Why Do Tornadoes Cause Pressure Damage to Windows?

Tornadoes form as a rapidly rotating column of air extending from a thunderstorm to the ground. The violent rotation lowers the atmospheric pressure at the tornado's core significantly. This localized low-pressure zone is the primary force behind the damage to structures. It creates a powerful vacuum effect that buildings and their components are not designed to withstand. The resulting pressure difference is one of the most destructive aspects of a tornado, acting on a home's entire exterior envelope at once.

Pressure damage often looks distinct from impact damage. Look for windows that are blown out from the inside, with glass shards found outside the home. Frames may be bowed or distorted, and interior doors might be blown off their hinges. This pattern of damage is a clear sign that a severe pressure differential occurred, which can also compromise the structural integrity of walls and the roof. Recognizing this pattern helps you understand the storm's forces when you report the damage.

• Windows shattered from the inside out.
• Glass fragments scattered on the ground outside the building.
• Window frames that are warped or pushed outward.
• Interior doors violently forced open or off hinges.
• A distinct popping sound you may have heard during the storm.
• Simultaneous failure of multiple windows on different sides of the home.

Structural damage and water intrusion from broken windows require a professional assessment. Local water damage pros can properly evaluate the safety of your home and begin necessary water extraction and drying to prevent mold. They can also perform a thorough water damage inspection and provide detailed documentation, which is crucial for your insurance claim. Policies vary, and your insurer decides what is covered. In a humid subtropical climate with hot rainy summers and an Atlantic hurricane season, fast drying is critical to avoid secondary damage like warped floors or mold growth inside walls.