Ceramic Fireblankets as a heat shield to reduce clearance

rtrev37

New Member
Aug 28, 2018
83
New York City
Hello everyone,

Recently I have run across a wood stove that I really liked (Drolet HT2000) and replace my older stove(Fisher Grandpa Bear). However, the new wood stove requires a 53" clearance from the stove top to ceiling according to its manual - Which I do not have. Due to the raised floor (which can not be removed) and the brick hearth already in place, I have 47 inches of clearance left (short by 6 inches).

I am aware that a 28 gauge of sheet metal suspended with a 1 inch spacer will reduce the required clearance but since the stove is located in the foyer of my home, I think it will not look so aesthetically appealing and kind of ugly. Going for a smaller stove or other stove models is not a real option either, since I have not seen any other model that I liked over the HT2000 with its abundance good reviews.

QUESTION: Can a ceramic fire blanket be attached to the ceiling to act as a heat shield and reduce my clearance? since the ceramic blanket is white, it will blend in much better with my ceiling over a suspended sheet of metal which can not be painted.

It seems this topic of ceiling clearance is nearly non existing or not as popular and is the reason I wanted to post it- in case others had the same issues and possibly someone to point to something about ceramic fire blankets that I was not aware of.

Lastly, If ceramic fire blankets can withstand constant and continuous direct fire without heat going thru it, why is it never mentioned or used as a heat shield to reduce clearance on a combustible wall or ceiling for a wood stove? is there something I am not aware of?

Thank you all
 

begreen

Mooderator
Staff member
Nov 18, 2005
81,306
South Puget Sound, WA
No, the ceramic blanket would not be a proper shield. You'll need to do a non-combustible shield on 1" standoffs. It can be painted white so that it does not stand out. Use high temp paint.
 

rtrev37

New Member
Aug 28, 2018
83
New York City
No, the ceramic blanket would not be a proper shield. You'll need to do a non-combustible shield on 1" standoffs. It can be painted white so that it does not stand out. Use high temp paint.
The same high temp paint used on the wood stove? Now that is an idea. Thanks for the idea.

However, a wood stove ceramic fire blanket is non combustible, and will not require an air space to cool anything off as piece of metal requires. I'm still wondering why a ceramic fire blanket can not be used? not sure if the metal sheet with a one inch spacer was an old method no manufacturer bothered to change over time because of high cost in retesting or maybe the ceramic fire blanket has improved over time that no manufacturer bothered to add it to their manual due to cost of changing the manual and again retesting. I mean so many possibilities yet have not found the "why not?" answer. It seems that a fire blanket is superior to a 28 gauge sheet metal although placing a ceramic blanket on a ceiling does have its challenges, like how to keep it from falling apart over time.

This post is helping me to think more on this and hope others can find it useful...thanks for the high temp paint idea if they have it in white...lol
 

begreen

Mooderator
Staff member
Nov 18, 2005
81,306
South Puget Sound, WA
Stove paint or high temp BBQ or header paint are all fine. Most hardware stores carry this. The 1" ventilated air space is tested and has a high r-value. The insulation blanket is not tested and most likely a lower r-value. Also, over time the blanket would probably be a dust and soot magnet. The heat shield can simply by wiped clean.
 

rtrev37

New Member
Aug 28, 2018
83
New York City
Stove paint or high temp BBQ or header paint are all fine. Most hardware stores carry this. The 1" ventilated air space is tested and has a high r-value. The insulation blanket is not tested and most likely a lower r-value. Also, over time the blanket would probably be a dust and soot magnet. The heat shield can simply by wiped clean.
Stove paint or high temp BBQ or header paint are all fine. Most hardware stores carry this. The 1" ventilated air space is tested and has a high r-value. The insulation blanket is not tested and most likely a lower r-value. Also, over time the blanket would probably be a dust and soot magnet. The heat shield can simply by wiped clean.
If it became a soot magnet, something seriously wrong with my stove but a dust magnet is a good possibility to keep in mind and cleaning the metal heat shield is an easier job over cloth type material. something to consider.

Does anyone have pictures of a suspended sheet metal acting as a heat shield over a wood stove? that would be a rare pic but making it look good is the catch....

And how to attach a ceramic fire blanket to a ceiling is becoming a challenge in itself. Any screws used must be totally protected from heat due to it being a good conductor of heat and transferring that heat to the combustible wood beam or dry wall it is attached to. I might be seeing the light.
 
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rtrev37

New Member
Aug 28, 2018
83
New York City
Ok here is another reason why a ceramic fire blanket may not work - it may not allow a good airflow above the wood stove as heat rises. Not too sure how heat and airflow reacts with a ceramic fire blanket but it seems that it will restrict the flow of air due to its rough and thick surface. A 28 gauge sheet metal is thin and smooth enough to allow air to flow across and behind its surface without restricting airflow. it does not seem to be so with a ceramic fire blanket.

