This course is part of the Resiliency Academy

Explosion Relief Vents

Explosion relief vents are safety devices built into industrial buildings where excessive internal, explosion-incurred pressure is a risk; the vents work as a pressure relief. Explosion relief vents can help a building release pressure and survive a natural or man-made disaster involving explosions and excess internal pressure. Industries where combustible dust, gas, or chemicals are manufactured or used in manufacturing other products are at particular risk for explosions, which can be deadly to industry workers and impact the surrounding communities.

A key requirement of explosion relief vents is that they must be extremely strong to ensure that they remain intact and do not present a risk of pieces breaking off and becoming projectiles. Consequently, it is very important for explosion relief vents to be designed to meet National Fire Protection Association (NFPA) guidelines and to meet all relevant International Fire Code (IFC) building codes. Some vent designs can be tested and are easily reset after an explosion event.

Explosion relief vents are critical not only for protecting a structure during an explosion but also for keeping the building occupants and local communities safe from the potential impacts of an explosion.

Photo: Dustin Halleck Photography

The Chicago O’Hare Consolidated Rental Care Facility features explosion-relief vents designed to protect life and property in the event of smoke, fire, or an explosive blast.

Interior Wall Protection

In many cases, when we talk about resiliency, we think about how the external elements of a building are protected from weather extremes and other natural disasters. But resiliency also applies to the everyday use of interior spaces, such as high-traffic buildings like schools, hospitals, hotels, airports, and offices. In such spaces, the interior walls can be easily damaged by everything from machinery and heavy equipment to building occupants and pedestrians. Interior wall protection features, such as rigid sheet panels, corner guards, wall-protecting crash rails, door and frame protection, or even ergonomic handrails, can improve a building’s resiliency on a day-to-day basis and help minimize repair and maintenance costs while adding a customized aesthetic pop to a space. Certain features, such as rigid sheet coated doors, enhance fire resistance and are designed to meet the strictest fire codes, thus enhancing occupant safety in the event of a fire.

Photo: CPI Productions

Health-care facilities that utilize wall-protection products can withstand heavy use and abuse without showing wear and tear.

Photo: G. Lyons Photography

Interior wall-protection products are durable, impact resistant, and easy to clean to keep facilities looking good with minimal maintenance.

Photo: Joe Aker

Sugar Land Rehab Hospital in Sugar Land, Texas, incorporated interior wall protection into its design to enhance the beauty and durability of patient rooms. The wall protection is durable enough to hold up to the frequent cleaning requirements of the hospital’s environmental services staff.

Entrance Mats and Grids

Entrance mats and grids, while an often-overlooked feature of a building, are key in keeping building occupants safe while reducing the required maintenance of a building. They are designed to trap dirt, sand, and water so that the floor beyond the entrance remains safe, clean, and presentable. Entrance mat systems address the specific needs of high-traffic areas where building occupants are likely to bring in dirt and debris from the outdoors. Such mats are designed to scrape off dirt and trap it within the mat for future cleaning. Entrance grids can also be installed in high-traffic areas in or near building entrances to perform a similar dirt-catching function as mats, but they tend to trap and store more dirt than a mat. A stainless-steel grid is another option that requires almost no maintenance once it is installed and can be highly effective in protecting flooring from tracked-in dirt and moisture—thus protecting building occupants from potential slipping. The frequency of cleanings will depend on the amount of traffic a building sees on a daily basis and weather conditions that occur. Entrance mats and grids must be durable for cases when heavy machinery like scissor lifts, dollies, or vending machines need to enter or exit the building.

Entrance mats and grids aid in building resiliency by keeping the buildings clean and safe for occupants and also helping keep hallway floor surfaces free of water, thus preventing slip hazards.

Photo: Lester Ali

Entrance flooring solutions stop debris at a building’s entrance, as shown here at 3 World Trade Center in New York City. The right solution will trap dirt, snow, slush, and ice to reduce maintenance costs and protect the safety and security of occupants.

Designing for Resiliency

When we take a minute to step back and look at the risks associated with not designing for resiliency—such as the loss of life, extensive damage to property, and long-term economic toll on communities and businesses—it makes sense to incorporate some resilient design strategies whenever possible. Everything from being aware of the potential risks for the local environment to the specific topographical location can help. For example, is a project in a region known to flood? Or even if a flood hasn’t happened recently, are there rivers nearby that may present a risk? Are fires a hazard? Earthquakes? By taking the time to plan, design, model, and build for the possibility of extreme weather events and their impacts, architects and engineers can work together to create beautiful, resilient buildings that have a better chance of withstanding 100-year storms that occur year after year. In doing so, these buildings can help communities and businesses get back to work more quickly and with less financial strain. The first step in this process, however, is choosing architectural products designed for resiliency and incorporating them into the design early in the process.

Testing, Standards, and Ratings: The U.S. Resiliency Council (USRC)

Rating Systems

The U.S. Resiliency Council (USRC) has established a building rating system that assigns buildings one to five stars based on the dimensions of safety, monetary damage, and recovery time to regain basic functionality after an event.

