Making sure your windows are waterproof before installation is a critical step in the building process. In this video, Matt Risinger, master builder demonstrates how to perform a simple test to ensure that they are leak free.Testing inexpensive vinyl windows is easy and, when estimates are that 20% of them leak before installation, it's an important exercise. Risinger chose an off-the-shelf vinyl window and admits that he chose one that might have a problem. Vinyl windows have a heat seam in the corner, so there's a hot plate and then they push this miter together and then the squeezed-out vinyl gets trimmed. If that trimming machine is off by a few thousands, we might have a problem. This window is molded down the center and hardware is screwed into that.For the test, working from the exterior of the window, every window will have weep holes, which for the test will be covered with duct tape. Using water with food coloring, pour the water in the sill as if water is trickling down the face of the glass and ending up into the pan. When it begins to fill, the water will come out of the weep holes, but the duct tape will stop it from coming out. Window manufacturers must adhere to a test that states that the window must be leak proof for 10 minutes. Fill the pan as high as you can. Before the pan is full, there's already a leak. Coming back 10 minutes later, it's clear that the leak started at the mold transition in the center. Takeaways…the better the window, the less chance this will happen. Put windows in a waterproof opening, use a sill pan underneath, using a fluid applied or peel-and-stick product, run it all the way in on rough openings. Ready to test some windows?