Upgrade to Wind-Resistant Roof Cover

05/03/2023

Why do they matter?

The roof covering is one of your house’s first and most important defenses against hurricane winds and wind-driven rain, and unfortunately, it’s also often the weakest part of the roof.

What do I need to know?

• Common residential coverings include asphalt shingles, concrete and clay tiles, and metal panels.
• High-wind rated shingles, metal roof or metal panel/standing seam metal roof system, or concrete and clay tile are resilient roof coverings when installed along with the proper connections per manufacturer’s instructions for increased wind loads.
• Many hurricane-prone areas are also prone to hail. Look for wind and impact-rated roof coverings to protect roof coverings from wind and hail damage.

Types of roof coverings

Asphalt shingles

Two of the most common causes for damage to asphalt shingle roof coverings in high-wind events are improper installation and use of shingles that are not rated for the wind speeds identified in the building code. It is essential to understand the wind-resistance ratings and special installation methods for asphalt shingles in high-wind, coastal regions.

Pros:

• Relatively low cost, lightweight, and easy to install
• Good fire resistance (usually Class A)
• UL 2218 Class 3 and 4 impact resistance is available and should be used in hail regions
• Available with wind warranties up to 130 mph if installed per manufacturer's high-wind requirements
• Asphalt shingles should be installed following FEMA 499 Technical Fact Sheet No. 7.3, which explains asphalt shingle installation, wind-resistance ratings, and weathering and durability

Cons:

• Aging and weathering may decrease effectiveness in high winds and impact resistance

Considerations:

• If you have an old roof replaced, your contractor should remove the existing shingles and underlayment rather than install new shingles. This approach allows the contractor to inspect the sheathing and make any needed repairs.
• For the highest level of wind-rated shingle, look for shingles that are rated to ASTM D3161 Class F or ASTM D7158 Class H. For the highest level of impact protection, look for shingles that meet UL 2218 Class 4.
• Nails for homes within 3,000 feet of saltwater should be hot-dip galvanized or stainless steel.
• Use six nails per shingle for three-tab shingles and follow manufacturer’s instructions when using architectural shingles.
• Ensure the shingles do not extend more than ¼” beyond the roof’s edge for a square drip edge.
• Your roofing designer should obtain manufacturer information on bond strength and nail pull-through resistance, and use products with the upper ranges of available strengths.

Metal

Pros:

• Attractive and relatively lightweight
• Last up to 40 years
• May have a Class A or B fire rating

Cons:

• Typically more expensive than asphalt shingles
• Cosmetic damage from hail may cause permanent dimples

Considerations:

• If installing a metal roof system, FEMA 499 Technical Fact Sheet No. 7.6 provides guidance on selecting and installing panel or shingle system.
• For metal roofs, use clips or cleats instead of exposed fasteners because they aren’t exposed to weather and they allow the metal to expand and contract reducing the opportunity for buckling
• If exposed fasteners are used on metal roofs, they should be corrosion resistant and penetrate the sheathing

Slate

Pros:

• Can last three times longer than shingles

Cons:

• Expensive and very heavy
• Some roof structures are unable to support slate
• Additional installation cost

Tile

Pros:

• Popular in some areas
• Available in concrete or clay
• Concrete tiles are more durable and can last more than 30 years

Cons:

• Performance in hail storms varies by type
• Clay tiles are brittle and can be easily chipped or broken
• Tiles are heavy, and some structures are unable to support the weight
• Can take longer to install making labor costs more expensive

Considerations:

• On tile roofs, use wind clips or storm anchors in high wind or seismic areas
• On tile roofs, two screws per tile give the highest wind uplift resistance and will help the tile resist shifting.
• Installation is critical in high wind areas when using clay or concrete tile, especially on the hip and ridge tiles

Wood shingles and shakes

Pros:

• Made from cedar, southern pine, or other woods
• Attractive appearance
• Perform moderately well against hail

Cons:

• May not be fire-rated unless treated with a fire retardant
• Some local codes limit their use

All other roof coverings

• All roof coverings, regardless of type, should be installed in accordance with the manufacturer’s installation instructions for the appropriate design wind speed.

Where do I start?

• Contact a licensed roofer in your area to evaluate your existing roof and determine what can be done to make it more resilient.
• Check local code requirements for roof repair or replacement criteria. Your local building official should be able to provide additional recommendations.

More Resources:

• FLASH. Resilient Design Guide: High Wind Wood Frame Construction Edition.
• FLASH. Volunteer Guide Mitigation for High Wind Events.
• FEMA. Secure Metal Siding and Metal Roofs.
• FEMA. Secure Composition Shingle Roofs.
• FEMA P-804, Wind Retrofit Guide for Residential Buildings.
• National Roofing Contractors Association (NRCA) Steep-Slope Roofing Manual