Building Reinforced Concrete Storm-Ready Homes in Florida

Project: Storm-Ready Design, Episode 4, Part 3

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
Part 2: Finishing the Impact-Resistant Windows
Part 3: Building Reinforced Concrete Storm-Ready Homes in Florida
Aaron Renfroe from Great Southern Windows installs the PGT WinGuard windows as Bob looks on. He first applies a thick bead of polyurethane caulk to the flange on the window frame. Bob points out the cast concrete lip on the window buck that will provide a solid surface behind the frame to prevent blow-ins. The caulked edge of the frames lays up against the concrete lip to make a very tight seal. These heavy windows are held in place with long masonry screws, called Tap Cons. Since Hurricane Andrew, stringent codes have required longer screws that are drilled right into the block or concrete.