Spring in Dallas-Fort Worth brings supercell thunderstorms capable of dropping baseball-sized hail. When a roof sustains catastrophic hail damage, the shingles and underlayment fail. What happens next depends entirely on the type of insulation resting beneath the wood decking.
The Fiberglass Sponge
If hail breaches a roof over a traditional vented attic, rainwater pours directly onto the blown-in fiberglass. Fiberglass acts like a massive sponge, absorbing the water, compressing under the weight, and crushing your ceiling drywall until it collapses into the living room. The insulation is completely destroyed and must be extracted.
The Foam Shield
If the attic was encapsulated with spray polyurethane foam applied directly to the underside of the roof deck, the foam acts as a secondary rigid barrier. While open-cell foam is not technically waterproof, its sheer dense mass drastically slows water intrusion, often preventing a sudden catastrophic ceiling collapse and buying you time to tarp the roof. Closed-cell foam is completely waterproof and stops the leak instantly.
Always demand that your roofing adjuster inspects the attic insulation after a hail event. If batting got wet, it will grow toxic black mold within 72 hours. The insurance company is legally obligated to pay for a full industrial extraction and replacement.