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Why Is My Roof Losing Granules After a Hailstorm?

Last updated October 25, 2026

The short answer

What Are Roof Granules

Roof granules are small, stone-like particles embedded in the surface of asphalt shingles. They shield the shingle from sun and weather, and they add fire resistance. During a hailstorm, the force of ice impacts can dislodge these granules, leaving bare spots.

Some granule loss is normal over time, especially on an older roof. But after a hailstorm, you may see piles of granules in gutters or on the ground. That signals the shingles took a direct hit and may be compromised.

Why Hail Causes Granule Loss

Hailstones strike with enough force to fracture the mineral surface of the shingle. The impact can also crack the shingle itself, exposing the fiberglass mat underneath. When the mat is exposed, water can seep in more easily, and the roof ages faster.

The angle of the hail and the size of the stones affect how much damage occurs. A direct hit on a steep slope can knock off more granules than a glancing blow. You might also notice bruising or small dents in the shingle, which are signs of impact damage.

If you live in Detroit, you know hailstorms can come with strong winds. Those winds can drive hail at an angle, increasing the chance of damage.

  • Granules in gutters or downspouts
  • Bare spots or shiny patches on shingles
  • Cracks or splits in the shingle surface
  • Dents or bruising from hail impact
  • Exposed mat or felt under the granules

When to Call the Pros

You should act quickly if you see granule loss combined with cracks or exposed mat. That kind of damage can let water into your roof deck and attic. Local water damage pros can inspect the roof and attic to check for moisture and structural issues.

The pros will assess the extent of the damage and recommend whether repairs or a full replacement makes sense. If the shingles are old and brittle, a patch may not hold. They can also check for hidden water damage in the roof deck or insulation.

If water has already entered your home, the pros can help with drying and dehumidification to prevent mold and rot.

What Roof Repair Involves

Repairing hail-damaged shingles usually involves removing the affected shingles and installing new ones. If the damage is widespread, the pros might suggest a full roof replacement. The choice depends on the age of the roof and the extent of the granule loss.

The pros will also inspect the underlayment and roof deck for water damage. If moisture has soaked into the wood, they may need to dry it out or replace sections. This helps prevent future leaks and keeps your home safe.

Costs vary depending on the roof size, the type of shingles, and the amount of damage. A repair might be a few hundred dollars, while a full replacement can be several thousand. The final price depends on the specific conditions of your roof.

Preventing Further Damage

After a hailstorm, you can reduce immediate risk by checking your attic for water stains or dampness. If you find any, place a bucket under the leak and call the pros right away. Keeping gutters clean helps water flow off the roof instead of pooling.

You can also trim overhanging branches that might drop debris onto the roof during a storm. But don't walk on a damaged roof yourself, as it can be slippery or structurally weak. Leave the inspection and repairs to the pros.

Policies vary, and your insurer decides what is covered. Check your policy to see if hail damage is included, and document the damage with photos before any work begins.

Water damage does not wait

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Frequently asked questions

Is granule loss always a sign of roof damage?

Not always. Some granule loss happens naturally as shingles age, especially in valleys or near edges. But after a hailstorm, heavy granule loss usually means the shingles took a hit. Look for cracks or exposed mat, and if you see them, call the pros.

Can I just sweep the granules back onto the roof?

No. Sweeping granules back won't reattach them. The protective coating is gone, so the shingle remains exposed. You need to repair or replace the damaged shingles. The pros can determine whether a patch is enough or if a larger repair is needed.

How soon should I get the roof inspected after hail?

You should act quickly, within a few days if possible. Delaying can let water seep into the roof deck and cause more damage. The pros can inspect the roof and attic to find hidden moisture. Early action helps prevent mold and structural issues.

Call Now (313) 766-2970