Lets keep adding to the pros and cons to this if any ….now I want to ask what is a good way to install a metal heat shield above a wood stove while make it look good? lol lol
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
20,707
central pa
Ok here is another reason why a ceramic fire blanket may not work - it may not allow a good airflow above the wood stove as heat rises. Not too sure how heat and airflow reacts with a ceramic fire blanket but it seems that it will restrict the flow of air due to its rough and thick surface. A 28 gauge sheet metal is thin and smooth enough to allow air to flow across and behind its surface without restricting airflow. it does not seem to be so with a ceramic fire blanket.

Lets keep adding to the pros and cons to this if any ….now I want to ask what is a good way to install a metal heat shield above a wood stove while make it look good? lol lol
To make it look good and be sturdy you need to bend a lip on the edge. In the back I usually bend it down and leave that an inch away from the wall. In the front I bend up 3/4" and use 1 3/4" spacers so you still have your 1"gap.
 

rtrev37

New Member
Aug 28, 2018
83
New York City
To make it look good and be sturdy you need to bend a lip on the edge. In the back I usually bend it down and leave that an inch away from the wall. In the front I bend up 3/4" and use 1 3/4" spacers so you still have your 1"gap.
Hum, what's the purpose of bending the tips? I'm trying to imagine how that will look.

I was thinking of getting a spacer longer than 1" to increase the air flow without compromising the aesthetics. I think the max is 3"

Question: once installing the Heat shield in the ceiling, will I even need a double wall pipe? the back is a full masonry brick wall with no combustibles behind it. and thought using two 45's and one straight pipe to connect the two. I've seen that design on manuals but have not actually seen anyone do it....seems like many simply use a 90 then go horizontal into the wall while increasing the horizontal passage. i',m trying to minimize the length of that horizontal with the two 45's and a straight unless that will increase my wall to stove distance - which I do not want to do.

Sorry for all the questions. My first time replacing an old stove that was already there when I bought my house.
 

begreen

Mooderator
Staff member
Nov 18, 2005
81,306
South Puget Sound, WA
For a shield I prefer a hemmed edge where the outer 1/2" is folded flat to the back. That works well with 1" spacers and looks tidy.

If the single wall has more than 18" from any combustible then it's fine. Using 45's to soften the 90º turn is a good idea where possible.
 

rtrev37

New Member
Aug 28, 2018
83
New York City
For a shield I prefer a hemmed edge where the outer 1/2" is folded flat to the back. That works well with 1" spacers and looks tidy.

If the single wall has more than 18" from any combustible then it's fine. Using 45's to soften the 90º turn is a good idea where possible.
Is that for aesthetic purposes begreen?
 

begreen

Mooderator
Staff member
Nov 18, 2005
81,306
South Puget Sound, WA
Is that for aesthetic purposes begreen?
Yes, though it will also stiffen the sheet a bit. Not that this is a big deal up on the ceiling. This is a 1 minute job on a sheetmetal brake.
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
20,707
central pa
Hum, what's the purpose of bending the tips? I'm trying to imagine how that will look.

I was thinking of getting a spacer longer than 1" to increase the air flow without compromising the aesthetics. I think the max is 3"

Question: once installing the Heat shield in the ceiling, will I even need a double wall pipe? the back is a full masonry brick wall with no combustibles behind it. and thought using two 45's and one straight pipe to connect the two. I've seen that design on manuals but have not actually seen anyone do it....seems like many simply use a 90 then go horizontal into the wall while increasing the horizontal passage. i',m trying to minimize the length of that horizontal with the two 45's and a straight unless that will increase my wall to stove distance - which I do not want to do.

Sorry for all the questions. My first time replacing an old stove that was already there when I bought my house.
I like to bend the edge to stiffen it. That means fewer hangers and less heat transfer. Personally I like the look of the thicker edge as well but that is a personal choice
 

brenndatomu

Minister of Fire
Aug 21, 2013
4,737
NE Ohio

rtrev37

New Member
Aug 28, 2018
83
New York City
Could use a sheet of copper too...if you didn't want to paint tin...could even hammer it, if you like that look...or might be easier to just use metal ceiling tiles (just make sure they are actually metal!) there are a ton of options out there!
https://www.americantinceilings.com/pattern3-nu/?msclkid=3e48229e9217195b86507e6dbf91a2ab&utm_source=bing&utm_medium=cpc&utm_campaign=(Corey) ATC Shopping&utm_term=4576854590500147&utm_content=Ceilings
hum. I just saw some of the pics of the tiles on the ceiling that looked really good. Yet these tiles are conductors of heat. If they get hot enough, the combustible behind them could ignite if I placed them directly on the drywall. How do I get around that without the 1" air flow behind them to cool them off? unless they sell them in different sizes where I can use them 1 " off the ceiling, but then the next questions is, are they at least 28 gauge of metal?

