Hurricane Ties: Rafter-to-Wall Straps for Wind Uplift

We may earn commission from links on this page. Lead-form submissions are forwarded to local inspector partners. How we research and review.

Colorado is about as far from a hurricane coast as a state can be, yet framing crews along the Front Range install hurricane ties on new houses every day. The name comes from the coastal regions where these small galvanized steel connectors became standard, but the force they resist is universal: wind trying to lift a roof off its walls. In Boulder and along the foothills, strong downslope wind events can test that connection. This guide explains what hurricane ties are, how rafter-to-plate and truss-to-plate connectors resist uplift, why nailing schedules and the specified fasteners matter, how treated lumber affects corrosion, what inspectors can see, how retrofits work and what they tend to cost. Structural design is the job of the connector manufacturer, the building official and, where needed, a licensed engineer, so treat this as background rather than a design guide.

Part of our Structure & Exterior guide — start there for the full picture →

What Hurricane Ties Are and Why They Matter

Hurricane ties are metal connectors that fasten the bottom of a roof rafter or truss to the top plate of the wall below. On older houses, that joint was often made with a few nails driven at an angle, called toe-nailing. Toe-nails hold well enough against gravity, which pushes the roof down onto the walls, but they are weak against uplift, where wind pressure tries to pull the roof up and away.

When wind flows over a roof, it can create strong suction on the roof surface and the eaves, particularly at the edges, corners and ridge. If the uplift exceeds what the connections can hold, roof sheathing can peel, and in severe events entire roof sections can lift off. Once the roof structure is lost, walls lose their bracing at the top and the rest of the house becomes far more vulnerable.

FEMA’s Home Builder’s Guide to Coastal Construction states that in high-wind regions, special hardware is used for most framing connections and that toe-nailing is not an acceptable method for resisting uplift loads. It describes roof-to-wall connections as metal rafter ties or straps, sometimes called hurricane straps, that replace toe-nailing and provide added uplift resistance. The same guidance stresses a continuous load path: each connection from roof to foundation must be adequate for the loads expected to act on it, so a strong rafter tie only helps if the wall below is also tied down.

FEMA’s Building Science program, which studies how natural hazards affect structures, publishes much of the federal guidance on wind-resistant construction, including the coastal construction and wind retrofit guides referenced here.

Common connector shapes

Manufacturers sell many hurricane-tie designs, identified by model numbers in their catalogs. Two widely recognized families are often referred to generically as H1-type and H2.5-type ties.

• H1-type ties are typically larger, angled clips that wrap around one side of the rafter and down onto the face of the top plate. They are common on rafters and trusses where a stronger single-sided tie is needed.
• H2.5-type ties are typically smaller, flat-folded clips nailed to the side of the rafter or truss and the side of the top plate. They are very common on trusses in residential construction.
• Straps run from the rafter or truss over or around the top plate and down into the studs below, providing a more direct load path.
• Twist straps and saddle-style ties address specific geometries, such as a rafter crossing a beam.

Model numbers and rated capacities vary by manufacturer and are published in their catalogs. The right connector depends on the design loads, the lumber species and size, and whether the tie must also resist lateral loads. That is why connector selection belongs to the plans or the truss and engineering documents, not to guesswork on site.

Wind Uplift on the Colorado Front Range

The Front Range is not hurricane country, but parts of it are wind country. Boulder and the communities along the foothills, from the Golden area north toward Fort Collins, periodically experience downslope windstorms, where air accelerates down the east face of the mountains. Some of these events have produced gusts strong enough to damage roofs, topple trees and lift unsecured structures. Exposure varies a great deal from one neighborhood to the next, and areas closest to the foothills and on exposed ridges tend to see the strongest gusts.

Local building departments set design wind speeds and connection requirements based on adopted codes, so the requirements in a foothills community may differ from those on the eastern plains. Those code specifics change with each code cycle and local amendment. Homeowners with questions about whether their roof connections meet current requirements should ask the local building department or a structural engineer rather than relying on general rules.

Hail is the other Front Range roof story. A hail claim usually involves the roof covering, but a full tear-off for hail damage can also expose the tops of the walls and the rafter connections, especially at the eaves. That is one of the few moments in a house’s life when adding ties is relatively easy.

