In the face of violent weather, you want to rest assured that your property and any people residing within it are safe. In this case, impact-resistant windows are non-negotiable, and many construction professionals, design specialists, and property owners have already put their trust in reliable and resilient Insulgard security products.

All Insulgard products undergo substantial testing and certification to ensure they offer robust protection. Our STORMDEFEND TTH600 window system is no exception, as it meets rigorous ICC500-20 and FEMA361-21 requirements based on testing conducted by Underwriters Laboratory. As a result, this system:

  • Can be effectively used within a 250mph wind zone, which makes it ideal for tornado and hurricane-safe rooms.
  • Meets UL752 Level 3 for bullet resistance for added peace of mind.
  • Defends against air exchange, which ensures an energy-efficient building.
  • Features TORGARD30-IG glazing, a system certified for use in storm shelters and safe rooms.
  • Is available with Low E coatings and standard tints.

Along with these specs, STORMDEFEND TTH600 window systems are impressive when it comes to everyday performance.




This window system is designed and certified for use in tornado and hurricane-safe rooms/storm shelters meeting FEMA P361 (2015 and 2021) and ICC 500 (2014 and 2020) standards. It is critical this system be used in conjunction with equivalent performance substrate/wall areas.

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Applications of Hurricane Resistant Windows

In addition to its applications in storm shelters and safe rooms, this window system is also beneficial in many other situations.

They can be effectively used within schools and learning institutions, as well as facilities dedicated to fire, rescue, and law enforcement. They’re also ideal for corporate headquarters, especially those located in storm zones.

Construction Specifications

These windows use extruded aluminum 6061-T6 alloy temper, which provides a tensile strength of 290 megapascals (MPa), as well as a yield strength of 240 MPa. When it comes to interior and exterior glazing gaskets, the use of EPDM sponge rubber ensures optimum water resistance and durability.
Water resistance is improved even further thanks to the specialized weep design, which ensures moisture can efficiently escape from the sill. Additionally, concealed anchors ensure the windows are as aesthetically pleasing as they are robust.


Quality construction is accompanied by numerous features which offer both practical and aesthetic benefits:

  • Customized Finishes: Finishes can be anodized or painted, depending on your preferences.
  • Anchorage Requirements: For your convenience, we provide anchorage requirements that are specific to distinct jobs and projects.
  • Ease of Installation: Windows are shipped fully assembled, meaning they can be installed in buildings immediately upon arrival.
  • Compatibility: These windows are also compatible with standard glazing methods for a more versatile product.


We offer three separate configurations to fully accommodate the needs of our customers:

  • Four-Lite with Horizontal and Vertical Mullion – UL Certification ZHLA.56
  • Ribbon Window with Vertical or Horizontal Mullions – UL Certification ZHLA.55
  • Single Lite – UL Certification ZHLA.52

Please keep in mind that ICC500-20 requirements stipulate that minimum and maximum sizes be tested for each window configuration offered. Feel free to reach out to us to provide specific sizes so that we can confirm they adhere to testing and certification limitations.


Here at Insulgard, we design and construct products that can defend against even the harshest weather conditions. If you’re interested in incorporating STORMDEFEND TTH600 tornado-resistant windows into your building, feel free to request a quote.

We also encourage customers to contact us for more information on our other products and to learn what they can do to increase the safety and security of your building.