My current masonry fireplace has a 16" x 60" hearth which is flush with the carpet and the cement in the fireplace that my current insert sits on. I've ordered a C450 Jotul which requires an 18" hearth as measured from the glass and the glass sits about 2.5" out from the front of the fireplace. This means I need about a 22" deep hearth and it needs to have an R factor of 2.9.
Since my current hearth is flush with the floor, I thought I'd build a new hearth measuring about 22" x 62" that I can simply place over the existing hearth. This way I can simply lay the new hearth over the existing hearth and won't have to tear up the old one or cut carpeting because the edges of the new hearth will simply rest on the carpeting.
My choices seem to be these: 1) since the stove and the hearth need to rest on the same level, I can build my hearth all the way from the back of the concrete insert floor area and extend it out 22 inches or, 2) I can build the hearth flush with the wall and out 22" and this means I need to elevate the back of the stove to be even with the hearth elevation, which is no problem. But if I do this, how do I then keep the EDGE of the wooden frame of the hearth which sits under the lip of the insert from being too close to high temperatures?
I've heard people say to use metal studs with insulation stuffed in-between the studs to achieve high R-values but at the studs themselves the only R-value you have is the Durrock or other material which sits on top of the studs and since I need an R of 2.9, how do I get R=2.9 AT each stud? That is, between the studs you have a high R value because you've placed insulation in between them but AT each stud you only have a metal beam so how does one achieve a given R-value AT each stud and what does code say about reduced R-value AT the studs?
Any suggestions?
Since my current hearth is flush with the floor, I thought I'd build a new hearth measuring about 22" x 62" that I can simply place over the existing hearth. This way I can simply lay the new hearth over the existing hearth and won't have to tear up the old one or cut carpeting because the edges of the new hearth will simply rest on the carpeting.
My choices seem to be these: 1) since the stove and the hearth need to rest on the same level, I can build my hearth all the way from the back of the concrete insert floor area and extend it out 22 inches or, 2) I can build the hearth flush with the wall and out 22" and this means I need to elevate the back of the stove to be even with the hearth elevation, which is no problem. But if I do this, how do I then keep the EDGE of the wooden frame of the hearth which sits under the lip of the insert from being too close to high temperatures?
I've heard people say to use metal studs with insulation stuffed in-between the studs to achieve high R-values but at the studs themselves the only R-value you have is the Durrock or other material which sits on top of the studs and since I need an R of 2.9, how do I get R=2.9 AT each stud? That is, between the studs you have a high R value because you've placed insulation in between them but AT each stud you only have a metal beam so how does one achieve a given R-value AT each stud and what does code say about reduced R-value AT the studs?
Any suggestions?
![[Hearth.com] Building hearth for WB insert](/talk/data/attachments/2/2849-32e5a6d5008610f4eb9254ca3fb63a74.jpg?hash=5h_EcCoY2I)
![[Hearth.com] Building hearth for WB insert](/talk/data/attachments/2/2844-b02be5c29d7ae26bccddc2e8947587bd.jpg?hash=5h_EcCoY2I)
![[Hearth.com] Building hearth for WB insert](/talk/data/attachments/2/2873-0ede0902bee1f4a55bf8819eb91e1982.jpg?hash=jwG-F3ddvF)
![[Hearth.com] Building hearth for WB insert](/talk/data/attachments/2/2887-a0d793d3e58bd4fdec1b4c62357ef6b7.jpg?hash=DcXts6CEJI)
![[Hearth.com] Building hearth for WB insert](/talk/data/attachments/2/2890-e00f91fc27871523b37563e0da546675.jpg?hash=Anho-wA5OR)
