Craze Cracking, Say What?

When an home inspector at Pacific Coast Inspections, Inc. walks a composition shingle roof; they’re on the lookout for ‘indicators’ which will help them explain the condition of the roof to the homebuyer.cracked composition shingles sacramento inspector

First, a little technical talk… Composition shingles are manufactured with an asphalt layer and covered with colored granules to protect the asphalt from the sun’s damaging ultraviolet radiation (UV rays).

The main shingle element connected with the asphalt layer and how well it stands up to weather over the long term are volatiles.


Volatiles are chemical compounds added to the asphalt to help keep shingles waterproof and flexible. Over the years, volatiles are slowly lost to evaporation. Loss of volatiles causes asphalt to dry and craze-crack. See photo.

Another cause of surface cracking is the shrinkage of the asphalt in the shingle’s coating; that can occur between two permanently affixed points – the shingle fastener and the self-sealant material on the shingles tabs.

Rest assured that the shingles are still shedding water at this stage of surface cracks. Eventually, the shingles will deteriorate as they approach the end of their service life and the roof will have to be replaced.

Pacific Coast Inspections, Inc. will always recommend a roof review by a licensed roofing contractor, when shingle cracks are observed.

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