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Are Fireplace Inserts a Safe Option?

A fireplace insert is a manufactured fireplace that is designed to be installed into an already existing fireplace. These units can be solid fuel (wood) burning, pellet or gas appliances. The fireplace insert utilizes the existing firebox to place the insert into. And utilizes the existing venting system to have a liner installed to vent the insert. This is perhaps the simplest retrofit of a fireplace that is available on the market today. However, there are conflicts within industry standards and codes. Grand Flames believes that these conflicts must be addressed as an industry and should be considered by homeowners.

Most building code departments have adopted some version of the International Residence Code (IRC), and some also include the National Fire Protection Agency (NFPA) 211 Standards for Chimneys, Fireplaces, Vents and Solid Fuel-Burning Appliances. Grand Flames is unaware of any codes or standards in these publications that provide guidance in allowing a fireplace insert and its venting to be installed into an already existing fireplace and venting system. Underwriters Laboratory (UL) also plays an important role as well. Fireplaces, venting and their accessories are put through test to evaluate their safety. There are currently no listings that we are aware of that states that fireplace inserts, and their venting systems have been tested and approved for this application.

The real-world issues are just as important as the codes, standards and listings. We must look at the integrity of the existing system. Was the system installed correct originally? Is the system still functioning as it was originally intended? Does it still maintain it original integrity and safety features? Was the original fireplace and venting system intended, tested and listed to accept a fireplace insert and its venting system? Bottom line, is this a safe application? A lot of this relates to inspection of the existing system. Has the original system been thoroughly inspected and is it still operating under its intended specifications?

It is the belief of Grand Flames that in many instances these systems are simply put into place by installers and fired up without proper care, maintenance and evaluation. This is based on our observations, inspections and knowledge of how many fireplace companies install inserts. In many cases the existing flue was never swept or inadequately sweep. Was ALL creosote removed from the system? In many cases no. The primary hazard here is of a chimney fire. Creosote can ignite at 451 degrees and a chimney fire can reach 2000 degrees. This can have catastrophic consequences. Heat signatures are another issue. How is the heat from the insert transferred to the original firebox and then onto the surroundings such as the building structure and framing? It is not entirely known.

Mammoth Lakes, CA is a real-world example of the problems that fireplace inserts can cause. The results were a multitude of structure fires that were later determined to be the cause of the fireplace insert. The fire that was once in the original fireplace was now in the insert, which changed the location of the fire and reduced the clearance to combustibles in many cases. One residential complex in Mammoth Lakes, CA later required that these inserts be removed from the residences within the building. According to a Mammoth Lakes Fire Department report, “When all of the units were refitted with new appliances, and the wall opened up, 23 of 60 units show some sign of heat damage to combustibles because the proximity to combustible materials was too close.”

Grand Flames believes that there is too much uncertainty surrounding fireplace inserts currently. Codes, standards and testing conflict with manufacturers recommendations in some instances. We believe in safety above all else and it seems more safety conscious to install a new modern fireplace, rather than putting a modern fireplace insert into an existing fireplace and venting system that may have started to deteriorate. There are many options on the market today for all budgets, to safely replace outdated fireplace systems. There is NO safe fire within a building and as such we believe that safety should be put before all else to reduce the risk of catastrophic events.

Todd Osborne

Grand Flames

(970) 557-5151

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