Asbestos cement siding is known for its extreme durability and can remain functional for decades when maintained properly. Because it was manufactured with asbestos fibers to add strength to the Portland cement matrix, it is highly resistant to fire, rot, and termites.

While the material itself has a long life expectancy, its safety status is the more critical factor for homeowners. We recommend keeping the following safety and regulatory points in mind:

• Category II Nonfriable Classification: Under U.S. federal regulations, asbestos siding is classified as a Category II nonfriable material. This means it does not easily crumble when dry, but it can become hazardous and release toxic fibers if it is broken, sanded, or cut.
• Visual Similarities: You cannot determine the age or composition of siding by sight alone. Legacy asbestos-cement and modern fiber-cement siding look nearly identical. Laboratory testing is the only way to confirm if your siding contains asbestos.
• Professional Testing: Only trained professionals should collect samples for testing. Homeowner-led sampling is discouraged by the EPA because improper handling can release fibers that would otherwise remain safely contained.
• Regulation Thresholds: If a renovation involves disturbing more than 160 square feet of asbestos-containing siding, federal NESHAP regulations apply, requiring specific professional removal and disposal procedures.

If your older siding is damaged or you are planning a renovation, let us help you get your project started with professional guidance. Please consult a licensed contractor for definitive advice; verify licensure with the Colorado Department of Regulatory Agencies (DORA). Project outcomes and timelines may vary based on site conditions, permitting, material availability, and unforeseen issues. Estimates are preliminary and subject to change after site inspection and a full scope review.

• Is Cement Fiber Siding Asbestos? The Complete Safety Guide