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Chimney & Fireplaces/prefab fireplace installed in brick chimney


I have a martin industries prefab built in fireplace (SA36)which was installed in 1992. I have the manual from when installed and it shows UL instructions to install. The fireplace is installed in an exterior wall and sets on a footer/block/concrete slab which extends into the living room by 16 inches. From the inside, it is installed in the 2x4 frame wall and the outside is surrounded by a brick chimney with a base which is built around the fireplace. Immediately above the fireplace, the chimney is built with 4 brick sides and extends up 2 stories. The fireplace chimney is an E series triple wall pipe which extends up through the chimney.  The brick chase is built the same as shown in the UL listing, but the listing appears to refer more to the traditional wood chase which is insulated and contains a firestop at each floor.  The difference here is that that brick chimney has 4 sides which is brick 1" away from the outside sheathing as required, but there are no firestops in the chimney since the triple wall chimney is completely surrounded by brick and is outside the house. Have you ever seen this type of chimney construction on a simple prefab fireplace ?  The UL instructions say that for an installation on an external wall, you must build an insulated chase on the outside of the building, but they do not designate the material as wood or brick.  The chimney is not insulated.  The only downside that I can see to this is if the brick were not sealed and leaked, it may rust out the fireplace. I am going to open up the chimney and check the box for rust.  Is there anything wrong with installing in brick ?  We are selling the house and I do not particularly want to remove a brick chimney extending 27 feet high which is built as part of the house and replace with a wood chase chimney.

Hello Dave, not sure what you have there, "insulated" means like attic insulation, you outer wood wall should be insulated and maybe enough, did you have a permit pulled for this chimney? I would be interested in if that chimney chase is fire stopped and supported corectly, I would have a local Certified Chimney Sweep, (there you can look up by zip code to find one near you) take a first hand look at what you have, they should be able to help.
Hope this helps

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James Ball


I am a chimney sweep with over 22 years of experience, CSIA certified and member of the NCSG, I can answer questions about smoky fire places, wood stoves, and heating units (boiler and furnace chimneys) do you need a relining? A cap? And much more


over 22 years

Chimney Safety Institute of America, National Chimney Sweep Guild

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