Phone answered 24/7 · Portland, OR and nearby communities

Call 24/7: (503) 224-3149
Multnomah County Water ResponseWater Damage Help · Portland, OR

What Causes Roof Damage After a Major Hailstorm?

Last updated October 23, 2026

Call Now (503) 224-3149

The short answer

Direct Impact on Shingles and Tiles

The primary cause of roof damage is the physical force of hail striking the surface. This impact can crack asphalt shingles, split wooden shakes, or shatter clay or concrete tiles. Even metal roofing can sustain dents that compromise its weathertight seal. Once the outer layer is compromised, the underlying roof deck and interior materials become exposed to the elements, starting the path for water intrusion.

Smaller hail may only bruise shingles, damaging the fiberglass mat underneath without immediate visible signs. Larger hailstones, however, can punch holes directly through the roofing material. The damage often looks like circular fractures or random dark spots where granules have been knocked away. It's crucial to have a professional inspection after a storm, as some damage is not obvious from the ground.

Loss of Protective Granules

Asphalt shingles are coated with mineral granules that shield the asphalt from the sun's ultraviolet rays. A major hailstorm can scour these granules off the shingle surface. You might find granules accumulating in your gutters or downspouts after a storm. This granule loss exposes the underlying asphalt to accelerated weathering, making it brittle and more susceptible to cracking.

Without this protective layer, the shingle's lifespan is significantly reduced. The asphalt can dry out, crack, and curl at the edges. This degradation happens gradually but leads to premature roof failure. A roof inspection can assess the extent of granule loss and determine if repair or replacement is necessary to prevent future water damage.

  • Granules shield asphalt from UV degradation.
  • Hail knocks granules loose, exposing the asphalt layer.
  • Exposed asphalt becomes brittle and can crack.
  • Granule loss reduces the roof's reflective properties.
  • Gutters filled with granules are a key sign of damage.
  • This damage shortens the overall lifespan of your roof.

Damage to Flashing and Vents

Roof flashing, the metal strips around chimneys, vents, and valleys, is also vulnerable to hail. Direct hits can dent, bend, or puncture this critical waterproofing material. Similarly, plastic plumbing vents or attic fan housings can crack. Even small gaps or bends in flashing can create a direct channel for water to enter your home, bypassing the roof covering entirely.

Once flashing is compromised, water can run behind it and into your walls or attic. This type of leak is often hidden and can cause significant structural rot or mold growth before it's noticed. Checking these areas is a vital part of a post-storm inspection. A qualified roofer can reseal or replace damaged flashing to restore a watertight barrier.

Underlying Structural Weakening

Severe hail can damage the roof decking, the plywood or oriented strand board beneath the shingles. A forceful impact can fracture the wood or cause it to soften if water has already seeped in. A weakened deck cannot properly support the roof's weight or the weight of workers during repairs. This compromises the entire roof system's integrity and safety.

If the decking is compromised, it must be replaced before new roofing materials are installed. Ignoring this can lead to sagging roofs or even collapse in extreme cases. A thorough inspection from inside the attic, looking for signs of moisture, dark spots, or cracks in the wood, is essential after a major hailstorm.

How to Address Hail Damage

Your first step is a careful visual inspection from the ground, looking for obvious dents, missing shingles, or granule buildup. Avoid climbing onto a damaged roof yourself due to safety risks. Document all visible damage with photographs for your records and for a potential insurance claim. Then, contact a local roofing professional for a comprehensive assessment.

The roofer will provide a detailed report on the necessary repairs or replacement. If interior water damage has occurred, you will need water damage mitigation services to dry out the structure. Policies vary, and your insurer decides what is covered. It's wise to get the roof assessed quickly, as hidden leaks can lead to mold or rot within days.

  • Conduct a ground-level inspection and take photos.
  • Contact a qualified roofing professional for an assessment.
  • Have any interior water damage professionally dried.
  • Review your homeowner's insurance policy for hail coverage.
  • Keep all reports and documentation for your insurer.
  • Address repairs promptly to prevent secondary damage.

Talk to someone now

Every hour counts once water gets into floors and walls. One call starts the response.

Call Now (503) 224-3149

Frequently asked questions

Can hail damage lead to mold in my home?

Yes, if hail causes cracks or holes that let water inside, the resulting moisture can lead to mold growth within 24 to 48 hours. It's important to have any water intrusion dried thoroughly by water damage professionals to prevent this health and structural hazard.

How soon should I get my roof inspected after a hailstorm?

You should arrange for a professional inspection as soon as it is safe to do so. Hidden leaks can cause significant water damage to ceilings, walls, and insulation very quickly. Prompt action helps minimize repair costs and prevents secondary problems like mold.

What if I only see a few dents on my gutters?

Gutter dents indicate hail fell with enough force to cause damage. Your roof likely endured the same impact. Gutters can be replaced, but the roof's condition is more critical. A professional inspection is still recommended to check for less obvious damage to the roofing materials themselves.

Call Now (503) 224-3149