How to Replace Your Basement Windows

Basement windows are often small and so they can easily be neglected. However, this doesn’t stop them from being the frontline barrier to keeping your home warm and protected against the outdoor conditions.

This makes it very important to make sure your windows are in perfect shape and should an issue become apparent, be quickly replaced. We have prepared this simple guide to show you which steps are necessary to take to install a new window in your basement.

Most basement windows come with two types of frames; wood and steel. While wood offers the advantages of beautiful architectural detail, solid thermal performance, and a wide variety of colour choices, this material comes with significant exterior maintenance and at a high cost. Steel, on the other hand, offers great strength and overall durability but at the cost of feeling cold and giving a somewhat commercial look to your windows. Remember, wood frames are secured in the concrete while steel frames use a buck embedded in the concrete (meaning it will require more force to remove).

The replacement of your basement windows

Photo: Max Pixel

What to prepare

The first major step with any job is making sure you have the proper safety equipment and tools. For this job, you will need the safety basics of gloves, goggles and a face mask. For tools, you’ll need a hammer, a reciprocating saw, screws and screwdriver, some shims, caulking, some urethane sealing foam and some exterior-grade primer.

The tools you will need to replace a basement window

Of course, you can’t move forward without taking the proper measurements of your window. Keep in mind that measuring the frame from the inside will give you the most accurate numbers. If you’re dealing with a metal frame, remember to account for the buck when measuring. Depending on its state you may need to remove and replace the buck, usually when heavily rusted. Otherwise, if it’s in good shape it may be easier to leave it in place. Lastly, for the most accurate measurements, we always suggest checking both width and height in at least two places, using the smallest dimensions.

Steps to replace the basement window

Photo: Pexels

Now you can begin prepping the work area and this starts by removing the sash from the basement window. Once the sash has been removed and discarded, it’s time to cut through the window frame. At this point, you should have your reciprocating saw handy to slice deep into a wood frame. You can use the saw on metal frames but use extreme caution as it is likely that sparks will fly.  At this point, the frame should be loose enough to remove it completely from the opening in the wall. To make sure your new window will fit flush into the opening, you may need to use a hammer to gently chip away excess mortar from the sides that could affect the snug fit.  

Now that all the preparation has been taken care of, it’s time to install the new window. First, slide it into the wall opening to ensure that it is the right fit. Although you may need to push the window into place, try not to force it into place with too much strength or you could risk breaking the glass pane. Now that it is in place, you need to use the shims (thin pieces of wood wedged between the frame and the opening) that will help keep the window centred within the opening.

By this point, the window is ready to be secured in place by screwing through the frame into the sill. Now all that remains is to securely seal the window along its seams. Using the caulk, run it along the sides and top of the frame to fill in the gaps and create a solid barrier. Now, use the urethane foam, sprayed under the sill to seal the bottom of the window. Make sure to do this both inside and outside.

If you are replacing a wood window, the final step will be to apply a coat of exterior grade primer to any exposed wood. Once the primer dries, the wood will be better protected against rain and should you wish to paint, it will be ready to go!

Remember that if you’ve replaced the window once, then you should not have to think about it for many years to come. With that said, this is a preliminary guide to basic window replacement for the basement.  Your job may require more attention because of the masonry and other factors, so we thoroughly suggest consulting an expert in order to have your windows seamlessly installed.

Are you currently organizing a basement renovation project? We've prepared a highly practical checklist to help you manage the different steps involved in this project. Click here to check it out and be sure to keep it handy  

Author: David Ben-Zaken