Making Buildings Safer Through Masonry
Tornado season underscores the importance of reinforced masonry wall systems.
By Dawn Henning
Tornado season typically peaks in April through June. But in January 2017, violent outbursts struck, featuring one of the largest tornado events to ever occur in winter. A spate of storms produced 79 confirmed tornadoes across the Deep South from Texas to South Carolina, resulting in the second-deadliest January outbreak on record.
According to the National Oceanic and Atmospheric Administration (NOAA), the United States averages more than 1,000 tornadoes per year – more than any other country. Annual insurance losses from U.S. tornadoes and thunderstorms range in the billions of dollars. The costliest event occurred in Tuscaloosa, Alabama, and nearby areas, in April 2011, totaling $7.8 billion in insured damages.
Although events of this magnitude account for only a small percentage of the total number of tornadoes that occur in the United States, the Tuscaloosa event – along with the tornado that struck Joplin, Missouri, a month later – initiated an ongoing review of building standards and closer scrutiny of materials used in new construction. It was determined that older homes are susceptible to tornado damage, but improved building standards can help save many new structures from destruction, thereby saving lives during future tornado activity.
In addition, since 2011, further study of a tornado’s path has indicated that greater damage occurs at the center of a tornado, with far less severe damage being inflicted on structures located near the edge. Even in the event of a rare EF-5 tornado, the greatest damage is limited to a narrow path, and most structures don’t experience a tornado’s highest wind speeds. All of this is good news, since the majority of U.S. tornadoes are EF-2-level storms or lower.
Improved building practices for tornado-resilient structures include correct construction for load transfer, along with proper connections between the roof, walls and foundation. This creates a continuous load path and decreases wind force vulnerability. Openings, such as windows and doors, including garage doors, are strengthened. This reduces the potential for pressurization, which can occur inside a building when these openings are compromised by wind damage. Pressurization can result in significant damage to or total destruction of a building.
How masonry can help
Reinforced masonry that is adequately connected to other building components can withstand high wind loads. It also offers greater protection against wind-blown debris, which can penetrate a building’s cladding and leave the structure at greater risk for internal pressurization. According to the Brick Industry Association, testing performed at Texas Tech University’s Wind Science and Research Center concluded that brick structures offer a much higher degree of protection from wind-blown debris than do buildings constructed with other forms of cladding.
One option for safer cladding is an oversized structural brick that is manufactured by General Shale, the Endurance RS4 structural brick. The company says the RS4 is designed to withstand strong winds and its oversized design yields safe, strong, sustainable and energy-efficient construction. “RS4” is an acronym representing Real Strong, Real Safe, Real Sustainable, Real Smart. General Shale says the Endurance brick is designed to bear higher loads, meet seismic requirements, and offer resistance, which can be reassuring for builders and homeowners in areas susceptible to high winds and tornadic events. These include commercial or government buildings such as hospitals, schools, courthouses and police stations.
Larger engineering and utility-size bricks have been used for reinforced masonry applications for many years. The Endurance RS4 uses this same proven engineering method, but can be installed with minimal labor and overall cost adjustments. This is a key benefit for builders, architects and contractors who need easy-to-install, efficient and cost-effective building solutions.
Endurance wall systems can also be used in conjunction with any type of interior wall construction (e.g., furring strips, non-load-bearing metal studs, hat channel, etc.) and insulation systems. The use of continuous rigid insulation, which reduces thermal bridging, is one of the most efficient methods of construction, both in terms of costs and energy savings. The combination of the Endurance RS4 and continuous insulation helps increase a building’s energy efficiency and can lower a structure’s Home Energy Rating System score.
Bottom line, the combination of Endurance RS4 structural brick with appropriate reinforcement between the wall system and roof creates a safe, strong and durable structure, providing greater peace of mind for property owners who live in areas at higher risk for significant weather events.