Nailing Schedules and Fastener Rules

A hurricane tie is only as strong as the fasteners holding it. Each tie is tested with a specific fastener type, size and count, and its published capacity assumes those fasteners are installed. Fewer nails, shorter nails or the wrong kind of fastener can reduce capacity well below the published rating.

FEMA’s connector guidance stresses several practical points:

• Hardware must be installed according to the manufacturer’s or engineer’s specifications.
• The correct number of the specified fasteners, in the specified length and diameter, must be used, and all nail holes should be filled unless reduced nailing is specified by design.
• Some specifications require non-standard nails, so the fastener called for may not be the common nail an installer has on hand.
• A connector nailed to only one member of a doubled top plate can fail under uplift. Nailing to both top plate members, or to the stud and plate, is the recommended approach.
• A strap over a rafter should extend above the rafter’s centerline or, for the strongest connection, completely over the rafter.

FEMA’s Wind Retrofit Guide for Residential Buildings adds that connectors are designed to use specific fasteners and specific situations, that manufacturers state how many and what size fasteners are required, and that connectors should never be bent or forced into place, because that compromises their strength. It also notes that longer fasteners may be needed when exterior sheathing covers the top plate, since connectors are designed around a minimum embedment into the plate.

Nails, not random screws

A frequent field problem is ties installed with whatever screws were handy, such as drywall screws or deck screws. These are not interchangeable with the specified fasteners. Many common screws are brittle compared with connector nails and can snap under shear loads, and their capacity in a given connector is often unknown. Some manufacturers do list specific structural screws as approved alternatives for certain connectors, but those are particular products, sized and tested for that use. Unless the connector documentation lists a screw, the specified nails are the safe assumption.

Another issue is short nails. Some installers use short nails sized for joist hangers in all the holes, even where a longer nail is required to penetrate both members. Short nails in a rafter tie can look correct but leave the connection well short of its rated capacity.

Corrosion and Treated Lumber

Most hurricane ties are galvanized steel. They are generally fine in dry, interior attic conditions. Problems arise where the connectors touch pressure-treated lumber or sit in wet locations.

Modern preservative-treated lumber often uses copper-based preservatives. FEMA’s coastal guidance names several, including alkaline copper quaternary (ACQ) and copper azole, and notes that connectors and fasteners used with these treated products must be compatible with the preservative per the manufacturer’s recommendations. It describes compatible fastener materials as hot-dip zinc-coated galvanized steel, stainless steel, silicon bronze or copper. In wet or exposed locations, heavier galvanizing or stainless steel connectors may be needed.

On a typical house, the rafter-to-plate connection is inside the attic and the top plate is usually untreated, so corrosion is less common there. It becomes more relevant on porches, decks, carports and other exposed framing where treated lumber and weather meet. FEMA’s retrofit guide recommends metal connectors at porch and carport beams and columns, and notes that column-to-foundation connectors should be rated for exterior exposure with a moisture barrier between the connector and concrete.

Signs of trouble include red rust on the connector, white powdery corrosion on galvanizing, flaking metal and nails that have rusted thin. Any connector that looks significantly corroded should be evaluated by a contractor or engineer.

The Load Path Below the Top Plate

A hurricane tie moves uplift from the rafter into the top plate. From there, the load still has to reach the ground. FEMA’s connector guidance describes the rest of that chain: stud-to-top-plate connections made with metal straps that wrap over the plate and replace toe-nailing or end-nailing, stud-to-stud straps or threaded rods that tie one story to the next, header straps that carry uplift from window and door headers to the jack studs, and wall-to-foundation connections made with metal brackets or bolts that tie studs and sill plates to the foundation.

In ordinary Front Range houses, much of that path is provided by structural sheathing nailed to the plates and studs, plus anchor bolts through the sill plate into the foundation. In higher-wind designs, additional straps and hold-downs appear. FEMA’s guidance notes that stronger connectors may be needed in areas subject to high winds or earthquakes, and that every connector in the chain must be adequate for its loads. A beefy rafter tie on a wall that is only lightly nailed at the bottom does not add much.

