Luis Esteves of Adjusters International forwarded this photograph depicting a "zippering roof" during a windstorm:

Roof Zippering

Luis wrote:

. . . We have heard for years from the carrier’s that zippering is always a condition of bad installation and not wind uplift. Well, here is the smoking gun. I’m on my way to get this guy’s photo collection from that storm in Texas 5/24/14. Apparently he photographed all the neighbors’ roofs to prove his own claim, since he couldn’t go outside during the hail event.

Steve Thomas, just about the best roofing consultant that I know of, had this to say on the topic:

. . .Many times after the wind leaves these zippering impressions the shingles will reseal, however they reseal at a severely diminished value (approximately a 90% diminished uplift resistance value). The dirt and debris that will inevitably get embedded into the exposed mastic cannot be cleaned thoroughly enough to ever be reusable. Thus, the shingle must be replaced.

Positive Thought for a Labor Day Weekend by the King of the Labor Movement in America:

“Labor Day is devoted to no man, living or dead, to no sect, race or nation.”
    – Samuel Gompers

Work hard at having fun this weekend, my friends, while contemplating the value and fruits of every American working.