I just looked at the website, the copper is made of .010 inches of copper which is a 30 gauge. A ceiling heat shield should be 24 gauge minimum of sheet metal according to the manual, which is .0239" thick. ( 2.5 x the thickness of a copper tin)

They might sell them thicker but I will need to ask so your suggestion is not in vain. its still an idea.

Thanks
 
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begreen

Mooderator
Staff member
Nov 18, 2005
81,306
South Puget Sound, WA
It doesn't need to be made of sheet metal, but it does need to be non-combustible. The shield could be made of cement board which can be tiled.
 
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brenndatomu

Minister of Fire
Aug 21, 2013
4,737
NE Ohio
How do I get around that without the 1" air flow behind them to cool them off?
You don't...still need to space them out
 
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Simonkenton

Minister of Fire
Feb 27, 2014
1,541
Marshall NC
FrivjjQl.jpg

Use hammered copper, like I did. Easy to work with, looks good.
 
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rtrev37

New Member
Aug 28, 2018
83
New York City
It doesn't need to be made of sheet metal, but it does need to be non-combustible. The shield could be made of cement board which can be tiled.
Lots of good options. Going to try the diamond treaded aluminum sheet of .025" from Home Depot but will need a wider sheet. They have 36"x36". I think I need a 60" by 66" so I might just place two side by side or buy one large sheet and cut it to desired Length. and see how it looks. It's still in a trial run to see how that will look. if It like it and it looks good, I will post it but if not, I will go on the next suggestion.
 

rtrev37

New Member
Aug 28, 2018
83
New York City
View attachment 244637

Use hammered copper, like I did. Easy to work with, looks good.
I just saw hammered copper is also of 24 gauge. This is another great option because it's also light weight. Going to attached the link simply to keep it for future reference.

http://www.colorcopper.com/categories/Hammered-Copper-Sheets/?msclkid=a91e74250798122e3fcd28d110f905a9&utm_source=bing&utm_medium=cpc&utm_campaign=Copper Sheets - CC&utm_term=hammered copper sheets&utm_content=Copper Sheets - Hammered
 

Simonkenton

Minister of Fire
Feb 27, 2014
1,541
Marshall NC
Well, that is some good looking copper. I don't know what gauge mine is. I hammered it myself, it was smooth when I bought it.
I laid it down on a big flat log and went at it with a ball peen hammer.
 
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rtrev37

New Member
Aug 28, 2018
83
New York City
It doesn't need to be made of sheet metal, but it does need to be non-combustible. The shield could be made of cement board which can be tiled.
I just got an email response from the Ht2000manufacturer on my question as to acceptable ceiling heat shield material- They stayed that Aluminum can not be used but rather a 24 gauge steel with either ceramic or copper 1” spacers.

I also emailed the manufacturer of the aluminum sheets and provided them with the purpose of the aluminum sheet and they, as well, replied that aluminum sheet would not be acceptable due to it being too light weight and potential sagging above a high heat source.

So it seems aluminum and copper may work for the wall but not so much for the ceiling. But then again, how much does a 24 gauge 5x5 steel weigh??
 

rtrev37

New Member
Aug 28, 2018
83
New York City
It doesn't need to be made of sheet metal, but it does need to be non-combustible. The shield could be made of cement board which can be tiled.
I agree with you. As long as it’s noncombustible, what’s with all the regs and specific type of material by the manufacturer? So now I need a steel ceiling? I would say that’s ridiculous but they may have a good purpose for it. I don’t know. However, a ceiling would be subject to much more heat then a wall and the nature of gravity seem to play a big role.

On another site, I was reading that cement boards are not acceptable due to containing paper as a shell which ignited and cracks over time with a stove top heat. It failed inspection.

Humm
 
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brenndatomu

Minister of Fire
Aug 21, 2013
4,737
NE Ohio
On another sight, I was reading that cement boards are not acceptable due to containing paper as a shell which ignited and cracks over time with a stove top heat. It failed inspection.
Micore board...
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
20,707
central pa
I agree with you. As long as it’s noncombustible, what’s with all the regs and specific type of material by the manufacturer? So now I need a steel ceiling? I would say that’s ridiculous but they may have a good purpose for it. I don’t know. However, a ceiling would be subject to much more heat then a wall and the nature of gravity seem to play a big role.

On another site, I was reading that cement boards are not acceptable due to containing paper as a shell which ignited and cracks over time with a stove top heat. It failed inspection.

Humm
Cement board doesn't contain paper it is fine. But if SBI says you need to use steel that is what you need to use. And 24 gauge steel is light I would say 10 lbs for a 5x5 at most. We usually use 22 just because it is a little stiffer.
 

begreen

Mooderator
Staff member
Nov 18, 2005
81,306
South Puget Sound, WA
On another site, I was reading that cement boards are not acceptable due to containing paper as a shell which ignited and cracks over time with a stove top heat. It failed inspection.
What cement board has a paper shell? Sounds more like gypsum board.