# Fireplace wood -> gas conversion and code impact



## GregD (Jul 29, 2019)

Hello, I was hoping the folks on this forum could help me understand the code around fireplaces - specifically with regards to hearth extensions and when a wood to gas conversion has taken place.

The specific code in question:
R1001.9 Hearth and hearth extension
R1001.10 Hearth extension dimensions

I have two fireplaces that are essentially stacked on top of each other. One in my living room and one in my master bedroom. I'm looking to redo my hearth extensions, as they're in dire need of a makeover (think really crummy 1970's tile).

My interpretation of R1001.9 is that if the hearth extension is built over combustible material, such as the plywood subfloor on my second floor, the hearth extension technically cannot come in contact with the floor. It somehow needs to float or be cantilevered over the subfloor. Is that interpretation correct? 

Note that for me the 8" clearance exception would not apply. I'm in around 6.5".

Although my fireplaces are no longer wood burning and use gas logs (open burner, not a self-contained insert), R1001.9/10 still applies, right? I thought I heard somewhere "once wood burning, always a wood burning fireplace". Is that statement correct?

If the above statement is correct, are there any exceptions which would exempt me from these rather rigorous hearth extension guidelines? If I went and replaced the gas burners with a fully manufactured gas insert which essentially "plugs up" the old masonry firebox - would I then no longer be subject to R1001 and be bumped over to R1004 rules? I would then just use the manufacturer's spec for hearth extension requirements.

Thanks, any insights would be greatly appreciated.


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## cda (Jul 29, 2019)

Welcome

Not into fireplaces

I think mine is natural gas, but when I moved in I used wood 

My floor is concrete but have carpet about 18 inches away.

If you still have the install paperwork for the gas insert, or can find online

See if the manufacture either requires or recommends a hearth distance.

Seems like once you go gas, the wood should not matter.


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## cda (Jul 29, 2019)

*R1004.2 Hearth extensions.*
Hearth extensions of approved factory-built fireplaces shall be installed in accordance with the listing of the fireplace. The hearth extension shall be readily distinguishable from the surrounding floor area. Listed and labeled hearth extensions shall comply with UL 1618.


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## cda (Jul 29, 2019)

Looks like gas falls under chapter 24



*G2427.5 (503.5) Masonry, metal and factory-built chimneys.*
Masonry, metal and factory-built chimneys shall comply with Sections G2427.5.1 through G2427.5.9.

*G2427.5.1 (503.5.1) Factory-built chimneys.*
Factory-built chimneys shall be installed in accordance with the manufacturer’s instructions. Factory-built chimneys used to vent appliances that operate at a positive vent pressure shall be listed for such application.

*G2427.5.2 (503.5.3) Masonry chimneys.*
Masonry chimneys shall be built and installed in accordance with NFPA 211 and shall be lined with approved clay flue lining, a listed chimney lining system or other approved material that will resist corrosion, erosion, softening or cracking from vent gases at temperatures up to 1,800°F (982°C).

Exception: Masonry chimney flues serving listedgas appliances with draft hoods, Category I appliances and other gas appliances listed for use with Type B vents shall be permitted to be lined with a chimney lining system specifically listed for use only with such appliances. The liner shall be installed in accordance with the liner manufacturer’s instructions. A permanent identifying label shall be attached at the point where the connection is to be made to the liner. The label shall read: “This chimney liner is for appliances that burn gas only. Do not connect to solid or liquid fuel-burning appliances or incinerators.”

Read through it


Looks like starts around section 2427


https://codes.iccsafe.org/content/IRC2015/chapter-24-fuel-gas


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## al_ha (May 19, 2022)

GregD said:


> Hello, I was hoping the folks on this forum could help me understand the code around fireplaces - specifically with regards to hearth extensions and when a wood to gas conversion has taken place.
> 
> The specific code in question:
> R1001.9 Hearth and hearth extension
> ...



Did you find a definite answer to this question?
I am in the same boat; with a gas log fire place, which looks like is a conversion from a wood burning fireplace, and I would like to remove the hearth.


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## ICE (May 19, 2022)

The OP did not return for an answer.


A gas log in a fireplace does not negate the hearth code. 

As a side note: Make sure that the flue damper has the hardware that prevents the damper from being fully closed.


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## Msradell (May 20, 2022)

ICE said:


> As a side note: Make sure that the flue damper has the hardware that prevents the damper from being fully closed.


That's 1 of the problems with gas logs in a conventional fireplace, the requirement for a device to keep the flu from being fully closed! It causes a huge energy loss most of the time.


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## Beniah Naylor (Nov 16, 2022)

Thread resurrection:

What inspections do you all require for a conversion of a wood burning fireplace to a gas insert in an existing house? It seems like it would need two inspections, one before the box is installed to verify the new gas line and the flue that was installed are correct, and then a final inspection after the box is installed to ensure that everything is connected properly and close out the permit.

How do you guys handle it?


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