How our windows are tested

The video begins with infiltration testing that’s meant to simulate a worst-case scenario in which 8 inches of rain are falling per hour and wind is gusting at 55 mph. By forcefully spraying water at the window while also applying negative pressure to the backside, the test seeks to identify any leaks within the window unit itself — the sill, jamb liners, head jamb, etc. It is not a test of the installation, though our recommended flashing details are tested separately.

Schiffer demonstrates spraying red clothing dye at the window. The dye can be used to identify where a leak is occurring if infiltration is happening but its location is unclear. After the test concludes, Grace examines the window with a flashlight to look for leakage, paying special attention to what are typically the weakest points on any window — the corners. They discuss the continuous weatherstripping used on our windows to help prevent leakage at the corners and overall. Grace finds no water intrusion. The window shown passes the test, which comes with a high standard: Not a single drop of water should reach the interior-most frame.

The two also explain what happens when a window doesn’t pass the test. It gets sent back to engineering with the testing results. The window is then redesigned before once again undergoing testing. By testing to failure or for a period of time without failure, no matter how many times it is tested, we go beyond industry standards.

Schiffer and Grace then move on to discuss structural testing, focusing on air loads applied to doors. Structural testing is performed to look for deformed sashes, cracks, stiles, and other trauma that could occur when a product is put under pressure. The builders explain how both positive (outside in) and negative (inside out) pressure scenarios are simulated. A positive pressure test is then performed on an 8-foot gliding patio door simulating winds of 145 mph by applying 3,400 pounds of force against the door. Schiffer holds a 2x4 piece of wood against the center stile to show the deflection, which is about 1 ½ inches when the maximum pressure is applied. As the center of the door and furthest away from the support provided by the rough opening, the center stile is the weakest point. The stile must withstand this pressure for the door’s structural integrity to remain intact. Once the vacuum pressure is removed, the center stile returns to normal position for a successful test. Passing the test requires that the door still operates and returns to within 4% of its original shape.

Moving on to impact testing, Grace and Schiffer explain how an impact cannon is used in coastal product performance testing. The impact cannon is loaded with a 9-pound 2x4 that gets launched at a window at the rate of 34 mph to simulate a scenario in which there is high wind causing flying debris to hit the window. They then launch the cannon at a 5-foot-by-10-foot coastal window made with monolithic laminated glass — two panes with a clear laminate material sandwiched in between. They launch the cannon multiple times at specific areas of the unit. The outer pane of glass eventually breaks in two places, but the window remains intact — the inner pane of glass must not be breached for the test to be passed. After the impact testing, the window is then put under roughly 4,000 pounds of pressure to simulate the effect of wind blowing at 180 mph. Similar to the door test, a straight edge is held against the window to demonstrate the deflection that occurs. Despite the pressure, the window remains intact.

Our coastal windows — those with Stormwatch® protection — must pass the standard air, water, and structural testing (Performance Grade testing) that all our windows are subjected to as well as impact testing. These products are designed, engineered, and manufactured to satisfy: ASTM/E1886/E1996 large missile test, TAS 201, 202, 203 large missile test for High Velocity Hurricane Zone, and AAMA/WDMA/CSA 101/I.S.2 A440-11.

Grace and Schiffer are the voices behind the Modern Craftsman, which is a podcast and community network dedicated to promoting excellence, education, knowledge, and respect in the building industry. With their audience of trade professionals, they discuss all aspects of life within the industry and life itself — from mental health to leadership and everything in between. They pride themselves on working with brands and people who strive to make the industry better and advocate for a better life in the trades.