Siding that contains asbestos was incredibly popular in the 1950s and 1960s. The asbestos was used to strengthen the cement fiber shingle. To be honest, it worked. We often see siding that's in great shape and from this era. Unfortunately, any airborne asbestos fibers are harmful and homeowners should never repair or modify asbestos siding by themselves.
What is asbestos siding?
Asbestos siding is a cement fiber siding that is commonly identified by its uniform shape, nail heads visible at the bottom of each row, and large reveal sections (6-8"). Its a cement product that uses fibers to strengthen the cement. In this case, the fibers are asbestos. Cement fiber siding is still made today, just without asbestos as the strengthening fiber.
Is asbestos siding dangerous?
Asbestos siding should always be considered dangerous and never repaired, drilled, removed, or trimmed by anyone other than a trained hazardous materials professional. As with any thin cement product (tile, for example), cement can be brittle. An errant baseball, a rock thrown from a lawnmower, or even a car door opening against this siding can cause cracking and damage. Common modifications to the siding may be due to installing new windows, drilling/cutting holes for weather stations, bathroom fans, or dryer duct installations. Repair or modifications of any kind can lead to particulates becoming airborne and breathable. Even one fiber can be dangerous and lead to serious health consequences.
Should I replace my asbestos siding?
You should consider replacing your asbestos siding or covering (as many vinyl products will do), but need to contact a reputable siding contractor to understand the hazards and additional costs that may be required. Disposal fees, hazardous handling fees, etc. should all be understood prior to committing to a change. Each city and town may also have requirements for homeowners to follow regarding this and other known home material hazards. This siding is likely 60-80 years old and should be considered for replacement, anyway. Keeping the structure dry and as tight and energy efficient as possible should always be the goal.
How to I know if my home has asbestos siding?
Work with a professional inspector to determine what your siding is made of. Never cut into the siding to get a better look. This is exactly what you want to avoid.
Thanks for reading,
Matt and Matt
Square One Home Inspections, LLC