Central Ohio Joint Fire District
Fire Prevention Tips

Wood Fired Heating Appliances - Fireplaces and Wood Burning Stoves -

Each winter it seems we have more structure fires related to heating with wood. We are all trying to heat our homes in the most economical way, but, we need to keep in mind that homes built one hundred years or so ago were designed to be heated by wood. Today’s wood frame structures are not all designed that way.

As a rule, a home today might be built with a fireplace, but, the fireplace is not designed to heat the entire home. Modern, non – masonry chimneys are “triple wall” pipe (an inner pipe, a layer of insulation, an outer pipe) this is generally run in an open “chimney box” that is made of either plywood or OSB with siding on the outside. When the stack penetrates each floor, and the roof, there is an insulating flashing plate that is generally made of galvanized tin. This type of fireplace is designed to be more “ornamental” than to heat with. There generally is little or no masonry, only wood surrounding the stack. When we “stoke” this type of fireplace up to get it hot enough to try to heat the home, and to save on the natural gas or electric bill, it gets hotter in the stack than it was designed for, and the surrounding structure can heat up to the point that chemical changes (pyrolysis) occurs, creating a lower flash threshold. (Makes the wood that much more flammable, and can result in flammable gases). Homes with all masonry chimneys, that are properly maintained, are less likely to have problems as the masonry, by design, will take a higher heat load.

The other problem that we are seeing is the use of air tight wood burning stoves as a free standing, or whole house source of heat.

Keeping in mind that burning firewood produces a number of waste products, including creosote. Creosote is essentially the resins from the wood. When the wood burns, the resins are released as a gas / particulate and essentially “ride” the heat up and out of the chimney. When we strive to make the stove so efficient that it actively takes the heat from the stack, or allows the stove to “smolder” to get all of the heat out of a piece of wood that we can, we reduce the temperature of the gasses going up the stack and allow creosote and other particles to accumulate on the inside of the stack. Another problem we see is when a wood burning appliance is installed free standing in a room and there is a “cross pipe” going horizontally from the top of the stove to the thimble (chimney connection). Sometimes we see these cross pipes being several feet long. The problem is that, when the hot gasses are released from the top of the stove into the stove pipe and then have to travel horizontally for several feet to the wall thimble, they have cooled enough in the cross pipe to allow them to start going back to a solid form (creosote) and the buildup on the inside of the pipe is flammable, solid, creosote. At this point, the creosote will generally burn inside the pipe. The pipe is not designed for this sustained, direct heat and will start to fail, opening the stack to the home’s structural components.

You may have noticed of late that there are an increasing number of outdoor wood burning furnaces popping up in the area. When these are present and working properly, they are probably the best bet for whole house heating with wood. The fire itself is isolated from the home, so if there is a failure of the system, your house does not burn down.

Everyone needs to remember, or be made aware, that when homes were heated solely by wood, there was generally a fireplace in each room and the chimneys were masonry. Today’s home, as a rule, does not have a fireplace in every room, so, if someone wants to try to heat their entire home with one fireplace or wood burning stove, there is a good chance that they will find themselves overheating the stove / fireplace and endangering their home.

Proper cleaning and maintenance is a must. Simple chimney cleaning / brushing is not enough. Annual inspection of the wood burning appliance and chimney for creosote buildup and damage / wear is a must. A good comparison would be the exhaust system on your car. Eventually, it will need replaced due to wear / use. A chimney is the same thing. Constant heating and cooling from burning will cause expansion and contraction of joints in masonry as well as metal chimneys. If they are not maintained, they will fail.

If anyone has any questions about proper maintenance of your wood burning heating appliance, please contact the appliance manufacturer / installer, or call your local fire department.

Thanks,

Chief Porter

Open Burning -

The Ohio Revised Code and the Ohio EPA provide rules and regulations for open burning in Ohio. Open burning is prohibited between the hours of 6 AM and 6 PM during March, April, May, October and November.(ORC 1503.18 Kindled Fires)

The Ohio EPA Rules pertaining to open burning may be found at http://www.epa.state.oh.us/dapc/regs/3745-19/3745_19.html

ODNR Open Burning Laws brochure may be found at - ODNR Burn Laws

Furnace/Fireplace Safety -

Prior to the heating season, furnaces, fireplaces, wood burning stoves, etc should be serviced by a qualified technician.

Creosote can build up on the inside of a chimney, even if dry hardwoods are burned, and can result in a chimney fire that may become a structure fire. Preventitive maintenance is the key.

Change furnace filters on a regular basis.

Remember, natural gas and propane water heaters also produce combustion by products and should be serviced regularly.

Fire Prevention Materials and brochures are available at the fire station or by calling 740-625-5646 or emailing Central Ohio Joint Fire District. If you email us, please include your telephone number and mailing address.

LINKS -

Federal Emergency Managment Agency safety info for kids

National Fire Protection Association Fire Prevention for Kids

US Consumer Product Safety Commission

USDA/US Forestry Service Wildland Fire Safety

ODNR Open Burning Restrictions