What Does Hail Damage Look Like on a Roof?

Hail damage on an asphalt shingle is a bruise, which the engineering literature defines as an indentation with a fracture in the shingle mat that feels soft under a thumb. It is usually circular, it is usually darker than the shingle around it, and it is often easier to find by feel than by eye. Arrowhead Roofing has inspected hail on Tulsa roofs since 1987, and what separates damage from wear is not how bad it looks, it is whether the mat is broken.

Note: this is a general explanation of how hail damage is identified. It is not a statement about any particular policy. Arrowhead Roofing is not a licensed public adjuster and we do not negotiate insurance claims. What your policy covers is determined by your policy and your carrier.

Hail does not only land on shingles, and the rest of the house is often where the size and direction of the storm gets established.

The Short Answer

The industry splits hail effects into two categories, and only one of them is damage.

Functional damage is defined by Haag Engineering as a reduction in the water-shedding capability or the expected service life of the roofing material. On an asphalt shingle that means a puncture, a tear, or a fracture in the mat.

Cosmetic conditions are hail effects that do neither: a dent in a metal vent hood, minor granule scatter. Real, visible, and not the same thing.

That distinction is why a roof can look battered and not qualify, and why a roof can look almost untouched and be finished. Worth knowing, and worth knowing that these are engineering terms which do not automatically map onto the words in a policy.

What a Bruise Actually Is

Andy Anderson at Arrowhead describes what we are looking for on a slope:

We want to see something that’s distinctly different from the rest. It’s typically going to be black. We call them bruises, because the granules have been knocked off and have exposed the asphalt.

The engineering definition adds the part you cannot see. A bruise is an indentation with a fracture in the reinforcing mat underneath, and the giveaway is that it feels soft. This is why a real hail inspection is done by hand rather than by eye, and why photographs alone rarely settle it.

Occasionally hail goes all the way through. A puncture is unambiguous and it is the easiest version of this to identify from a photograph.

Check the Soft Metals Before the Shingles

Counterintuitive, and it is what an experienced inspector does first.

Vents, flashings, gutters and downspouts are thin, painted and unforgiving, so they record a hailstone’s size and the direction it came from far more legibly than a shingle does. A gutter with dents on the north face and none on the south tells you which way the storm ran, and that in turn tells you which slopes to look hardest at.

What Gets Mistaken for Hail

Plenty, and being able to rule these out is what makes an inspection worth trusting.

Blistering shows as small bubbles, a quarter inch across or less, caused by heat and asphalt quality rather than impact. Thermal splitting shows as long diagonal or horizontal cracks from the shingle shrinking and the deck moving, which is linear where hail is random. Manufacturing defects show as bands, spots or columns that repeat across slopes, and hail does not repeat in a pattern. Marring from installation or shipping leaves a ridge of bitumen around the edge of the mark, which hail does not.

Granule loss on its own is not damage. Every roof sheds granules from the day it goes on. Without a fracture in the mat it is weathering.

What Changes the Answer

Two roofs in the same storm can come out of it very differently, and the reasons are mostly not about the storm.

How old the shingle is

Haag’s own impact testing found eleven year old shingles the most susceptible of those tested, because they had gone thin and brittle. Age is the single biggest variable in whether a given stone leaves a mark.

Which slope it is

Hail arrives at an angle, so one or two slopes usually take the storm and the others do not. This is why a proper inspection covers every direction rather than the one somebody can reach.

What the shingle is made of

In the same testing, organic mat shingles were damaged at smaller sizes than fiberglass mat, and laminated shingles held out longest. Two houses on one street with different roofs are not running the same experiment.

Related Questions

How much of it does there have to be?

Carriers typically look for a number of impacts within a 10 foot by 10 foot test square. The square itself is published, in the hail damage assessment protocol carried by the National Roofing Contractors Association. The count is not, and that figure is carrier practice rather than an engineering standard. How much hail damage does it take to replace a roof? covers where the number comes from and what it cannot settle.

How do I know the damage is from this storm?

Colour. Freshly exposed asphalt is black and oxidises to grey over months. How can you tell old hail damage from new hail damage? covers the full set of indicators.

What do I do once I have found it?

Document it before anything else, in a form somebody who was not standing there can read. How do you get insurance to pay for a roof replacement in Oklahoma? covers what gets recorded and how.

What else on the property should be looked at?

Soft metal dents where a shingle only bruises, which makes a gutter or a vent hood the easiest surface on the property to read. What else should you check for hail damage besides the roof? covers the rest of the walk around.

See Also

The two answers next to this one are how much of it it takes, which is the question this one leads straight into, and whether the small hail that falls here most often counts.