Compliance with FEMA and ICC standards is not just a regulatory requirement—it’s a critical aspect of responsible building practice. Tornadoes and hurricanes cause severe damage, posing significant risks to structural integrity and human safety. Without the right wind and impact-resistant windows and doors, the entire structure of a storm shelter becomes compromised.
At Insulgard, we understand the necessity of rigorous testing and compliance with the highest standards to guarantee the safety of your storm shelter projects. This comprehensive guide explores key aspects of tornado and hurricane safe room testing, relevant requirements, and how Insulgard security products meets and exceed these stringent standards.
Key Impact Resistant Testing Standards and Regulations
- FEMA-361: Sets the performance criteria for tornado safe rooms.
- International Building Code (IBC): Specifies building codes for schools and critical facilities in high-wind zones.
- ICC-500: Provides guidelines for storm shelter design and construction.
Impact-resistant windows and doors designed to FEMA-361 and ICC-500 standards are tested to withstand high wind pressures and resist penetration by debris, helping you maintain compliance, reduce the risk of structural failure, and ensure the safety of the occupants sheltering within.
Key Aspects of ICC-500 Certification
- Design Criteria: Specifies the required structural design to resist wind pressures and impact.
- Construction Materials: Details the types of materials that should be used, including impact-resistant windows.
- Testing Protocols: Defines the tests that materials and structures must pass to be certified.
DESIGN AND CONSTRUCTION GUIDANCE FOR COMMUNITY SAFE ROOMS. FEMA P-361, SECOND EDITION, AUGUST 2008
Comparison of Debris Impact Test Requirements for Tornadoes and Hurricanes
Tornado Safe Room Missile Testing Requirements
| GUIDANCE, CODE, OR STANDARD CRITERIA FOR THE DESIGN MISSILE | HORIZONTAL DEBRIS IMPACT TEST SPEED (MPH) | LARGE MISSILE SPECIMEN | MOMENTUM AT IMPACT (LBF-S)+ | ENERGY AT IMPACT (FT-LBF)+ |
|---|---|---|---|---|
| DOE-STD-1020-2002 | 25 mph | 3,000-lb auto | 3,240 | 67,710 |
| 75 mph | 75-lb pipe | 257 | 14,110 | |
| 150 mph (maximum) | 15-lb 2×4 | 103 | 11,288 | |
| 100 mph (maximum) | 15-lb 2×4 | 68 | 5,017 | |
| FEMA 320/FEMA 361 | 100 (maximum) | 15-lb 2×4 | 68 | 5,017 |
| 80 (minimum) | 15-lb 2×4 | 55 | 3,210 | |
| ICC-500 Storm Shelter Standard | 100 (maximum) | 15-lb 2×4 | 68 | 5,017 |
| 80 (minimum) | 15-lb 2×4 | 55 | 3,210 | |
| IBC/IRC 2006, ASCE 7-05, Florida and North Carolina State Building Codes, ASTM E 1886/E 1996 | N/A | None | N/A | N/A |
Hurricane Safe Room Missile Testing Requirements**
| GUIDANCE, CODE, OR STANDARD CRITERIA FOR THE DESIGN MISSILE | HORIZONTAL DEBRIS IMPACT TEST SPEED (MPH) | LARGE MISSILE SPECIMEN | MOMENTUM AT IMPACT (LBF-S)+ | ENERGY AT IMPACT (FT-LBF)+ |
|---|---|---|---|---|
| DOE-STD-1020-2002 | 50 | 15-lb 2×4 | 34 | 1,254 |
| FEMA 320/FEMA 361 | 128 (maximum) | 9-lb 2×4 | 53 | 4,932 |
| 80 (minimum) | 9-lb 2×4 | 33 | 1,926 | |
| ICC-500 Storm Shelter Standard | 102 (maximum) | 9-lb 2×4 | 42 | 3,132 |
| 64 (minimum) | 9-lb 2×4 | 26 | 1,233 | |
| Florida State Emergency Shelter Program (SESP) Criteria and EOC Design Criteria | 50 (EOC recommended) | 15-lb 2×4 | 34 | 1,254 |
| 55 (EHPA recommended) | 9-lb 2×4 | 23 | 911 | |
| 34 (EHPA minimum) | 9-lb 2×4 | 14 | 348 | |
| IBC/IRC 2006, ASCE 7-05, Florida and North Carolina State Building Codes, ASTM E 1886/E 1996** | 55 | 9-lb 2×4 | 23 | 910 |
| 34 | 9-lb 2×4 | 14 | 348 |
+ lbf-s = pounds (force) seconds and ft-lbf = foot pounds (force)
** Hurricane missile testing requirements in these codes and standards only apply in the windborne debris regions (defined in the code/standard) and not throughout the hurricane-prone region
N/A = Not applicable
International Building Code (IBC) Requirements
Established in 2000 by the International Code Council (ICC), the International Building Code (IBC) was a significant step towards standardizing building codes across the United States and many other countries to address safety considerations for extreme weather events like tornadoes and hurricanes.
IBC 2015 and later versions require all K-12 schools and emergency fire/police/call center facilities located in 250-mph wind zones to build storm shelters that meet ICC-500 certification standards, including the ability to withstand an EF5 tornado.
