Understanding Impact-Resistant Windows: Large and Small Missile Testing Explained

In the United States, Miami-Dade County sets the benchmark for rigorous code approval requirements for impact-resistant windows, ensuring that they can withstand extreme weather conditions. Central to this approval process, which only the best window manufacturers in Florida surpass, are two main tests conducted: the Missile Test and the Cyclical Test. Understanding these tests is vital for homeowners and builders alike who seek to make informed decisions about impact-resistant products. We explain it in detail here.

The Missile Test

The Missile Test is designed to evaluate the glass’s ability to withstand impact from windborne debris during severe storms. While it is important to note that impact-resistant glass may still break, the goal of this test is to ensure that the window remains intact and stays within its frame upon impact.

• Large Missile Impact Testing: For large missile impact testing, a significant piece of lumber (a 9-pound, 2×4) travels at a speed of 50 feet per second and is launched at the glass twice. This rigorous assessment simulates the force and debris that windows would encounter during a hurricane. Products that pass this test are classified as impact-rated, meaning they have demonstrated their ability to resist hurricane conditions involving large windborne debris.
• Small Missile Impact Testing: Impact-resistant windows from any manufacturer ever the best window manufacturers in Florida must also undergo small missile impact testing. In this test, ten 2-gram steel balls are simultaneously launched at a speed of 89 miles per hour at the glass. The test aims to determine the glass’s resilience against smaller debris that can also pose significant risks during a storm. A model fails the small missile test if any of the steel balls penetrate the glass. It’s important to note that small missile testing becomes necessary under specific conditions, especially pertinent for products installed above 30 feet in elevation, where no protective device is utilized.

The Cyclical Test

Following the missile tests, impact-resistant windows must also undergo the Cyclical Test to evaluate their ability to withstand storm-force winds. This test involves placing the glass in a pressure simulator that flexes the pane under positive and negative pressure for over 4,500 cycles. The results from this test help determine the pressure rating for the impact glass, ensuring that it can endure the intense forces generated by hurricane winds.

Miami-Dade County’s strict testing requirements for large and small missile impacts highlight the importance of using impact-resistant windows in hurricane-prone areas. When investing in glass doors and windows from the best window manufacturers in Florida make sure to ask about these details. At EGS, our high-performance impact-resistant windows are tested for strength, to a 60″ X 120″ module (5×10) and have large missile impact: +/- 100 DP / small missile impact: +/- 130 DP. With the right impact-rated windows, you can significantly reduce the risk of property damage and ensure peace of mind during hurricane season.