Galvanized sheet metal for fire barrier

I’m trying to decide how I feel about this somebody installed galvanized corrugated metal around the fireplaces probably to act as the non-combustible material however it’s so thin I could probably cut it with a really good pair of scissors. The metal is not combustible however there’s nothing there to stop heat transfer through it.


As a side note which I’m going to research later tonight this fireplace has the world’s tallest chimney.

First place… what is shown in your photo IS NOT a “fireplace”…
You can’t ‘research’ until you have the correct terms for what you are dealing with.

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Thank you for that great insight Jeff. You’re insight is always truly helpful.

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I’m not saying it’s OK, but here is something to consider. From the picture it looks like typical corrugated sheet metal sold at the big-box stores. That stuff is probably in the area of 26 gauge or so.
Ducts penetrating the fire separation in an attached garage must be 26 gauge.

What is the distance from the stove to the metal and what does the manufacture say for distance to combustibles? What is behind the metal?

I would use all of this information to make an educated recommendation or decision on if it goes in the report because you will likely not find a concrete answer on this scenario.

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I wonder if may have been installed more as for heat reflection as opposed to an actual fire barrier, or possibly both.


that looks like a fire waiting to happen from here…


Interesting after doing a quick illustration look up for wood stoves, corner placement varies based on manufactures’ installation guidelines. I saw anywhere from back corners placed min 6.5 inches from non-combustable (sheet metal) walls to 13 to 18 to 23 inches for combustable walls. I guess the underlying is the what the manufacturer states for installation.
However, the OP’s pic appears that it’s closer than any minimum that I saw in a brief search.


From here, too, Jim.

The metal would need plenty of air space behind it not to transfer the heat from the wood stove to something combustible behind the metal.


From @sbridges2 article seems to cover it well unless you have manufacturer installation instructions.

No! National Fire Protection Association (NFPA) codes permit reduced clearances to combustible walls if adequate protection is provided. Sheetrock, sheet metal, masonry veneer and other thin or non-insulating materials placed directly against walls give little protection. These materials conduct heat very well; they will be almost as hot on their back sides as they are on their exposed sides.

Reduced clearances are acceptable for the following:

  • an engineered protection system approved by the inspecting authority having jurisdiction
  • products and materials listed for protection purposes
  • a non-combustible protector mounted an inch or more away from a combustible wall to allow free circulation of air behind it

The reduction is specified by NFPA and most codes. For example, when required clearance with no protection is 36 inches, a 3 1/2-inch-thick masonry wall with ventilated air space used as a wall protector, reduces clearance by maximum of 66 percent, to 12 inches from the combustible wall.


“Directly against the wall” is key wording. A minimum 1" air gap is often used using certain materials. In this case, does the corrugated sheet metal, as installed, meet that 1" minimum air gap?


It doesn’t look like it, and it also looks like the stove is only about 1’’ inch away from the sheet metal, Like Jim said, it looks like a fire waiting to happen. :thinking:

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We would have to know the clearance requirements by the manufacturer. Otherwise, we use the 36" rule which can be reduced to 12" with air gap and 24 gauge metal (or other approved) I doubt that metal is 24 gauge based on the OP description. Too many unknowns overall.



I agree about the stove being too close, but it’s hard to tell if the air gap is sufficient. It does appear that there is one, and the material is not flat, attached directly to the wall. It’s a great question and good learning experience for all of us. :wink:

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I saw that illustration too Brian. But had to dig deeper into a corner mount installation.

Right, what are the panel screws attached too? Combustible material? Furring strips for air gap? Not enough information but now we know what to look for :smile:

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Also, might need more updated information

“This document is taken from the University of Delaware Cooperative Extension, Newark, Delaware. Publication Date: October 1991.”

Here is a pic from the manual of a common wood stove sold at my local big-box store. These are out-of-the-box clearances. They don’t give reduced clearance dimensions, stating to contact your local safety department for those.


One of the wood stoves that I installed could be even closer than 12" because it had a heat shield attached to the stove. Like this:

wood stove

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Based upon the label on the unit 9.5" clearance in corner. There’s only 6’ish inches on this one in the corner