Ask the Inspector
Asbestos may be lurking in the air ducts of that old furnace
If it’s undamaged and not exposed to routine contact, there is no hazard. Otherwise, it’s best to call a contractor.
June 25, 2006
**Question: **A gas company serviceman said my furnace’s air ducts are made of asbestos. The house was built in the 1960s, and I’m afraid the old ducts may now be in violation of the building code. Am I required to have them replaced? Are they hazardous to the health of my family?
**Answer: **There are no laws or building codes that require homeowners remove asbestos-containing materials from their homes. As for the health risks to your family, that depends on the type, location and condition of the material.
From the mid-1950s through the early 1970s, sheet-metal air ducts for forced-air heating systems were commonly insulated with — or wholly constructed from — a cardboard-like material that contained asbestos fibers. In some cases, close examination is necessary to determine whether these old ducts are made of asbestos or merely insulated with it.
The material itself is not regarded as a significant health hazard if it is undamaged, securely attached and not exposed to routine contact. In such cases, the accepted advice is simply to leave it alone.
When metal ducts are wrapped with asbestos insulation, the asbestos-containing material is on the outer surfaces, not exposed to the air stream within the ducts, providing little or no opportunity for contamination of the circulating air. If the material is intact, it should be left as is. If it becomes loose, detached or physically damaged, patching or removal should be assigned to a licensed asbestos contractor.
Ducts that consist of asbestos material are not common, but they do exist. The interior surfaces of these ducts are covered with metal foil, preventing direct contact of the air stream with the asbestos material. However, if the ducts become punctured or torn, asbestos fibers can be released into the air. In that case, repair or removal by a licensed asbestos contractor would be advisable.