Asbestos in Chimneys, Furnaces, and Wood Stoves
Asbestos is found in homes and other buildings constructed before 1980. Because it is cheap, durable, and readily available, asbestos was commonly used in numerous home construction materials. If you live in an older home, you should be aware of the risks of asbestos exposure including the risk of developing mesothelioma.
Asbestos is commonly used in home heating due to its resistance to fire and extreme heat. Chimney flues, furnaces, and wood-burning stoves were all commonly made with asbestos. Originally used to make homes safer, materials in your home heating equipment could actually pose a health risk. If disturbed, fibers of asbestos may become airborne where they can be inhaled. If you think you may have asbestos, a certified professional can inspect and abate it.
Transite Asbestos in Chimneys
Many chimney flues, exhaust pipes from fireplaces, were lined with a material called transite. This was a brand of asbestos-containing cement material created by Johns Manville. Transite was originally a brand name. However, the term became a common word for any similar material. Originally, transite was made with cement mixed with 10 to 50 percent asbestos. Asbestos in transite was phased out by 1980.Homes built before 1980 are likely to contain transite with asbestos, most often in chimney flues. The material was used to line chimney flues in commercial buildings and residential homes. The purpose of the flue lining is to resist fire and keep heat from escaping. Chimney flues were not the only flues that used transite with asbestos, however. Any venting flue, even ones connected to water heaters, furnaces, and other appliances, may contain asbestos, especially in older homes.
Asbestos is no longer used in chimney and other venting flues, however it may still be present in older homes. Renovation or construction work done on the chimney and flue can expose asbestos, sending fibers into the air. Even when there is no renovation work, asbestos in older flues can harm residents. The lining material of the flue may deteriorate over time, causing blockages that in turn cause exhaust gases, along with asbestos fibers, to vent back into the home.
Furnaces and Asbestos Materials
Furnaces are also a potential source of asbestos in older heating system. It is not just the venting flue that may contain this material. Several types of material containing asbestos were used to insulate furnaces and protect surrounding walls. These materials include millboard, cement sheet, transite materials, asbestos paper, and asbestos tape.
Furnace gaskets also contained asbestos prior to 1980. Gaskets are rings that connect two materials to prevent leaks. Furnace gaskets used asbestos to prevent heat leaking out. The doors of furnaces were often lined with asbestos materials. Vents and ducts leading to and from furnaces may also have been insulated with asbestos.
Asbestos materials can be dangerous today because heat from the furnace can cause asbestos to become friable over time. Friable means the asbestos can easily crumble, causing fibers to become airborne. Since friable asbestos is particularly dangerous, it should be removed by a trained asbestos abatement professional.
Another asbestos source in heating systems of older homes is the wood-burning stove. In addition to ducts and the flue used to vent gases, asbestos may be found in components of the stove itself. It may also be found in insulating material around it. Also, a wood stove may have millboard, cement sheet, or asbestos paper and tape for insulating and fireproofing.
Older stoves may also have asbestos in door gaskets. Wood-burning stoves with cook-top surfaces may contain asbestos in their pads and trivets. The heat of the stove can cause insulating asbestos to become friable. Therefore, asbestos-containing wood stoves should be inspected and abated by a trained asbestos professional.
Identifying Asbestos in Heating Systems
For the lay person, identifying asbestos is problematic and potentially dangerous. Determining whether or not you have asbestos materials in your chimney flue, furnace, or wood stove, is a task best left to trained professionals. Every state has its own licensing and training requirements for asbestos professionals, so check for a local professional.
Finding asbestos in your heating systems does not mean your family is in imminent danger. Well-contained asbestos that has not become friable poses no real risk. However, if you have a professional inspect your home and he finds friable asbestos, you will need have it abated.
Abatement does not necessarily mean removal. Whether it is most practical to remove the asbestos depends on the asbestos type of asbestos and condition. Your professional can determine if removal is the best option. The alternative is asbestos containment. If containment is the route you take, be sure to have it regularly inspected for damage or deterioration.
Asbestos can cause a lot of worry, especially if it is in and around the elements that heat your home and vent gases. With professionals inspection and abatement asbestos materials should not pose a significant health hazard. If you are unsure if your heating components contain asbestos, have them checked by a licensed professional. This is particularly important if you plan renovations or repairs.Having the inspection done first is crucial, and could prevent your family being exposed to harmful asbestos fibers.