Impact-Resistant Windows and PGT Factory Tour

Project: Storm-Ready Design, Episode 4, Part 1

Bob visits PGT Industries to see impact-resistant windows being tested and assembled. Code Compliance Officer Dave Olmstead explains how windows break during a storm, allowing high-force winds to enter the home, pop off the roof, and cause catastrophic building failure. Impact-resistant windows are laminated to stay intact after impact so that wind cannot enter. Olmstead shows Bob the violent impact test used to certify windows to storm standards. He shows Bob windows made of standard annealed glass, tempered safety glass, and impact-resistant glass for comparison. A pneumatic cannon then fires a two by four at each of the windows. Traveling at 50 feet per second, the two-by-four completely breaks the annealed glass, penetrates the tempered glass leaving a hole, and bounces off of the impact-resistant glass leaving it shattered but held together with no holes to invite wind entry. Impact-resistant windows feature two panes of glass with a Buticite layer in between. The glass is pressure baked at 450 degrees for four hours before it can be set in the heavy-gauge frame with silicone adhesive. Bob watches the assembly process and learns that sales of these impact-resistant windows have risen 300 percent in the year since Hurricane Charley.
Part 1: Impact-Resistant Windows and PGT Factory Tour
Bob is at PGT Industries in Venice, Florida, for a visit with Dave Olmstead, the code compliance officer for PGT Industries, makers of impact-resistant windows. Olmstead explains how windows are a fundamental element in storm-ready buildings because they keep the envelope closed to damaging wind entry. If wind enters a home during a high wind event, it increases the pressure inside like air in a balloon. The air has to find a way out and typically pops off the roof, causing catastrophic building failure. Olmstead then shows Bob the impact resistance test that is performed on windows to determine the level of protection they offer and whether they perform up to code. The first window is made of regular annealed glass. It is not tempered, heated, or coated in any way. The second window is made of tempered safety glass. The third is of impact-resistant, laminated glass. Olmstead runs the cannon test, where a two by four is fired from a pneumatic cannon at 50 feet per second or 34 miles per hour, simulating the force of 110 mile per hour winds. The annealed glass breaks and falls from the frame. The tempered glass shatters within the frame but leaves a hole where the board entered, allowing wind to penetrate the structure. The laminated glass shatters but is held in place. It does not perforate so the home is protected from wind entry. Impact-resistant window glass is safety laminated on site at PGT. They cut glass to the appropriate size, cutting two panes, then cut butacite to fit between them. The glass sandwich is then baked with the laminate between in a heat and pressure oven for four hours. Once it is cooled, it is ready to be assembled into a window.
Part 2: Finishing the Impact-Resistant Windows
Part 3: Building Reinforced Concrete Storm-Ready Homes in Florida