When it comes to the durability and reliability of metal roofing systems, wind load resistance is a critical factor that can significantly influence performance. High winds can pose a severe threat to the integrity of a roof, making it essential for architects, builders, and homeowners to understand how wind load impacts metal roofing systems and what can be done to enhance their resistance.
Metal roofing design and installation can be complex, and contractors, designers, and homeowners must pay attention to many small details, from local codes and regulations to adequate testing standards for your products. How to properly account for the different wind pressures your roof can encounter and to make sure your roof is installed properly to withstand them the best way possible is what we will explore in today’s blog. Additionally, learn more about this topic from leading experts at METALCON 2024!
What is Wind Load Resistance?
Wind load refers to the pressure exerted by the wind on a structure. It is a critical consideration in the design and construction of buildings, especially in areas prone to high winds, hurricanes, or tornadoes. Wind load can act in several ways:
- Uplift Pressure: Wind passing over the roof can create uplift pressure, attempting to lift the roof off the building.
- Lateral Pressure: Wind striking the side of a building can push against the walls and roof, causing lateral movement.
- Suction: Wind blowing across the roof can create suction forces that pull the roofing material away from the structure.
How Strong of a Wind can a Metal Roof Withstand?
The strength of wind that a metal roof can withstand varies depending on several factors, including the design, materials used, installation quality, and specific wind load requirements for the area. However, properly designed and installed metal roofs are known for their high wind resistance.
Many standard metal roofing systems are designed to withstand wind speeds of up to 140 mph. This is typically sufficient for most residential and commercial buildings in areas that do not experience extreme weather conditions. However, in regions prone to hurricanes, tornadoes, or other severe wind events, metal roofs can be engineered to resist higher wind speeds, often exceeding 160 mph. Some specialized systems are even rated to withstand winds of up to 180 mph or more.
Check out this series of informative videos provided by Sheffield Metals, a leader in the distribution of coated and bare metal products, as well as engineered standing seam metal roof (SSMR) & wall systems. CLICK HERE TO WATCH Episode 1 explaining what wind uplifts are and how wind affects metal roofing. Sheffield Metals will be exhibiting at METALCON in Booth #1823.
Factors Influencing Wind Resistance
Roof Design
- Roof Slope: Steeper slopes generally provide better wind resistance by reducing the uplift forces.
- Profile and Seam Design: Certain profiles, such as standing seam designs, offer superior wind resistance. Interlocking panels and concealed fasteners also enhance performance.
Materials
- Metal Type: Stronger metals like steel and aluminum are preferred for high-wind resistance. Thicker gauges of metal can also improve durability.
- Coatings and Finishes: Protective coatings can prevent corrosion and maintain the structural integrity of the roof over time.
Installation
- Fastening Systems: The type, quality, and spacing of fasteners are crucial. Properly spaced and high-quality fasteners prevent panels from detaching under high wind pressures.
- Sealing and Flashing: Proper sealing and flashing techniques prevent wind-driven water from penetrating the roof, which can lead to structural weakening.
How is Wind Load Resistance Tested?
Wind uplift testing is especially important, as it lets you know how much force a particular roof can withstand and how it will hold up in certain environments. Without understanding how to apply wind uplift testing data to your project, you may expose your metal roof installation to safety hazards and inept products.
A wind uplift test measures how much wind pressure a roof can withstand. Some of these tests may be designed to take a roof to failure, while some will measure a roof at a certain pressure to see how it holds up.
The key purpose of a wind uplift test is to ensure that a roof meets the minimum safety requirements for a particular area. It will inform manufacturers, suppliers, designers, building owners, and homeowners about the durability of their roofs in relation to wind pressure.
It’s important to look at the right products for your metal roof — ones that are rigorously tested for wind uplift and can reliably last in the future.
Learn From the Experts at METALCON – Register for METALCON’s Metal Roofing Education Sessions!
Who wouldn’t want to learn from the best! The industry’s “best of the best” will be teaching at METALCON. Attend the following educational sessions to learn all you need to know about wind load resistance and testing from leading experts working in the field:
Introduction to ANSI/MCA FTS-1 Test Method for Windload Resistance on Flashings
Learn from MCA Board Member and 25 year industry veteran, Bob Zabcik, as he introduces this test method and explains how it can be used by stakeholders to help prevent wind and water damage to metal roof systems over a closely fitted deck. Released in 2019, this test was developed by the Metal Construction Association through the SPRI canvassing process and its purpose is to ensure that metal flashings, particularly those along the eaves of a building, remain intact during a design-level wind event and was based on investigation programs conducted by the Roofing Industry Committee on Weather Issues (RICOWI). LEARN MORE
Holding Strength Comparison Between Short Rail and Direct Attachments on Racking Systems on Metal Rooftop for Solar Applications
Learning the difference between short rail and direct attachments on racking systems for metal roofing with solar applications is critical and could result in overall cost savings. As the S-5! Research and Development Director, session presenter Ricardo Barroso is responsible for managing the product development, compliance and application engineering teams, ranging from implementing testing and product development procedures to deploying products internationally. With more than 15 years of field experience, he will review testing results, engineering calculations, and the financial benefits of having a stronger uplift resistance system. In this session, get a complete understanding of uplift mechanical load tests, uplift local resistance mechanisms, racking system engineering calculations, racking system products, and the cost-effective analysis. S-5! has been the leading authority on metal roof attachment solutions since 1992. LEARN MORE
Metal Roofs Architectural Restoration/Preservation
Modernization of aging buildings can preserve and protect them while also maintaining historical integrity and accuracy. Todd Miller, president of Isaiah Industries and current president and chair of the Metal Roofing Alliance, brings his 40+ years of experience to have attendees understand why metal is an optimal choice for older structures. Metal roofs and walls can offer the benefits of low weight, flexibility, energy efficiency, wind resistance, fire safety, and easy solar attachment for the purpose of restoring or preserving aging structures. LEARN MORE
Each of these three sessions are eligible for 1 AIA LU HSW continuing education credit.
METALCON 2024 is October 30 – November 1 at the Georgia World Congress Center in Atlanta, Georgia. For 30+ years, METALCON has been the only annual tradeshow devoted exclusively to the application of metal in construction and design. With its dynamic exhibit hall, interactive education sessions and access to the Who’s Who of the industry — attendees count on METALCON to deliver the innovations, solutions, tools and expertise they need to turbocharge their businesses through the application of metal in the building envelope.