Unlike some home problems, such as water damage or pest infestations, asbestos can be very difficult to spot. Asbestos is a mineral in the form of microscopic fibers and was previously used in building materials for its bonding and fireproofing abilities. Insulation, roof shingles, ceiling tiles, floor tiles, pipe wrappings, soundproofing materials, and textured paint features like popcorn ceilings are common sources of asbestos, particularly in homes built before 1980.

Age is perhaps the biggest indicator of asbestos, as legislation passed in the 1970s labeled asbestos as dangerous and regulated its use in building materials. Signs of age in the form of wear and tear or material degradation are also indicators that asbestos fibers may be leaking into the air, but ultimately, it’s difficult to detect with the naked eye. If you have reason to suspect asbestos in your home, it’s best to hire a certified asbestos inspector.

Through air sampling devices and surface swabs in key areas of concern.

Knob and tube wiring is an older type of electrical wiring that's no longer used and generally not considered safe. However, some homes still have it, or may have a knob and tube wiring system that was incorrectly modified or rigged to work with a modern electrical system. Knob and tube wiring may contain asbestos insulation, but the only way to know is to have the material professionally tested.

Do not panic if you are exposed to asbestos. The illnesses associated with asbestos exposure are rare. If you are concerned about exposure, talk to your doctor, especially if you are having any respiratory symptoms, such as coughing or difficulty breathing. They may recommend imaging to get a view of the insides of your organs and determine if scarring or growths are present.