Hurricane Ties and Engineered Trusses: Improving Building Structure Performance in Hurricane-prone Regions

Hurricane Ties and Engineered Trusses: Improving Building Structure Performance in Hurricane-prone Regions

Table of Contents

What is Unique about Building for Hurricanes?

Hurricane-prone areas have stricter building codes than other regions due to the increased risk of damage from storms. Codes in these regions include additional requirements specifically tailored to mitigate the risks associated with hurricanes including high winds, storm surge, and windborne debris. Through the use of key features like engineered trusses and hurricane ties, these codes enhance the resilience and safety of structures and ultimately better protect occupants from the destructive forces of hurricanes.

Structural Design for Wind Loads:
Building codes in hurricane-prone areas account for higher wind load requirements. These codes are meant to ensure the design and construction of building structures with high success withstanding the dangerous wind forces associated with hurricanes. Codes in hurricane prone areas often include specifications for roof, wall, and foundation design to resist uplift and lateral forces. In short, many of the extra hardware and structural requirements specified in these codes are intended to help keep the roof from blowing off of your building. Using a truss system for roofing is one important strategy in regions with high hurricane risk (discussed in-depth below).

Building Materials Specifications:
Building codes in areas with high risk of hurricanes often include specific structural design elements tailored to withstand hurricane-force winds. This may involve specification for the use of stronger building materials like reinforced concrete or impact-resistant glass to enhance structural integrity. Wind speeds in a category 4 hurricane can reach 130-156 mph, which can turn everyday objects into dangerous projectiles capable of causing significant damage. 

Elevation and Foundation Requirements:
In coastal areas susceptible to storm surge, building codes may include elevation requirements to minimize flood risk. It might be required that building structures are raised above base flood elevation levels to reduce the likelihood of inundation and flood damage during hurricanes. Building codes may also have specific requirements for foundation design in hurricane-prone areas to ensure stability and resistance to storm surge and high winds. This could include specifications for deep foundations such as piles or piers to anchor structures securely to the ground. Take a look at our collection of holdowns for solutions to improve the shearwall-to-foundation and floor-to-floor connections in your building structure.

Building Envelope Integrity:
Building codes often emphasize the importance of maintaining the integrity of the building envelope to prevent water infiltration and wind damage during hurricanes. This may involve requirements for proper installation of weather-resistant barriers, sealants, and flashing to protect against water intrusion.

 

Hurricane Ties- Enhanced Framing Connections for Hurricane Prone Areas:

One of the most recognizable design interventions specifically for hurricane prone areas is the hurricane tie. These bent metal clips and straps are common in both wood and cold formed steel framing. By adding additional stiffness, hurricane ties effectively translate uplift loads from roofing to wall studs. Further paired with additional hardware like hold downs and strapping for floor-to-floor and shearwall-to-foundation connections, the load caused by wind uplift is effectively transferred to the building foundation. These clips provide the critical reinforcement needed to protect your structure in the event of extreme weather. The most common connection that comes to mind when thinking about hurricane ties is roof rafters-to-wall or truss-to-wall framing, but hurricane ties and additional hardware can also be used to reinforce floor-to-floor connections and floor-to-foundation connections. There are many variations of hurricane ties to provide high quality solutions for reinforcing all of the connections you may encounter in your construction project.

 


Framing example with metal strapping also used as hurricane ties.

Several Types of Hurricane Ties Available in our Online Store Pictured in Installation Scenarios:


CDHT1 Hurricane Tie


CDHT10S Hurricane Tie


CDHT10A Hurricane Tie

ClarkDietrich hurricane ties CDHT1, CDHT10S, and CDHT10A are designed to hold trusses on both sides to transfer uplift loads from roof framing members to the wall studs. Please refer to the product submittal sheets for CDHT1, CDHT10S, and CDHT10A for additional technical information including code approvals.


CDHT6 Hurricane Tie


CDHT8 Hurricane Tie

ClarkDietrich hurricane ties CDHT6 and CDHT8 are designed as high capacity hurricane ties that connect trusses to the top of wall plates in wood framing walls. Please refer to the product submittal sheets for CDHT6 and CDHT8 for additional technical information including code approvals.


CDHT2.5A Hurricane Tie


CDHT2.5T Hurricane Tie


CDHT2A Hurricane Tie


CDHT3 Hurricane Tie

ClarkDietrich hurricane ties CDHT2A, CDHT2.5A, CDHT2.5T, and CDHT3 are used as a connection between truss/rafters and walls to resist lateral and uplift conditions. Please refer to the product submittal sheets for CDHT2A, CDHT2.5A, CDHT2.5T, and CDHT3 for additional technical information including code approvals.

How Can the Use of Engineered Trusses Help Prevent Hurricane or Storm Damage to Structures?

Trusses contribute to building safety in hurricane-prone areas by providing a strong, stable, and wind-resistant roof structure. Their design and use, particularly when combined with hurricane ties, play a critical role in protecting buildings and their occupants from the devastating effects of hurricanes.

Some of the Advantages of Using Engineered Trusses:

Load Distribution:
Roof trusses are designed to distribute the weight of the roof evenly across the structure. This balanced distribution helps the building withstand both vertical loads (like snow or heavy roofing materials) and lateral forces (such as those exerted by high winds during a hurricane).

