Mantle shield

[clark77]

So in getting ready for putting in a new stove, I've got protect my mantle from the heat. Here's as picture of my current setup


So my cedar mantle is 2 1/4" thick by 7 3/8" deep and is 47 1/2" up from the hearth.
The jotul f55 that I'm going to get sits 30" tall so that only leaves me 17 1/2" of clearance. Jotuls manual says a min of 35" is needed between the top of the stove and the mantle.
Will I be good with only a mantle shield or are there other options that I need to look at?
How wide would you recommend making it (width of stove or entire mantle)?
I'm assuming that galvanized sheet metal is sufficient with the 1" air gap?
Thanks guys.

 

[Fsappo]

http://www.amazon.com/Chimney-54110-HomeSaver-Mantel-Shield/dp/B001D1DU3O

I've sold these premade ones in the past. Out of our retail locations, I think I would sell them for about $75. By the time most people bend, paint and mount the money spent was a good deal.

From what I understand, clearances to combustibles may be cut down by 1/3 if protected with sheet metal, unless specifically different in the specs provided by the appliance manufacturer

I also think they the shield needs to be 12" wider than the appliance it is protecting to each side, so you may need something 51" wide

 

[clark77]

i've seen those for sale and most are 47" wide. so if I need 51", then I would have to make something. I just want to clarify before I make or purchase something. and from what I can gather, the shields cut the distance by 50%. I just want to get everything set before the new stove.

 

[begreen]

The rules for a mantel shield seem a bit vague. I thought it was 8" past the stove top on each side but could be wrong. The docs do not say how wide to make it. They do say a 50% reduction in distance. This is what is in the HomeSaver installation guide:

The normal clearance for single-wall stovepipe to a combustible mantel is 18". The normal
clearance from an unlisted stove or insert to a combustible mantel is 36". The mantel shield
allows you to reduce clearances to 9" for stovepipe and 18" for a stove or insert per NFPA 211
standard and the International Residential Code.

 

[Fsappo]

ok, where did you see a sheetmetal shield reduces by 50%? owners manual? Yes, it does say it in the manual. It also says to refer to nfpa211. Gonna see how I remembered wrong

 

[Fsappo]

Ok, 211 says reduces by 1/3 for wall and 1/2 for ceiling, so if we call the mantle a ceiling than that 50% is consistent. With a 24ga minimum thickness

 

[begreen]

In 12.6.2.1(c) For a ventilated 24 ga metal shield I read a 66% reduction for walls and 50% for ceiling.

 

[Fsappo]

is that reduction or reduces it to .66 of original?

 

[Fsappo]

Never mind, NEVER MIND!
I cant read and answer phones at the same time

 

[begreen]

It's the maximum allowable reduction in clearance in %.

 

[clark77]

alright so am I good with what I plan on doing?

 

[begreen]

If your inspector and insurance company are happy, we're happy.

 

[clark77]

I just don't feel like doing things twice. If I can get it right the first time and not have to redo it that would be great.

 

[begreen]

Ask the inspector or at least the Jotul dealer first for verification on how far past the stove body the shield needs to extend. That seems to be the only open question. I thought it was 8" but fsappo thought 12". I looked at several inserts and note that their mantel shields typically are only the width of the insert. This is the Avalon shield.

 

[clark77]

I'm not going to need it for the insert but the jotul f55. I'll make it the width of the mantle then with the 1" air space

 

[clark77]

I wasn't able to get any sheet metal over the weekend so I ended up using a piece of aluminum that I had in the basement. After it was cut to shape, I cleaned it up and painted it with some high temp black spray paint. After it dried over night, I screwed it to the mantle with a 1" air gap in front and much larger in the back. The mantle is about an a half inch to the quarters of an inch away from the stone so the air will move through keeping the mantle cool.Here's the final product.

 

[Mag Craft]

What I like about the metal shields is not only do they shield the heat from a combustible but they seem to actually deflect more heat into the room. I made a couple of pieces from 20 gauge sheet metal and use them on the floor.

 

[Mag Craft]

Nice job by the way, it looks good and has enouph of a gap and some angle to it so the heat gets deflected into the room.

 

[begreen]

It should extend an inch beyond the front edge of the mantel. Hard to tell from the picture if it does this, but it doesn't look like it.

 

[clark77]

Good eye begreen, It's just shy of an inch.

 

[Mag Craft]

It will not take long to figure out once he starts burning if it is going to provide enouph shielding at the front of the mantle. Just put your hand on it and he will know real quick.

 

[clark77]

With my insert now running full bite, the shield is 105 degrees and the mantle under it is 80-85. Obviously the jotul is taller and will radiate more but the shield is working so far.

 

[Fsappo]

Remember, over years, as wood drys, the temp needed for it to burn lowers. I have seen a mantle turn to charcoal in the middle after 20 years of use. So slow and thru 2 homeowners. Present users assumed it was just smoke stain. May not have went up for another 20, but you do not need high heat to make a fire if the wood is dry and you give it enough time for....forgot the word, starts with a P...don't wanna google it to look like I have a great vocabulary.

 

[Beer Belly]

 

[clark77]

i ran into a fire inspector today in an adjacent town that i live. i asked him about the mantle and his thoughts on it and he didn't have an answer either. he said he never inspected a stove with a mantle shield but i should go by whatever the stove's manual states.
so in the manual it calls for 35" from the top of the stove to the bottom of the mantle. then it says " Mantle and Trim clearances may be reduced by 50% with use of shielding constructed in accordance of NFPA 211 specifications".
my stove dealer just called me before and my stove is in
so i'm going to go to my town tomorrow, get the permit and set up my inspection.
i picked up my tile for my hearth extension this morning and will finish that up tomorrow. its all starting to come together.