Since asbestos was included as an additive when siding was manufactured for many decades, the odds are good that original shingle siding on holder homes may contain asbestos.
“May” is an important distinction, though. Never assume that asbestos is present unless it has been tested.
Asbestos wasn’t always added to cement siding and there’s no way to tell from a visual test or physical inspection on site if siding really does have asbestos in it.
Identifying Asbestos Siding
The only way to be sure if your siding has asbestos in it is to collect a sample and send it to an accredited testing lab.
Contractors and inspectors (or anyone identifying asbestos siding) can’t tell from just an on-site inspection whether or not your siding really has asbestos in it. They can make educated guesses — and may often be proven right — but the only way to be sure is to have a sample of your siding tested for asbestos.
The age of an home or the siding on it isn’t definitive proof that siding or any other material in in contains asbestos. Some companies included asbestos in all their home building products while others didn’t.
Tips for Collecting a Sample for Asbestos Testing
Several companies sell expensive asbestos testing kits but these are largely unnecessary, as they’re simply a few plastic bags and a dust mask.
Asbestos siding is one of the safest materials to work with due to its installation outdoors so collecting a sample is much easier and safer than collecting a sample of sheetrock or insulation.
Try to find areas where siding is cracked and damaged, as you’ll often be able to remove a piece for asbestos testing with very little effort.
Each lab will have different procedures and protocols but you essentially seal the sample in a bag, label it properly, and send it off to a lab.
Never cut or saw siding that you think may have asbestos in it, even when trying to collect a sample for testing.
If you must break an intact shingle for a sample when identifying asbestos siding, carefully apply pressure to a corner of a shingle in an inconspicuous spot until a piece breaks off.