Strength and Stability:
Trusses are typically made from strong materials such as cold rolled steel studs or engineered wood, which provide superior strength and stability compared to traditional rafters. This increased strength helps the roof resist deformation and failure during extreme weather conditions. At US Frame Factory we fabricate trusses using cold-formed steel (CFS). See our article about truss design for more information.

Connection with Hurricane Ties:
Trusses are often used in conjunction with hurricane ties. The hurricane ties secure the trusses to the walls, preventing uplift forces from detaching the roof. This connection ensures that the entire roof structure remains intact, even in severe wind conditions.

Code Compliance and Design Standards:
In hurricane-prone regions, building codes often specify the use of trusses that meet certain design standards for wind resistance. Trusses designed to these standards ensure that buildings can withstand the expected wind loads during a hurricane, thus enhancing overall safety.

Reduced Construction Time and Errors:
Trusses are prefabricated, which means they are built off-site in a controlled environment like our production facility in New Iberia, LA and then transported to the construction site. This prefabrication reduces on-site construction time and the potential for worksite errors, leading to a more reliable and safer roof structure.

Resilience and Longevity:
A well-designed truss system contributes to the overall resilience of the building. It can withstand repeated stress from multiple storms over time, ensuring the long-term safety and durability of the structure. Cold formed steel is an excellent material for building longevity.

How are Engineered Trusses Designed and Assembled?

Roof trusses are constructed through a carefully orchestrated process that involves design, material selection, component fabrication, truss assembly, quality control, transportation, and installation. This systematic approach ensures that the trusses meet structural requirements and contribute to the overall safety and stability of the building's roof system.

Step 1 - Design and Engineering:
The construction process begins with the design and engineering of the roof trusses. Structural engineers consider factors such as building dimensions, roof pitch, anticipated loads (such as snow and wind), and local building codes to create a truss design that meets structural requirements.


We fabricate custom trusses that meet the demands and goals of your specific project.

Step 2 - Materials Selection:
Once the design is finalized, suitable materials are selected for the trusses. Common materials include wood (such as douglas fir or southern pine), engineered wood products (such as glue-laminated lumber varieties), or metal (such as steel or aluminum). The choice of material depends on factors like cost, availability, and structural requirements. Compared to wood, the light gauge steel trusses we manufacture at US Frame Factory can achieve longer spans and enable complex roof shapes.

Step 3 - Fabrication:
Trusses are typically fabricated off-site in a specialized manufacturing facility like our shop at US Frame Factory. The fabrication process involves cutting and assembling the individual components of the truss according to the engineered design. The beginning of this process is cutting timber or metal members to precise dimensions. Once the individual truss components are fabricated, they are assembled into the final truss configuration.
The final assembly process requires laying out the components on a flat surface according to the truss design and then connecting them together using metal tie plates or other bent sheet metal brackets. The skewable angles available in our online shop are a great product for hip truss roof configurations where there are 45 or 135 degree angles. Final assembly of the engineered truss is not complete until the specified number of fasteners have been used to secure each connection.


Prefabricating trusses in our manufacturing facility helps ensure that all members are cut to exact lengths and all connections have the fastener type and quantity specified by your project's structural engineer.


Skewable angles enable off-angle connections such as 45 and 135 degrees.


Example of building structure with multiple engineered truss designs and non-standard angle features.

Step 4 - Quality Control:
Throughout the construction process and after the completion of assembly, quality control measures are implemented to ensure that the trusses meet the required specifications and standards. This may include inspections of the materials, fabrication process, and referencing construction documents to identify any defects or deviations from the design.

Step 5 - Transportation:
Once assembled, the completed trusses are transported to the construction site. Depending on their size and weight, trusses may be transported using flatbed trucks or other specialized vehicles. Care must be taken during transportation to avoid damage to the trusses. 


Here at US Frame Factory, we ship anywhere in the US and offer both competitive shipping rates and pick-up options. Contact us at sales@usframefactory.com or (337) 282-5877 for additional details.

Step 6 - Installation:
At the construction site, the trusses are lifted into position and installed on the building's walls or support structure. Panel clips specifically designed as lift points for prefabricated panels can be used to improve worksite safety and efficiency. Once in position, trusses are securely attached to the wall structure using appropriate fasteners and connectors, such as hurricane ties or truss hangers. Proper alignment and spacing are crucial to ensure the structural integrity of the roof system. Products such as truss spacers can be used for lateral bracing and to achieve accurate spacing of truss members. In some cases, it may also be beneficial to use load share clips to transfer loads between two trusses.


Truss spacers used for lateral bracing and accurate spacing (24” on center).


Load share clips (available in multiple size configurations) help transfer loads between two back-to-back trusses.


Fully installed truss systems ready for roof sheathing.

Step 7 - Roof Sheathing and Finishing:
Once the trusses are installed, roof sheathing (such as plywood or oriented strand board) is applied to provide a solid substrate for the roof covering, such as shingles or metal roofing. Additional finishing touches like soffits may also be added to complete the roof assembly, but keep in mind that for best access all trim work should be installed last after the installation of structural connections is complete.

Additional Questions?

For additional details about our in-house engineering capabilities and different truss types make sure to check out our article on engineered metal trusses.

Check out our online shop with many different hurricane ties, framing clips, and other custom hardware such as truss accessories. Our wide variety of products enable the efficient construction of durable buildings in all regional climates throughout the US, not just hurricane zones.

For inquiries regarding your specific construction project, please contact us at sales@usframefactory.com or (337) 282-5877 for estimates, troubleshooting, or additional product details.

 

 

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