Hurricane Tie

A hurricane tie is a formed metal connector that links roof framing to the wall below. It is also called a hurricane clip, hurricane strap or, in some regions, a cyclone tie. Ties are generally made of galvanized or stainless steel and are nailed or screwed to both the rafter or truss and the wall top plate (or embedded in a masonry bond beam).

What it does

During high winds, suction on the roof surface and pressure inside the building try to lift the roof. A hurricane tie resists this uplift and also helps resist sliding, racking and overturning. It is one link in a continuous load path from roof deck to foundation.

Types

• Clips that wrap around the side of a rafter or truss and fasten to the top plate.
• Twist straps that turn 90 degrees so they can fasten to the face of a truss at its heel and the face of a wall stud or plate.
• Straps that run from framing down the wall and may continue to studs or lower floors.
• Embedded straps cast into concrete or grouted masonry walls, common in Florida and the Caribbean.

Performance in the field

FEMA's investigation of the 2011 tornadoes in Alabama and Joplin, Missouri found that metal connectors performed better than toenailed connections, but only when installed as the manufacturer specified. Common errors included wrong nail type or size, too few nails, and connectors on only some rafters. Because each product has a published load rating that depends on the fastener schedule, substituting nails can greatly reduce capacity.

Codes and retrofits

Building codes in hurricane-prone areas of the United States require uplift connections designed for local wind speeds, and the Florida Building Code addresses roof-to-wall attachment for both new construction and certain reroofing projects. Retrofit ties can be added to existing homes, often from outside while the roof covering is removed. Wind mitigation inspections in Florida record the type of connection (toenail, clip, single wrap, double wrap) because insurers offer credits for stronger connections.

Corrosion

In coastal areas, salt spray can corrode connectors over time. Heavier galvanizing or stainless steel is often specified where exposure is severe, and connectors should be compatible with treated lumber.