Will I make these clearances? And material and size for custom mantel heat shield

[KennyK]

I am installing a jotul F100 in front of my existing fireplace and venting it through the existing chimney with an insulated liner. I think I will make the clearances to my mantel on top and sides with some heat shields, but want some of the expert advice here. I believe that where the F100 gives clearances to "protected surfaces," that means as long as I have a heat shield separated with a 1 inch airspace it is a protected surface - my first question is is that correct?

I'm attaching a picture here of both the clearances from the F100 manual and a picture of my stove and distances to my mantel From my calculations, I am ok to the top large part of my mantel without protection - manual says 22 inches and I have 24.5. However, I have a trim at 12.5 inches from the stove - manual says 8" for protected top trim, so I believe if I start my heat shield under that I am ok, and then I have a second larger wood trim at 15.5" so I think if I continue that heat shield, I am ok with that too as manual gives 9" to protected mantel (again, I don't think I need to continue the heat shield to the top part of the mantel as that is ok distance for unprotected surface). For the sides, I have 10.5 to trim and 13.5 to second part of side trim - manual gives 7 to side trim (and 14 to unprotected), so I believe I can put a heat shield with one inch spacer on the side trim and extending to the second part of side trim and I'll be ok with that. Can people with more expertise here tell me if I'm correct on all of this? That is all part two of my questions! (Here is a link to the F100 manual if you want to see that: http://www.tallpinesfarm.com/web_ext/Owner's Manual/139678_R01_Manual F 100 NA_EPA.pdf)

Third question: in that manual it says that Wall-Mounted Protection in the U.S. must refer to NFPA 211, Standard for Chimneys, Fireplaces, Vents and Solid Fuel Burning Appliances, for acceptable materials, proper sizing and construction guidelines. If I want to make my own heat shields, can I use aluminum at .025 (which is one material I have easy access to), or 22 gauge steel (also have easy access to), or should I just suck it up and purchase one (or a three to do the top and sides) of these, which says it's up to NFPA 211: https://www.amazon.com/dp/B002VMH2R4/?tag=hearthamazon-20

Finally, with the heat shield, can I just go a bit past the dimensions of the stove, or should it cover the all of the mantel?

I am already pulled the permit for the install and have a person coming to do the liner in early January, but the heat shields are up to me.

Thanks for all your help!

 

[KennyK]

Just responding to my own post in hopes of getting some helpful input. My original post was kinda long, but the general gist is two things: 1) Am I correct in my understanding that when a jotul manual refers to a minimum distance to a "protected surface" that "protected surface" can be my wooden mantel as long as I have a proper heat shield with 1 inch airspace? If correct, do my clearances (in photos in original post) look good to you? 2) Does a homemade heat shield qualify NFPA 211 as long as it's made with 24 gauge (or lower) sheet metal, and if so does it matter if I use aluminum, steel or another metal? Also, I believe .025 thick sheet aluminum is 24 gauge - can anyone confirm?

Thanks!

 

[begreen]

The image posted shows the stove mostly out of the fireplace. Will the stove be top vented? If yes, in order to connect the stove it will need to be set further back into the fireplace. That would make shielding easier. A metal flange (shield) could be attached around the fireplace opening perimeter so that it projects an inch beyond the stove top. That should satisfy the closer clearance requirement. If the proposal is to top vent, then the side shields would need to project an inch further than the depth of the mantel sides and top shield will need to project an inch past the upper mantel trim. 22ga steel is a good choice. The .025 aluminum would work, but might be a bit flimsy for this application.

 

[jatoxico]

Probably know this but you inspector will what to see floor protection in front.

 

[KennyK]

Probably know this but you inspector will what to see floor protection in front.

Thanks jatoxico. Yes, I have an 18 inch hearth pad in front of my existing hearth, which is not in picture here. My only question about this is if I need something to lay over the seam where the built in marble hearth meets the 18 hearth pad extension. I was thinking of a strip of sheet metal so that there is no space a spark could fall in. Thoughts?

 

[jatoxico]

If it's a temporary hearth pad then that sounds OK to me. Last thing you want is a hidden ember smoldering away however unlikely.

 

[KennyK]

The image posted shows the stove mostly out of the fireplace. Will the stove be top vented? If yes, in order to connect the stove it will need to be set further back into the fireplace. That would make shielding easier. A metal flange (shield) could be attached around the fireplace opening perimeter so that it projects an inch beyond the stove top. That should satisfy the closer clearance requirement. If the proposal is to top vent, then the side shields would need to project an inch further than the depth of the mantel sides and top shield will need to project an inch past the upper mantel trim. 22ga steel is a good choice. The .025 aluminum would work, but might be a bit flimsy for this application.

Thanks Begreen! Always coming to the rescue of us newbies! I am going to rear vent (in the picture the stove has the top vent, but I will be switching that). Even with the rear vent, could I put the sheet metal coming off the fireplace opening and just extend it an inch more than the the depth of the side and top trim/mantel? I thought about that option as it would require less bending and cutting to form of a shield and I wouldn't have to mess with my nice 1890s mantel, but on the other hand, it might be harder to secure as the inside of my firebox is covered with a think iron plate on all sides. Also, when you write that a top shield would need to project an inch past the upper mantel trim, do you mean the highest part of the mantel? As the top of the stove to that part of the mantel is 24.5" and the unprotected clearances for this stove are 22", I thought I wouldn't need to come up to that, rather just an inch past the to the second part of the mantel trim which is 15.5" from the stove (or perhaps an inch and a half past that to make the 17" clearance to unprotected top trim). I agree that the 22 gauge steel feels a lot sturdier than the .025 aluminum, just seemed like the aluminum would be a lot easier to work with, but I did get a set of aviation snips, so once I figure out my approach to the shield, hopefully I will find those will go through the steel easily enough!

 

[begreen]

Upper mantel trim, not the upper mantel shelf which is already in compliance according to the supplied measurements.

 

[KennyK]

Upper mantel trim, not the upper mantel shelf which is already in compliance according to the supplied measurements.

Thanks! Knowing that I will be using the stove with the rear vent, what do you think about me putting the sheet metal shield coming off the fireplace opening (top and sides) angled up/out like this _/ and just extending it an inch more than the the depth of the side trim and upper mantel trim? Possible? Or better to just mount it to the mantel trim with spacers?

 

[begreen]

For simplicity's sake I'd probably mount it to the fireplace opening as in the first option. but the other way might work.