Ask an Expert: Do Ice Dams Harm Shingles?

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Ask An Expert is a question-and-answer column designed to address common questions related to forensic investigation and property damage. Each month we’ll feature one or two questions submitted by you – our readers and customers – and provide detailed, easy-to-understand answers. Email your questions to [email protected] or submit your questions here.

 

Are roof shingles damaged by ice damming or are they damaged by the water intrusion resulting from ice damming? If not, how does the water get in?

Adam Cabral, P.E.: Ice damming is a phenomenon in which water from melting snow or ice flows down the roof and refreezes along the colder eave, creating a dam. Subsequent meltwater pools on the roof behind this dam.  The pooling water backs under the shingles and leaks into the building.  Because ice dams, like snow or sleet accumulation, build up on the top side of the roof shingles, the roofing is rarely damaged by the accumulation of ice.  Ice damming can contribute to the debonding of shingle sealant strips, though this only occurs at shingles in contact with the accumulated ice dam, not higher up on the roof slope.  Often, the bond between the shingle sealant strips will return with warmer weather conditions.

 


About the Expert
Adam Cabral, P.E., joined Donan in 2013 as a forensic engineer based out of the firm’s Boston, Massachusetts office. He has eight years of engineering experience, and has completed approximately 450 forensic investigations. His area of expertise is structural building damage assessment, and his project capabilities include structural impact evaluations, construction defects, water intrusion, flood studies, and roof inspections, among others. View Adam Cabral’s full professional profile here.

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