Asbestos Cement (Mineral Fiber) Siding

ASBESTOS CEMENT (MINERAL FIBER) SIDING
Asbestos cement siding is essentially a light concrete panel reinforced with asbestos fibers. It was a common siding material in the mid 1900s.


Asbestos cement siding typically comes in large shingles. Sometimes the surface is grooved or mildly corrugated. They are usually painted white or pastel colors. This siding is almost always installed horizontally, with consecutively higher rows overlapping the row below. Be careful when identifying this material. There are other materials very similar in appearance to the asbestos cement shingle.

Asbestos cement is a good siding material that, in many areas, has unfairly developed a bad reputation because of its asbestos content. There is no evidence that there is any health issue associated with this siding while on a building. Asbestos fibers can be a health issue if they are friable. This means that fibers are free to float around in the air and may be inhaled by people.
With asbestos cement siding, the asbestos is not free or friable. People sanding or cutting asbestos cement shingles should consider this, but other than during construction activities, this shouldn’t be an issue.


The siding is extremely durable and its only arguable weakness is that because it is brittle, it is susceptible to mechanical damage. However, most other sidings are also susceptible to mechanical damage, and one has to hit an asbestos cement shingle pretty hard to break it
Another advantage to the asbestos cement siding is that it is tolerant of moisture, and while the substrate may be vulnerable if it is installed too close to grade, the asbestos cement siding itself will not deteriorate even if buried in the ground.


Another benefit of the asbestos cement siding is its non-combustibility and, to a lesser extent, its fire resistance. As most people are aware, asbestos is used as insulation against heat in many applications. However, since asbestos cement siding is typically secured with steel nails, there is a limit to the fire resistance.


Matching replacement pieces for damaged shingles may be hard to find.
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