The 2015 and later versions of the International Building Code (IBC) include strict requirements for wind load calculations, enhanced impact-resistant glazing standards, and mandatory missile impact testing for windows and doors in high-risk areas.
Following FEMA Regulations
The Federal Emergency Management Agency (FEMA) has also established regulations, particularly FEMA-361, that set the gold standard for tornado and hurricane safe room construction. Compliance with these regulations ensures that safe rooms provide the highest level of protection.
FEMA-361 Overview
- Performance Criteria: Safe rooms must withstand 250-mph wind speeds.
- Impact Resistance: FEMA tornado windows must resist large debris impact.
- Occupant Safety: Safe rooms must provide a safe environment for occupants.
Importance of Missile Testing
Missile testing, which simulates the impact of debris propelled by high winds, is a critical component of evaluating the effectiveness of impact-resistant products.
Missile Testing Process
- Selection of Projectiles: Common debris such as lumber and metal rods are used.
- Impact Simulation: Projectiles are launched at high speeds to replicate tornado and hurricane conditions.
- Assessment: The integrity of the impact-resistant products is evaluated to ensure they meet required standards.
Testing Protocols for Storm Shelters and Safe Rooms
Rigorous testing protocols are required before certifying that storm shelters and safe rooms provide necessary protection.
Key Testing Protocols
- Wind Pressure Tests to simulate the force of high-speed winds on the structure.
- Debris Impact Tests to assess the ability of materials to withstand flying debris.
- Structural Integrity Tests to evaluate overall strength and durability.
Impact of Tornados and Hurricanes
Tornados and hurricanes are two of nature’s most destructive forces. They can generate winds exceeding 250 mph, causing catastrophic damage to buildings, infrastructure, and, most importantly, human life.
The Devastation
- Wind Damage: High-speed winds rip roofs off buildings, shatter windows, and cause structural failures. For example, the Joplin tornado in 2011, an EF5 tornado, tossed vehicles a mile away and destroyed entire neighborhoods, demonstrating the necessity of robust building designs.
- Debris Impact: Flying debris propelled by tornado and hurricane winds can become deadly projectiles, capable of penetrating standard building materials. The EF5 Moore, Oklahoma tornado in 2013 saw debris impacts that compromised the integrity of many buildings—even steel-reinforced concrete structures—highlighting the importance of robust, impact-resistant products.
- Flooding: While primarily a concern for hurricanes, flooding can also result from the aftermath of a tornado, compounding the damage. Hurricane Katrina in 2005 caused extensive flooding, in addition to debris and wind damage, underscoring the multifaceted threats posed by extreme weather events.
Windows and Doors Are the First Line of Defense
Wind-and-impact-resistant tested windows and doors top the list of safety requirements for structures in the 250-mph wind tornado and hurricane zones.
Here’s why: when rain and wind enter a building through broken windows or other openings, it creates a specific type of pressure known as “positive internal pressure.”
This pressure creates a chain reaction of events involving:
- Wind Force: High-speed winds exert pressure on the exterior of a building. When windows or walls are compromised, the wind rushes inside, pushing air into the building’s interior. This phenomenon increases internal pressure.
- Pressure Differential: As the pressure differential between the outside and inside of the building increases, doors and walls bow outward or even collapse, leading to further structural damage.
- Structural Damage: As the internal pressure builds, walls, roofs, and floors weaken. The added stress causes vital components to fail, leading to partial or complete collapse of the building structure.
- Debris Displacement: The force of the wind entering the building turns everyday items into dangerous projectiles. Glass shards, furniture, and building materials are hurled around, causing additional injuries and damage.
- Flooding: The pressure differential can also push rainwater into the building, leading to flooding. Water intrusion exacerbates damage to the structure, increasing the risk of electrical hazards and mold growth.
Evolution of Safe Room Standards
Over the years, the approach to building safe rooms and storm shelters has evolved significantly. As understanding of wind dynamics and impact forces improved, so did the standards for safe rooms.
Key Milestones
- Early Safe Rooms: Simple structures designed to withstand moderate winds lacked the sophisticated engineering and materials used today, often resulting in inadequate protection when storm intensity ramped up.
- Advanced Designs: The incorporation of reinforced concrete, steel, and impact-resistant windows and doors mark a significant improvement in the ability to withstand high wind pressures and debris impacts.
- Modern Standards: Adoption of rigorous regulatory frameworks that include impact-resistant test protocols ensures that safe rooms can reliably endure the most extreme conditions.
Insulgard Security Products: Meeting and Exceeding Standards
Insulgard provides the highest quality impact-resistant products that meet and exceed industry standards. Our products are certified by UL and undergo rigorous testing to ensure they provide optimal protection during extreme weather events.
Why Choose Insulgard?
- Proven Performance: Our products have been tested to the highest standards.
- Comprehensive Solutions: From windows to doors, we offer a range of impact protective systems products, systems, and solutions to meet your needs.
- Expertise and Experience: With nearly 50 years of experience in the industry, we understand the unique challenges of protecting against extreme weather.
Request a Quote
Interested in learning more about how our impact-resistant products can safeguard your facility? Contact us today to request a quote and discuss your specific needs. Our team of experts is ready to assist you in selecting the right products to ensure maximum protection.
