Asbestos Siding: Information And Management
Asbestos Siding
Asbestos siding was a very popular building material installed on millions of homes, particularly from the 1940s through the 1970s. Made from a mixture of Portland cement and asbestos fibers (usually chrysotile), it was valued for its incredible durability, fire resistance, and low maintenance. It was manufactured to resemble wood shingles, shakes, or slate and is often recognized by its brittle, cement-like feel and the fact that it is often nailed in place.
Homes with this type of siding are still common across the United States. A key point for homeowners to understand is that asbestos siding, when intact and in good condition, generally poses a very low health risk. The asbestos fibers are tightly bound within the cement matrix. The danger arises only if the siding is broken, drilled, sanded, or sawed, which can release the embedded fibers into the air.
Identifying and Managing Asbestos Siding
Identifying asbestos siding can be challenging, as it often looks like other cementitious siding products. Common indicators include a home's age (pre-1980), a pattern that mimics wood grain or slate, and a thickness and weight similar to cement. The most common sizes are 12"x24" shingles. The only way to confirm its presence is through professional testing by a qualified inspector.
The best management strategy for intact, undamaged asbestos siding is often to leave it in place. It can be painted over with an acrylic or elastomeric coating, which further encapsulates the material and modernizes the home's appearance. This approach is safe, cost-effective, and avoids the significant expense and hazard of removal. Regularly inspect the siding for cracks or damage and repair any issues promptly.
Considerations for Removal and Replacement
There are reasons a homeowner might consider removal, such as extensive damage, a desire for a different exterior aesthetic, or plans for significant renovations that will disturb the siding. Asbestos siding removal is a job strictly for licensed abatement professionals. They will follow rigorous safety protocols, including wetting the material, using hand tools to minimize breakage, and containing the work area to prevent contamination.
The process is labor-intensive and costly. After safe removal and proper disposal, new siding can be installed. If you are buying or selling a home with asbestos siding, its presence should be disclosed. It is not a defect if it is in good condition, but it is a material fact that future owners will need to manage responsibly.