Within the rating, safety focuses on the potential for occupants to safely escape the building unharmed. The damage rating concerns the estimated building repair costs after an event as a percentage of the building’s replacement costs. The recovery rating is expressed as how long it will take a building to regain basic function. This is an estimate of the minimum time required to repair and remove safety hazards from the building. In regard to earthquake hazards, the ratings are based on how intense the ground shaking is in terms of local building code requirements for a new building. At this point, there are no ratings for other hazards such as wind, wildfire, and flood; however, the USRC is in the process of developing them.

From highest to lowest, the rating categories are Platinum, Gold, Silver, and Certified, and they are detailed below according to USRC.¹⁰

The USRC Platinum rating represents the highest level of building performance and is intended to exceed modern code standards in terms of safety by protecting occupants against major injury and egress restrictions. Platinum-rated buildings are expected to suffer negligible damage (less than 5 percent of replacement cost) and allow functional recovery within a few days of a major seismic event. USRC Platinum is sought by owners who demand the highest level of asset protection and virtually uninterrupted functionality of their operations.

The USRC Gold rating represents a very high level of performance that is intended to exceed modern code standards in terms of safety by protecting occupants against major injury. Gold-rated buildings are expected to suffer only minor damage (less than 10 percent of replacement cost) and allow functional recovery within several weeks of a major seismic event. USRC Gold is sought by owners who demand high levels of asset protection and minimal disruption to their operations.

The USRC Silver rating is for buildings that, in addition to meeting the Certified standards, are expected to suffer significantly reduced damage (less than 20 percent of replacement cost) and allow functional recovery within a few months of a major seismic event. USRC Silver is awarded to buildings where limiting damage is an important consideration, such as for properties with commercial loans.

The USRC Certified rating is for buildings that have been evaluated by the USRC and comply with modern codes for performance in earthquakes. Certified buildings are expected to perform in a manner that will preserve the life safety of the occupants, limit damage to repairable levels under 40 percent of replacement cost, and allow functional recovery within a year of a major seismic event. Nearly 60 percent of most cities’ existing building inventories will not comply with this standard. USRC Certified signifies that a building is expected to achieve a level of performance consistent with new building standards.

Manufacturers and companies that rely on USRC ratings to certify their products understand just how important their contributions to resiliency efforts are, and the role they play in making communities safer and better able to withstand the impacts of natural and manmade disasters. As Gabriel Blasi, senior general manager at Construction Specialties, notes, “Our commitment to preparing our built environment to cope with natural disasters will be the platform on which we protect humanity and the places they frequent. The USRC can make this reality, and we are proud to support their efforts.”

Tests and Certifications for Resilient Building Products

Given the importance of resilient building design, the architectural products used in projects must meet the strictest performance standards. Testing is the first step toward ensuring that a performance standard has been met. Each architectural feature used in resilient design must pass key tests to ensure that it can perform above and beyond in extreme conditions. Let’s look at some of those tests.

EJCs are tested to ensure they will perform in a seismic event. Specific tests include the Seismic Corridor System (MACC) Cycle Test, Seismic Exterior Wall System (XLS) Cycle Test, Seismic Moat Cover Systems & Corners Cycle Test, and Seismic Tread and Riser Cycle Test.

Architectural louvers are tested and certified by the Air Movement and Control Association (AMCA), which is a third-party testing agency for the louver industry that tests and certifies louvers for air, water, and impact performance. AMCA 540 is a test method for louvers impacted by wind-borne debris for which the louver cannot become dislodged from the opening. This test ensures that the louver itself does not become a projectile. AMCA 550 is a test method for high-velocity wind-driven rain-resistant louvers and is tested to the following conditions: rainfall rate of 8.8 inches per hour tested to 35, 70, and 90 mph wind-driven rain for 15 minutes, and 110 mph wind-driven rain for 5 minutes. During all four tests, only 1 percent of total water sprayed is allowed through. According to AMCA 550, louvers that protect air intake openings in structures located in hurricane-prone regions, as defined in the International Building Code, shall comply with AMCA 550.¹¹

Interior wall-protection products and materials must meet governing building codes, such as the International Building Code (IBC) and National Fire Protection Association (NFPA), which mandate that all building materials meet the minimum of a Class C/3 rating.

Products such as handrails, crash rails, bumper guards, accent rails, corner guards, and wall coverings must be UL classified and labeled Class A/1. Fire-rated, flush-mounted corner guards should be UL labeled with 1-and 2-hour installation. Wall systems should be UL classified and labeled Class B/2. Doors should aim for being Intertek labeled for 20-minute wood fire doors and 60-minute wood mineral core fire doors with noncombustible stiles and rails. Class A/1 designates the material’s surface-burning characteristics when tested in accordance with UL723, ASTM E84, and CAN/ULCS101.2.

For explosion relief vents, fire and smoke vents must meet UL standard 793 for smoke and heat and should be IBC and IFC Section 910 and NFPA 204 compliant.

Entrance mats and grids must stand up to rolling loads.