We get asked this question a lot-what exactly does hail do to asphalt shingles and why does they need to be replaced after a big storm?

 

Hail comes in all shapes, sizes, and densities. If you're unfamiliar with how it forms, here's a cute science video: https://www.youtube.com/watch?v=1701cmpi69g. Basically, condensation in the air freezes and continues to grow as an ice ball. When it finally gets heavier than the uplift can hold, it falls to the ground.

Spring and Summer are typically the best conditions for making large hail. Stones range from little pea-sized hail up to massive softball and grapefruit sizes. Of course, the larger the hail, the faster it falls and lands with greater force!

 

How does this affect the roof?

 

Shingles are pretty basic. There's a base mat, the asphalt body, and granules on top for UV protection, aesthetics, traction, and impact protection (of varying degrees).

The job of the shingles is to keep water out of the house and to protect the decking (typically made of wood). When hail strikes the shingles, the impacts cause bruising and possibly breaking the backing of the shingle. Over time, water will find its way through the shingle and into your house.

In Colorado, snow sits on your roof, melts during the day, freezes again at night over and over. The snow melt gets into the hail hits and, when it freezes, it expands those hits. Also, as the snow slides down your roof, it takes those granules with it leaving your shingles even more compromised!

Once water gets into your house, this will be highly problematic - damaged property, damaged wood like rafters and such, damage to your insulation, mold, etc. This can be incredibly costly which is why it's easier and cheaper for insurance companies to pay to replace your roof if there's enough damage vs. paying thousands of dollars for interior damage.

Now, this is focusing on asphalt shingles as the vast majority of homes in CO have this type of roof, but hail can certainly negatively affect other roofing products, too. Asphalt is the cheapest option and roofing companies like installing it because they know it'll get damaged easily (read: The dirty secret about the roofing industry. Here's what they don't want you to know...and, yes, hail proof shingles DO exist.)

You can't often see hail damage from the ground so make sure you get a roofing professional you trust to do an inspection.