Spring Storms: Hail Damage, How to Spot It and What You Need to Know

Spring Storms: Hail Damage, How to Spot It and What You Need to Know


Male hands holding hailstones

We all know springtime brings warmer temperatures and rain, but it also can bring severe storms that include wind and hail, both of which can wreak havoc on your commercial roof. While we can’t control the weather, we can take the time to better understand the different types of weather and how it can potentially impact our most expensive building assets.

How Hail Forms

Hail is a common accompaniment to the severe storms that are typical during the spring season. Hail, or hailstones, form when raindrops are carried upward by thunderstorm updrafts and into very cold areas of the atmosphere. There these raindrops freeze and grow in size while colliding with other raindrops that freeze onto the already frozen surface, adding layers. Hail falls to the ground when the updrafts can no longer support their weight either due to the hailstone’s size or to the weakening of the updraft. High winds can affect how much hail falls, its size, and even the angle at which it falls—all contributing to the potential damage to buildings and other structures.

Hail Impacts & Damage

Small hailstones can measure up to 1.75 inches in diameter, however very large hailstones can exceed 4 inches in diameter and fall at over 100 mph! That can result in some serious damage to your commercial roof. Hail impact can damage the roof membrane and cause cracks, punctures or dents that inevitably lead to leaks. A building with an aging roof and an older roof membrane may not be able to withstand a hailstorm. Since it’s accompanied by high winds, hail can also weaken the attachment bonds of the roofing system. Hailstone impact can also loosen or damage roof protrusions such as HVAC equipment, drains or other ductwork as well as dent or loosen gutters, metal copings, flashing or vent covers. If your commercial roof happens to have shingles, shingles could be missing, or the hail impact could leave a spotted pattern across the roof. Metal roofs could have dents or divots, while some types of flat roofs may have hail damage that appears as a spiral fracture pattern.

Some Common Signs

There are some common signs that hail damage has occurred and it’s best to remediate the situation as quickly as possible to not only maintain the aesthetics of the roof and façade of your building, but also to maintain the integrity of the building envelope.


  • Bubbles or blisters—This can indicate moisture trapped under the roof membrane.
  • Ponding—Hail can cause depressions which compact insulation and lead to ponding water.
  • Dents, divots, punctures, or cracks—This type of damage weakens the roof membrane.
  • Spots and markings—PVC, metal, and other single-ply roofs such as TPO and EPDM, can show circular marks, scuffs, or black spots from hail impact.
  • Lifted or peeled back roofing materials—The high winds and updrafts that accompany hail can make roof system components vulnerable.
  • Protrusions—Skylights and other protrusions can suffer cracked glass or damaged sealants.
  • Displaced rooftop equipment—Hail impacts can damage and/or loosen solar panels or HVAC system components.
  • Leaks—Water intrusion can lead to mildew, mold, rot, damage to insulation, wood and drywall.


What to Do

If you find evidence of impact damage after a hailstorm, it’s important to take action and protect your valuable building assets. Your first action step should be to contact your insurance company and to check your manufacturer’s warranty to see if hail damage is part of your coverage. The next step should be to have a professional commercial roof consultant perform an assessment. This assessment will involve examining both the exterior and interior of the building looking for signs of damage and water intrusion. The use of an infrared scan can also be helpful to detect water in the roof system. A professional roof assessment will give you a full written report along with photographic evidence of the damage to provide to your insurance company. Hailstone impact can be an inconvenience, but knowing how to identify the damage and the steps needed to remediate it will help to protect your investment.

Contact Us Today!

Technical Assurance can perform a building envelope assessment to assess the damage from spring storms and give you an actionable plan to ensure your investment lasts. Contact us today for a consultation.