Hail Damage vs Shingle Blistering: How to Tell the Difference

What Hail Damage Looks Like

Hail leaves a clear mechanical signature on asphalt shingles:

• Round dark spots roughly the size of the hail that fell
• Granules knocked off in a circular pattern
• The mat underneath feels soft when you press it — fractured fiberglass
• Random distribution across the roof, not clustered
• Matching damage on metal vents, gutters, and AC fins — the corroborating evidence adjusters look for

What Blistering Looks Like

Blistering is caused by moisture vapor trapped between shingle layers or under the shingle, then heated by sun. The vapor expands and pops the surface:

• Small bubbles on the shingle surface (intact blisters)
• Clean circular craters with sharp edges (popped blisters)
• The mat is still hard — no give when pressed
• Often clustered on south-facing or poorly ventilated slopes
• No matching damage on metal flashings, gutters, or vents

Why Adjusters Care

Adjusters are trained to distinguish the two because insurance covers one and not the other. A roof with widespread blistering and no real hail damage will be denied. A roof with genuine hail bruises, even a smaller number, gets paid. The corroborating evidence — damaged metal, bruised ridge cap, dings on AC fins — is what tips a borderline claim.

If You're Not Sure

Don't file a claim until a real roofer has been on the roof. If we find genuine hail damage, we file. If we find blistering, we'll tell you and explain whether it's a problem worth addressing. Either way, our free roof inspection will give you a clear answer before you call your insurer.

For more on the claim process, read will insurance pay for a new roof.