How Do You Install a Casement Window?

Casement WindowInstalling casement windows in your home can add to resale value, overall beauty, and energy efficiency, but you may be at a loss as to how you can do this. Here, we’ll go over the process, the tools and materials you’ll need, and other considerations to keep in mind when performing this type of home improvement project. The great news is that yes, you can do this yourself and do so on a relatively modest budget.

Prepping the Window Aperture

Of course, this doesn’t cover cutting window apertures in the walls of your home, but merely the installation of casement windows in existing apertures. However, we’ll go through every step of the process below. If you have an existing window in place, make sure to remove it and ready your window aperture for a new casement window. If you have siding, clapboard, or shingles around the window, cut these away without cutting into the frame just around the aperture using a circular saw. Brick or brick façade will require you to remove the bricks to allow room for placing the new window and can be put back after you install the casement window. You’ll need between one and two inches of clear margin around the opening to allow you to set the new window.

If the existing space is too large for the new window, narrow it by placing plywood flush against the framing and nailing it in place with galvanized nails. Most experts use 3/8 inch plywood cut to the appropriate width, but you should assess the needs of your particular window and use thicker plywood as needed. Before you set your window, also be sure to tuck aluminum tape under the facing material at the top of the aperture and apply metal tape along the bottom. This will help to ensure that no leaks or drafts can find their way in around your casement window, according to the San Francisco Gate.

Finally, using a level, ensure that the bottom of the aperture is completely flat. If needed, place shims to create a stable, perfectly even base for the window. These can be made from plywood and sheet metal to meet your exact needs. Simply cut them to fit the depth of the opening, place metal-side up, and tack into place.

Setting the New Window

Most manufactured casement windows will come with a nailing flange, which is a pliable metal skirt around the window that you’ll have to shape by hand so it forms a 90 degree angle to the window frame. When you slide the window into the aperture, put two nails into the top flange to hold it in place. Then, check the level and plumb lines of the window on the inside to make sure they are perfect. Place some temporary shims between the frame and the inside of your window opening.

Once you’ve done that, finish nailing the flange in place. Cover the nailing flange with some adhesive backed metal tape will help to create a tight seal against weather. Then, install wood trim on the sides and top of the window opening to conceal the tape. A drip cap should be a part of the top trim piece to ensure no moisture gets into the wall. A bottom sill, if any, should have a sloped surface to cary moisture away from the new window. You can purchase these pieces, or, if you feel confident in your woodworking skills, make them yourself. Lastly, prime and paint the frame to match your home’s exterior.

Finally, on the inside, pack the gap between the window and the wall with insulation to maintain the r-value of your home and block any loss of energy. Then, you can place pre-cut, pre-primed trim and an inside, bottom windowsill to finish the project. These can be cut at the hardware store for you, with mitered edges for a lovely finishing touch. If you elect to do this yourself, simply cut the edges at an angle so they will sit flush against one another and nail them in place. Then, paint it to match your design scheme. All that remains is to install hardware of your choice, such as window locks or handles.

Related Resource: How To Install French Doors

When it comes to home renovation projects, window installation is actually surprisingly easy. All it takes is a bit of patience and the proper tools and materials. While some projects will require professional assistance, the excellent news is that you can install a casement window on your own. Just be sure to enlist a bit of help with the actual installation, to avoid dropping your new window before it’s put in place. It’s actually surprisingly simple to install one or several casement windows to update the look of your home, improve energy efficiency, or even as a replacement for drafty, existing casement windows.