Mantel clearances?

[Coldnga]

We are considering a princess PE 29 insert for our downstairs fireplace, the mantle is 21 inches deep and 44 inches from the bottom of the mantle to the hearth. My question is how do I insulate the mantle from the insert because maximum depth is listed as 12 inches by blaze King?

 

[begreen]

That's a deep mantel and a good question for their support staff. They may accept a heat shield on standoffs, hung on the underside of the mantel.

 

[Coldnga]

That's a deep mantel and a good question for their support staff. They may accept a heat shield on standoffs, hung on the underside of the mantel.

Would Rockwool insulation filling the space between the angled heat, shield, and the bottom of the mantle suffice, and what type of sealant could be used to prevent the heat from entering the space?

 

[begreen]

No, an air gap of an inch is all that is needed and that's quite effective. Here's an example:

 

[Coldnga]

Considering the depth of our mantle would a 1 inch standoff be adequate, and is it not required to be sealed around the perimeter? I would think that heat would still enter the space if it were not sealed at the perimeter?

 

[Coldnga]

I failed to mention that the large fireplace opening extends to within approximately 4 inches of the depth of the mantle but the insert would be recessed in the fireplace fire brick flush with the back of the 21 inch deep mantle!

 

[begreen]

Considering the depth of our mantle would a 1 inch standoff be adequate, and is it not required to be sealed around the perimeter? I would think that heat would still enter the space if it were not sealed at the perimeter?

Yes, it would cover the area but it is definitely not sealed. It's the ability of air to circulate behind the plate that keeps it cool.

 

[begreen]

This sounds like a very large fireplace. A picture of the fireplace with dimensions would be helpful.

 

[Coldnga]

This sounds like a very large fireplace. A picture of the fireplace with dimensions would be helpful.

I apologize for the lighting, but here are two photos!

 

[Coldnga]

This sounds like a very large fireplace. A picture of the fireplace with dimensions would be helpful.

I’m sorry I didn’t realize you wanted dimensions. I’ll try to get them tomorrow.

 

[begreen]

Oy, I'm not sure why they did that. It's an awful design but I see the challenge now.

 

[Coldnga]

TERRACE LEVEL
Firebox inset dimensions
Width: 49” at front, 39” at rear
Depth: 25.5” at bottom, 15.5” at top
inward taper starts at 10.5” height
Height: 32” at front, 41.5” at rear
Stone fascia inset dimensions
Width: 66” at front and rear
Depth: 18” uniformly to firebox
Height: 49.5” hearth to mantel
Mantel dimensions
Width: 66” at front and rear
75” total width set in stone
Depth: 21” uniformly
Height: 6” uniformly




 

[begreen]

This was made mostly for show and not for go. Why trap a fire in a cave with a combustible shelf over it? In the least, the mantle should be made of a non-combustible material. That will simplify things. I don't know if this company does custom.

MagraHearth | Non-Combustible Fireplace Mantels

MagraHearth's non-combustible products include mantels, fireplace surrounds, hearth boards, and stove pads.

magrahearth.com

Whatever the solution, it will probably need sign offs from the stove manufacturer and inspecting authority.

 

[fao1989]

How about replacing the wood mantel with granite or some other stone? Would look nice and no longer combustible, right? Bet you could get an off-cut of granite from a local yard and get it cut to size, and beveled or square cut on the leading edge for less than $250.

 

[fao1989]

Or alternately, just remove the mantel entirely? Looks like it lifts right off.

 

[Coldnga]

It is inset in the stonework of the surround, but could be removed.

 

[Coldnga]

Could a propane fueled set of gas logs provide enough heat without removing this mantle? I would need to purchase the propane tank and the gas logs and installation, is this a possibility and does anyone know the approximate cost? I have noticed that some of the gas logs have fairly high output, this would be only used on occasion, not full-time..

 

[spudman99]

I have a PI 29. Attached is a picture of a heat deflector shield I crafted to divert some of the direct heat from the insert way from my mantle. Said mantle is only 8" wide however, yours looks wider. I used rockwool to seal the gaps between the brick and the shrouds. My mantle does get warm, but my IR thermometer shows nothing higher than 90 or so degrees. No visible marks on the wood so I feel ok.

If you are looking at just occasional use, then a gas log may be better and cheaper. Kinda expensive to install a BK insert with liner to just use it sporadically. Much easier to fire up a gas log. I am assuming you are seeking ambiance rather than a secondary heat source.

Depends on your age, situation and desires -- a woodstove may grow in appeal as you enjoy the warmth and then use it more often. If so, carefully consider your time commitment to gather, stack and shuttle wood into the stove. This is a labor of love and is not for everyone. If you do decide on a stove.... secure some wood NOW and let it season. I cannot stress how important dry wood is to a safe and successful experience in a Blaze King (or any other stove for that matter).

 

[begreen]

Could a propane fueled set of gas logs provide enough heat without removing this mantle? I would need to purchase the propane tank and the gas logs and installation, is this a possibility and does anyone know the approximate cost? I have noticed that some of the gas logs have fairly high output, this would be only used on occasion, not full-time..

Any installation needs to be safe for full time operation, even if that is not the plan. One never knows what need will present itself in the future. There could be a bitter cold snap with an extended power outage, or a future owner of the house that wants to use it all the time.

 

[spudman99]

I cant find the edit link to add the pic from yesterdays post. Here it is for reference

 

[begreen]

A mantel shield was suggested or replacement with a non-combustible mantel.

 

[Coldnga]

A mantel shield was suggested or replacement with a non-combustible mantel.
View attachment 344181 View attachment 344183

The idea in illustration # 1 looks intriguing, would the heat dissipate beyond the edge of the mantel? I also wondered about the amount of heat generated from a gas log set up, would it be in the neighborhood of a wood insert or significantly less?