (obviously).

 

[firefighterjake]

My own take would be if no R value is mentioned for the hearth your plans should suffice . . . generally you'll find more heat is transmitted to the side, back and front of a stove than from the base.