A. Bill Feist, an expert on finishes in Middleton, Wisc., responds: Since asbestos-cement shingles do not expand and contract with humidity changes like wood siding does, they hold paint very well. If the asbestos-cement siding is already painted and the paint is in good condition, clean the siding and then use a high-quality acrylic latex paint. Dirty siding will require a good cleaning (a detergent wash followed by power washing and thorough drying) to remove chalk and dirt.
Priming may not be necessary if the old paint is in good condition (free from peeling, cracking, flaking, etc.). However, if the old paint is glossy, or there are bare spots, it may be best to prime first. Use the primer recommended by the manufacturer of whichever acrylic latex paint you use. Be sure to apply two coats of topcoat paint, since...
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