# any pics of mantle heat shield????



## ncmallard78 (Oct 10, 2007)

i either need to move my mantle or install a heat shield.  current chimney is painted white.  im wondering if anyone has pics of a mantle heat shield installed.  im trying to get my arms around what they look like.  i have seen pics, but it looks like a black square tube.  or, is it a triangle shaped tube.  thanks again for your help.  im hell bent on getting a woodstove

fyi, the chimney sweep said that i cant burn wood in my fireplace as is, due to issues with cracks.  if i dont get a stove, i cant burn wood this winter....


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## Highbeam (Oct 10, 2007)

Here's a couple from the photo archive. Both on inserts of course. Personally I find them highly undesirable aesthetically, downright dangerous to your forehead when kneeling down to load.


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## Shawn (Oct 10, 2007)

Here is mine.  Don't use it as a mantle shield, but as a shield for the top facing which is just under 2" thick.  Not the best solution, but it worked out ok last year.  I really like the trim and would hate to take it off entirely.

Shawn


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## Harley (Oct 11, 2007)

ncmallard78 said:
			
		

> fyi, the chimney sweep said that i cant burn wood in my fireplace as is, due to issues with cracks.  if i dont get a stove, i cant burn wood this winter....



Where are the cracks the sweep mentioned?  I'd make sure those are addressed before you put a stove in (assuming an insert?)  If it's not good to go to use as a fireplace... it's not going to be good to go for a stove to be put in there.


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## jtp10181 (Oct 11, 2007)

Harley said:
			
		

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Unless you do a full insulated liner.


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## MrGriz (Oct 11, 2007)

jtp10181 said:
			
		

> Harley said:
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Unless the cracks are in the firebox.


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## Harley (Oct 11, 2007)

jtp10181 said:
			
		

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That's were I was going.


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## Gooserider (Oct 11, 2007)

Another shield option that I've heard about is to get a strip of metal and fasten it to the underside of the mantle on 1" spacers - some folks get the metal custom shaped to match the profile of the hearth.  This is a bit less of an eyesore, but is a much more "custom" type installation.

Gooserider


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## qwerty (Oct 11, 2007)

You'll find a lot of people who are positively aghast at the aesthetics of the mantel shield.  Personally, I don't mind them all that much.

Also, there may be other options you may want to consider.  I've had some suggestions from dealers regarding my mantel clearance issue.  One was to replace the wood mantel with one made of a non-combustible material, such as stone.  

Also, my wood mantel is mounted on top of bricks that stick from the rest of the masonry.  The support bricks are at either end of the mantel and are little columns four-high.   It was suggested that a metal heat shield could be fabricated and mounted under the support bricks, running between them.  This would make it a few inches below the mantel itself without having to have it protrude from the top of the surround.


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## ncmallard78 (Oct 11, 2007)

thanks for all your help.  my installer said that he would only do it if the liner was insulated.  

with regards to the mantle, i thought the shield attached to the bottom of the mantle.  this would be much better looking visually, and would most likely fly with my wife.  im thinking of fabing one myself, and painting it.  what is a good material for this?  of course, most important thing for me is safety!


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## qwerty (Oct 11, 2007)

Most seem to be made out of metal, which is strange to me because metal gets hot.  However, the most important thing they do is deflect the rising heat away from going directly to the combustible mantel.  If my understanding is correct, you wouldn't want the mantel shield to be touching the mantel itself; rather, it is necessary to leave some air space between the two.


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## Rhone (Oct 11, 2007)

I got a mantel shield, wasn't like those mentioned here was more like Goose says nothing but a piece of sheet metal bent to about a 45 degree angle, with 1" ceramic spacer washers to screw and hang below my current wood mantel.  It looked so bad I removed it and raised my current mantel then went about fixing the area between so it looked nice.  Was worth the extra work.  

I had a crack in the back of my original fireplace & face of my chimney.  I didn't notice, the Mason that removed my smokeshelf did.  He said the cause being my damper was put in tight against the bricks of my chimney.  Fine when there isn't a fire but you get a fire going the metal gets hot and it wants to expand.  Being tight against the chimney it had no place to expand so it made room and caused a crack going down the face and back.   He said since I have an inside chimney the back of it probably has 2x4 framing members against it and there's a chance that crack runs all the way through and may be against one and this scenario was the cause of a fire he read about.  After removing my smoke shelf he covered the whole back with at least an inch of cement that he said is good for high temperature then covered it with slag wool insulation (good to 2300F).  Anyway, my damper being enclosed and not having room to expand when it got hot was the cause of a crack in the face and back of my fireplace.


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## elkimmeg (Oct 11, 2007)

I willing to bet those heat shields are home saver heat shields that are actually tested and listed to be installed using ceramiic spacers per instructions of the listing it will effectively reduce the clearance to 18"  Sliding it behind the surround panel Is not an approved installation.  does not need the shield listing to what it has been tested. For all other applications are I think I have protection without any testing listing or supporting data.  I have the listing info here.  As an inspector I could never approve a usage not listed and tested

You know I can be wrong and there is a listing and testing approving the slide behind the surround application. I willing to be educated and learn


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## JMF1 (Oct 12, 2007)

My manual shows the mantle shield installed just above the stove/surround pcs. I fabbed one out of 14ga steel last year, bent it abot 40 degree angle and hated it. It's ugly and definately worth a trip to the ER for stitches in my opinion! I think the intention of it is to be down near the stove to direct heat out and away from the wall, not to be installed directly under the mantle itself. I refaced my whole fireplace with fieldstone from a local farm, it was fun and looks alot better than the old red brick anyway!


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## Gooserider (Oct 12, 2007)

My understanding of the physics behind the clearance requirements is that the primary concern on exposed combustibles like mantles and trim is RADIANT heating - the IR radiation coming off the stove, as opposed to any convection air.  If you look at the convection air off a stove, it usually isn't that terribly hot, so it is not a major problem, and could even cool a surface if that surface was hotter than the air.

Radiant heating on the other hand, follows an inverse square law (like all forms of radiated energy) and thus will be a function strictly of surface area and distance from the source.  By putting a clearance reduction surface in between the stove and the relevant area, you block the direct radiant energy.  Some of the energy may simply be reflected by the surface, (IR is LIGHT after all) and that which is absorbed will be re-radiated in ALL DIRECTIONS by the surface.  Since the surface has two sides (The edge can be considered negligible for this discussion) the effect is that half the energy that is absorbed will be re-radiated in the direction it came from, and the other half will be passed through.  Thus a protection wall gives an effective reduction in the radiant energy hitting the surface it protects of at least 50%.

The 1" spacers allow convection air to pass between the protective surface and the protected area giving additional cooling.  Since convectively heated air rises, the assumption is that side trim will be mostly cooled by the relatively cool air from the sides and floor of the room.  The trim also has a much smaller surface area, thus it is heated less to begin with, so the side trim clearance is lower.  The mantle it is assumed will be getting air that has been heated by the stove, and is also heated more because of it's greater surface area, so the clearance required is higher.

Gooserider


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