How To Install Basement Windows

Long Custom Windows

Installing basement windows can give light to an otherwise dark area. In this way, the space in the basement can be used more efficiently. Window kits are available, which have frame and windows already mounted, as well as the necessary mounting and installation of hardware. In applying this article, we will assume that the openings for cellar windows already exist. Therefore, the steps will cover only the installation window.


Measure existing window opening so you know what size window kit to buy. Measure carefully so that you can match the basement in windows kit size as close as possible to the opening. Record your measurements. Buy the window kit (s) you need, in the sizes you need. If it is needed, does any work required to ensure that the windows you purchased fit the opening. This may mean extending the opening slightly. Whether you need to make any adjustments, clean and smooth the opening so that the window will fit as tightly as possible.

Install a piece of casting on the inside of the basement windows. This can be included in the kit, or you may need to build one from either wood or metal. Work from the outside, mount the frame for casting, and secure it only enough so that it will stay in place. Mix mortar, according to the supplied directions, so it is thick enough and stops where it is to be used. Apply it to the bottom and sides of the window. Put material that will allow expansion to the top of the window and seal all the way over the top of the window.