Steel wall questions

[DaveNY49]

Did a search on this topic and didn’t see much. So here are my questions. I installed a steel wall behind my stove. It’s black roofing steel and it has a 1 inch air gap between the drywall and the steel. For some reason I can’t find ANY topic. (Here or online like Reddit or fb woodstove groups). I see many who have steel walls behind their stoves but no one giving opinion on how hot they get or how hot they shouldn’t get. I had my Huntsman stove 20 inches away from the steel and when I had my stove putting out max heat (which was 650 off the top and 550 off the sides) the steel directly across from the stove woukd get as hot as 195. And never showed any issues. I’m installing a new stove. A Fisher Teddy bear that has the heat shield on back. I’d like to get it as close to the steel as I can. So I’m looking for any opinions. I’m pretty sure I think I know what I can get away with already but figured I’d bring this question here.

Just want to add I homestead and do NOT have insurance or codes I have to worry about. But I DO want to be safe. I was thinking of adding another section of steel over the existing steel wall and leaving an inch air gap. That would be two sheets of steel with 2 inches of air between them. I’ve tested the steel and it can get well close to 300 degrees with no issue. Please drop me your ideas.

 

[stoveliker]

@coaly knows Fisher stoves.

One remark is that codes apply regardless of insurance or rural areas. Your county has a code for stove installations, whether you choose to follow them or not.
There is a liability concern when (safety) code is knowingly and wilfully ignored.
But it's your life. I hope no one else lives with you and is dependent on the choices you make about their safety.

 

[DaveNY49]

@coaly knows Fisher stoves.

One remark is that codes apply regardless of insurance or rural areas. Your county has a code for stove installations, whether you choose to follow them or not.
There is a liability concern when (safety) code is knowingly and wilfully ignored.
But it's your life. I hope no one else lives with you and is dependent on the choices you make about their safety.

Do you have an opinions on how close a stove can be from steel? At what degree does the steel combust? I know you are REALLY code minded and focused. Which I don’t mind. I’m not against them all together either. But if you were able to step outside that box and think outside the box for a moment could you give me a scenario where the steel combusts? I’m interested in learning. At what temp does steel combust? I know what temp it glows at…and I’m so far from approaching those it’s nuts.

If you can friend, put the code book aside and do some measuring and go ahead and answer my main questions….does drywall with an inch air gap, steel, another air inch air gap and then more steel make those wooden studs behind the drywall safer or unsafer? I’d love your help so I can plan. Also, I may remove the drywall and studs all together and use steel studs, ceramic insulation, and then a steel wall.

Let me know man…I know you are a smart guy. Thanks

 

[stoveliker]

Steel never combusts. It might melt. But your stove would disintegrate before that.
(Steel powder can combust, but plate won't.)

The air gaps will make it safer. Do have an inch or two at the bottom and the gap open at the top so you can have convection behind the steel

Generally stoves are tested to be safe at some clearance. If nothing is in the manual, one is deemed safe when it is 36".from combustibles.
Sometimes it is safe to go down to 1/3 of that distance by having a vented wall like you are describing (1" before the wall,.gaps at bottom and top).

I don't think anyone can say what distance is safe beyond those remarks because no one has measured that. Moreover it depends on how much heat you radiate from the stove, which depends on draft, load, air setting (stove leakage), etc

 

[begreen]

The clearance is determined to the nearest combustible. That is the surface behind the steel if it's drywall and studs. If the steel shield wall is supported 1" off of the wall and has a 1" gap at the bottom and top so that air freely convects behind it, then the stove back can be 12" from the combustible wall behind the shield.

 

[EatenByLimestone]

You’re asking people to encourage you to put yourself, and possibly others in danger by skirting building codes.

Thinking outside the box, that’s a bad idea.

 

[DaveNY49]

Steel never combusts. It might melt. But your stove would disintegrate before that.
(Steel powder can combust, but plate won't.)

The air gaps will make it safer. Do have an inch or two at the bottom and the gap open at the top so you can have convection behind the steel

Generally stoves are tested to be safe at some clearance. If nothing is in the manual, one is deemed safe when it is 36".from combustibles.
Sometimes it is safe to go down to 1/3 of that distance by having a vented wall like you are describing (1" before the wall,.gaps at bottom and top).

I don't think anyone can say what distance is safe beyond those remarks because no one has measured that. Moreover it depends on how much heat you radiate from the stove, which depends on draft, load, air setting (stove leakage), etc

Good input man. Thanks. Although a different stove, this stove company actually does give a detailed list about heat shields and as you can see it reduces the clearance

 

[DaveNY49]

You’re asking people to encourage you to put yourself, and possibly others in danger by skirting building codes.

Thinking outside the box, that’s a bad idea.

Re read man. I’m asking calculated input. For people to do the math. My encouragement on rather I do it or not comes from me. Here is an example. A woodstove company that took the time o actually show how verious walls with one inch air gaps can change a stoves clearance.

 

[stoveliker]

Yes,.but my remark was that no one can say what.the numbers are for your stove if no one measured it.
What.is valid for other stoves has no bearing on yours.

Of course a vented wall shield won't make things worse

 

[begreen]

Re read man. I’m asking calculated input. For people to do the math. My encouragement on rather I do it or not comes from me. Here is an example. A woodstove company that took the time o actually show how verious walls with one inch air gaps can change a stoves clearance.

A manufacturer can pay for testing to be done and get the stove certified for lower clearances, but that is not the case here. In this situation, NFPA 211 code prevails.

 

[coaly]

The stoves you are referring to have nothing to do with the stove you are installing.

When stoves are tested, the shields used can reduce clearances. We don’t know if you have a Teddy Bear with factory shield and UL Label or not.

First you need to tell us if the UL Label is on the stove.

This will determine clearance to combustible. The Label gives backwall or corner installation clearances as well as pipe and chimney connector.

This is only if the factory heat shield is present.

If you need it closer, NFPA-211 is the tested source and national standard you must follow to be able to reduce clearance down to 12 inches minimum.

The Standard gives minimum metal thickness, and all details needed to construct your own ventilated heat shield.

https://fcpros.com/wp-content/uploads/2023/04/NFPA-211-2019-FR.280.10.pdf

Chapter 13.6 has the information you need. There is also a table there with alternate ways to reduce clearance, but the ventilated heat shield allows the most reduction of 66% down to 12 inches minimum. At that distance, stove pipe clearance becomes an issue as well. This is covered in the Standard.

I am not telling you to go by any building code, I am giving you the place to find the information where this has been tested and makes a safe installation. It is also the National Standard that becomes the minimum requirement where no building codes exist.

 

[begreen]

For more info:

Wood Stoves and Fireplaces - WOOD STOVE WALL CLEARANCES - PRIMER

Written by Ken Rajesky, Hearth Industry Expert. After the difficult decision of what stove to buy has been made, you’ll need to install the stove safely. However good the stove is, it’s still not safe unless installed to manufacturers specifications. First, review the owners guide that came...

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