Standing Up to the Storm Requires Taking It from the Top Down
Hurricanes Andrew and Opal demonstrated that the integrity of the roof is key to a structure's ability to resist hurricane wind forces. Looking at the performance of materials from the roof down, investigators learned that:
- Asphalt shingles - Often failed due to holes crated by staple guns. Nails held better than staples - if nails were properly placed.
- Clay roof tiles - Resisted wind forces better than asphalt shingles, but were apt to shatter if hit by flying debris.
- Concrete roof tiles - Suffered similar damage as clay roof tiles from debris, but were more resistant to shattering than clay tiles.
- Asphalt gravel roofs - If not well maintained, wind flaked off layers of asphalt exposing sub-layers.
- Plywood sheathing - Most failures were due to inadequate nailing.
- Particle board - Does not provide good base for the attachment of surface roofing materials.
- Gables - Were more prone to failure than hip roofs. Gables constructed of concrete masonry fared much better than frame construction. Inadequate attachment to walls and inadequate lateral support caused many failures of gables, particularly wood frame gables.
- Concrete block walls - Performed well. Concrete masonry construction was more forgiving of poor craftsmanship than wood frame construction.
- Wood frame walls - Performed poorly unless well designed and constructed.
- Windows and doors - Need to be carefully installed. Windows must be protected with hurricane shutters.