A quick look in your own attic

Homeowners comfortable entering their attic safely, walking only on framing and avoiding wiring and insulation disturbance, can sometimes see the eave connections near the access hatch. Things worth noting:

• Whether there is any metal connector at the rafter or truss heel, or only nails.
• Whether the connector has nails in its holes, or empty holes and a single fastener.
• Whether screws with bugle heads, typical of drywall screws, were used instead of nails.
• Whether the metal is bent, cut or twisted to fit.
• Rust, water stains or dark, soft wood at the eaves, which can point to roof leaks or ice dams.

Photos of what you find can help a contractor or engineer advise on next steps.

Related Roof-Edge Framing

Hurricane ties sit at the junction of several framing details that home inspectors and roofers often discuss together.

• Rafter tails. The ends of rafters that extend past the wall to form the eave are called rafter tails. They are exposed to roof leaks, ice dams and gutter overflow, and rot there can weaken the area right around the hurricane tie.
• Joist hangers. A joist hanger is a different connector that supports a joist end against gravity loads where it meets a beam or ledger. Hangers and ties often come from the same manufacturers and follow the same rule: use the specified fasteners in every required hole.
• Gable end walls. Gable ends can be weak points in wind. Bracing and tie-down details for gable walls are a separate structural topic.
• Trusses. Truss connections, including truss-to-truss and girder truss connections, are made with hangers specified by the truss designer. They should not be altered or cut in the field without the truss designer’s approval.

What Home Inspectors Check

The ASHI Standard of Practice directs inspectors to inspect structural components, including the foundation and framing, and to describe the roof structure. It also states that inspectors are not required to provide engineering analysis or offer an opinion about the adequacy of structural systems, and are not required to walk on attic framing concealed by insulation.

In practice, that means an inspector may note the presence or absence of visible roof-to-wall connectors at accessible areas of the attic, typically near the access hatch or along the eaves where insulation is shallow. Visibility is often limited. Insulation at the eaves frequently covers the tops of walls, and low-slope eaves can make the connections hard to reach. Inspectors may also note obvious issues: bent or forced connectors, missing nails, the wrong fasteners, or significant corrosion. A finding that ties appear missing or improperly installed is usually a recommendation for evaluation by a qualified contractor or structural engineer. Our structure and exterior inspection section covers what the framing portion of an inspection includes.

Retrofits and Typical Costs

Adding hurricane ties to an existing house ranges from straightforward to quite difficult. Where the attic is accessible and the eaves have enough room, ties can sometimes be added from inside the attic, though working at a low eave with insulation in the way is cramped. In many houses, the better access point is from outside, by removing soffits or by doing the work during a roof replacement when the sheathing at the eaves comes off.

FEMA’s wind retrofit guidance makes this exact point: homeowners pursuing roof-to-wall upgrades should consider doing them when retrofitting soffits or replacing the roof covering, while the connections are more easily accessible. That makes a planned reroof a sensible moment to ask about ties. Our guide to roof replacement cost covers how a reroof is priced.

Some general cost observations for the Denver metro, which are estimates that vary by house:

• Connectors themselves: typically a few dollars each for common ties, more for heavier straps or stainless steel.
• Adding ties during a planned reroof: usually a modest add-on, often in the hundreds of dollars to low thousands for an average house, mostly labor.
• Standalone retrofit from the attic or by opening soffits: more expensive and more variable, sometimes several thousand dollars, depending on access, insulation removal and soffit repair.
• Engineered retrofits: where loads are high or framing is unusual, an engineer’s design and inspection add cost but provide certainty.

A permit may be required for structural work, so check with the local building department. Get written quotes that list the connector models and fastener types. The main guide to hiring a home inspector explains how to find an inspector who looks closely at attic framing.

References

• Wind Retrofit Guide for Residential Buildings (FEMA P-804) — Federal Emergency Management Agency
• Home Builder’s Guide to Coastal Construction (FEMA P-499) — Federal Emergency Management Agency
• Building Science — Federal Emergency Management Agency
• ASHI Standard of Practice for Home Inspections — American Society of Home Inspectors

Buying a home near the foothills and wondering how well its roof is tied down? Contact us to be matched with a Front Range inspector who takes a close look at attic framing and roof connections.