When it comes to window installation in your home, whether they are new construction or replacement windows, there is a right way and many wrong ways. The reason for this post is based our most recent project where we encountered a problem caused by improper window installation. In this particular case the windows were installed over the siding instead of against the plywood sheathing of the home. The potential for problems as a result are numerous ranging from water damage and heat loss.
While heat loss was certainly one issue, an unexpected issue arose as well. While removing the interior trim to replace the window, a fortunately dead bee colony made itself at home between the rough opening and window frame. This is a major issue since the insulation that was once between the rough opening and window frame has been destroyed by the bees and the potential of invading the inside of the home. While this is not a common problem it goes to show you how improper window installation can result in serious damages. If a bee can penetrate to make itself at home inside your home, water and heat can surely penetrate that space too.
The proper way to install a window to prevent water from seeping in and for your home to gain the highest heating or cooling efficiency starts with the windows rough opening. Proper flashing is required to prevent water from seeping in to the framing which can cause rot and mold. As you can see in this picture water has worked its way in the top of these windows and into the Sheetrock causing black mold. Once the rough opening has been properly flashed the window is ready to be installed. The window should be centered and leveled in the opening while sitting tight against the plywood sheathing. Now that the window is in flashing tape is to be applied to the nailing flange of the window. Now that all windows are installed, siding may be applied to the home as recommended by the manufacturer.