Can 3/4-Inch Hail Damage a Roof?

On its own, a single three quarter inch stone will rarely fracture the mat of a sound modern shingle. Impact testing puts the damage threshold nearer 1 inch to 1.5 inches depending on the shingle’s age and type. But three quarter inch is the most common hail size in Tulsa, and peer-reviewed testing published in 2025 found that repeated sub-severe hail leaves a shingle up to ten times more susceptible to the storm that comes next. Arrowhead Roofing has worked Tulsa hail since 1987, and that second finding is the honest answer to this question.

Note: this is a general explanation of hail impact research. It is not a statement about any particular policy or claim. 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.

The thresholds below come from ice ball impact testing at terminal velocity, not from opinion.

The Short Answer

Two different questions get asked in the same words, and they have opposite answers.

Can one three quarter inch stone break a sound shingle? Usually not. The testing is fairly consistent on that and we are not going to pretend otherwise.

Can three quarter inch hail damage a roof? Yes, and the mechanism is cumulative rather than instantaneous. It strips granules. Granules are the layer that shields the asphalt from ultraviolet light, and a shingle that has lost them ages faster and fails sooner.

The 2025 Research That Changed This Question

This is new, it is peer-reviewed, and almost nobody in the trade has written about it yet.

Researchers at the Insurance Institute for Business and Home Safety published a study in Frontiers in Materials in September 2025 on what they call sub-severe hail, testing ice spheres at 0.7 inches and 1 inch against asphalt shingles. What they found:

• Shingles subjected to natural weathering plus sub-severe impacts were up to ten times more susceptible to damage.
• Weathered specimens showed a 108 percent increase in granule loss when later struck by large hail, compared with specimens that had not been through the small stuff.
• Average performance degradation was 47 percent, and up to 67 percent for some products.
• Cumulative granule loss from sub-severe hail was comparable to or greater than the loss from a single two inch hailstone impact.

Read that last line carefully, because it is the one that matters here. Twenty storms of small hail can take as much granule cover off a roof as one storm of the size everybody agrees is destructive. That is not a marketing claim. It is a measured result in a peer-reviewed journal.

And read what it does not say. It is not evidence that a single three quarter inch stone fractures a shingle mat. Anyone quoting this research to argue that would be overreaching, and we would rather draw the line ourselves than have it drawn for us.

What This Looks Like in Tulsa Specifically

An extreme weather report pulled for a single Tulsa address, built from National Weather Service Doppler radar, in situ reports and NOAA data, recorded the following over three years at one house.

Twenty of those twenty-four events were the size this page is about. And Oklahoma is not an ordinary hail state: NOAA’s Storm Prediction Center data has Oklahoma third in the country in 2025 with 369 hail events of an inch or larger, behind Texas and Kansas.

Put the local record next to the research and the picture is straightforward. Roofs here are not usually destroyed by one stone. They are subtracted from, repeatedly, by the size of hail that falls most often, and then finished off by a storm that a fresh roof would have survived.

When Small Hail Is Told It Could Not Have Done It

It happens, and it is worth understanding what is and is not being said.

A statement that three quarter inch hail could not have caused damage on a particular roof is a technical assertion about that roof. It may be right. But three quarter inch is the most common size that falls here, and if it categorically could not damage a roof, very few Tulsa roofs would ever carry a covered hail claim at all. That is worth noticing.

What moves a technical question is technical evidence: the condition and age of the shingle, whether the exposed asphalt is black or grey, how many impacts appear in a properly placed test square on each direction, and what the soft metals record about the size and angle of what fell.

We document those things and provide a written scope of work. We do not negotiate claims, and questions about what a policy covers belong with your carrier or your agent, and after that with the Oklahoma Insurance Department’s consumer assistance line on 1-800-522-0071.

What Changes the Answer

Four variables decide whether a given stone marks a given roof, and only one of them is the stone.

How old and how brittle the shingle is

The largest single factor. Laboratory testing found eleven year old shingles the most susceptible of those tested, because they had gone thin and brittle. A twenty year old roof and a two year old roof are not in the same storm.

How much small hail it has already taken

This is the 2025 finding, and it is the variable nobody used to count. Cumulative granule loss is measurable and it compounds.

Wind speed and angle

Hail driven hard arrives with more energy than hail that falls. The same stone size is a different impact in a different storm.

What the shingle is made of

Organic mat was damaged at smaller sizes than fiberglass in the same testing, and laminated shingles held out longest. Impact rated products are tested to a separate laboratory standard, which certifies performance against steel balls on new product rather than guaranteeing anything about real hail on a weathered roof.

Related Questions

What would the damage look like if it is there?

Circular bruises with a fracture in the mat that feel soft, plus granule loss and marks on the soft metals. What does hail damage look like on a roof? covers all of it.

How would anyone know it happened this year?

Freshly exposed asphalt is black and oxidises grey over months. How can you tell old hail damage from new hail damage? sets out the indicators and how precise they really are.

Does all this small hail shorten the roof’s life?

Measurably, and it is the reason lifespan tables travel badly to this part of the country. How long does a roof last? covers the material ranges and what northeast Oklahoma does to them.

See Also

The two answers closest to this one are how much damage a carrier typically looks for, and how any of it gets documented.