Which Roofing System Performs Best Against Hail?
Not all commercial roofing systems handle hail equally. Here's a comparison of common systems by hail resistance.
Spray Polyurethane Foam: Best Overall
Foam's cellular structure absorbs and distributes impact energy — the best hail resistance of any commercial system. When hail damages a foam roof, repairs are straightforward: clean and apply compatible sealant or coating. Foam roofs also self-seal small penetrations if the topcoat remains intact around the impact point.
Modified Bitumen: Good
Granulated modified bitumen has reasonable hail resistance — the granules provide a protective surface layer that absorbs some impact energy. Smooth modified bitumen is more vulnerable to puncture than granulated versions.
Metal Roofing: Moderate
Metal panels dent under hail but rarely puncture — denting doesn't necessarily compromise waterproofing unless it damages seams or fasteners. However, large hail can cause significant cosmetic damage to metal panels.
TPO and EPDM: Vulnerable
Single-ply membranes are relatively thin and can be punctured by large hail. The seams are particularly vulnerable — hail impact near existing seams can cause delamination. Post-hail inspection and repair is critical for single-ply systems.
The Bottom Line
For hail-prone regions, spray foam's combination of impact absorption, seamless surface, and easy repairability makes it the most resilient commercial roofing option. A silicone-coated foam roof that receives hail damage can typically be repaired without compromising the overall system.
