How to Install an Egress Window

This is part 4 of a 4-part egress installation series.

Part 1: How to install an egress window well.

Part 2: How to complete a concrete cut for an egress window.

Part 3: How to frame an egress window.


So you are thinking about installing an egress window yourself. Now you just need to know how to install an egress window! Completing this DIY-style may not qualify as a basic project, but it can be a very rewarding and money saving experience.  

The following 11 steps will walk you through what is required so you can learn how to install an egress window.


1    Test fit the egress window into the opening.

To do this, rest the window on the sill, align it squarely with the opening, and then tip it forward into place. Also consider the walls and ceiling around the opening. If the window opening is flush with the ceiling or an adjacent wall it may prohibit the window hardware from engaging and prevent the window from being fully opened. Don’t forget to allocate enough space for a hand holding the handle as well.


2    Install shims on the sill.

Install Shims along the egress window

Shims should be positioned near the edges and in the centre of the where the window will sit. The exact locations will depend on the operation and size of the window, but they should be no more than 16” apart along the sill. Dabbing sealant under the shims can help keep them in place when setting the window but keeps them loose enough so they can be adjusted as needed later.


3    Set the window.

Close the sash and lock it into place to prevent it from moving. Set the bottom edge of the window on top of the shimmed sill at the bottom of the frame, with the top of the window leaning out at you. Carefully push the top of the window into the frame.


4    Shim along the sides.

Insert shims between the side jambs and side of the frame. While the exact location of the shims depends on the size and operation of the window, they should be no more than 24” apart on the sides. If you are using tapered wood shims, always use them in pairs, one from the inside and one from the outside to ensure that the frame is evenly contacted along all frame depths.


Shim Location for an Egress Window

5    Ensure window is square.

Measure the distance across the window diagonally in both directions. If the window is square, the measurements will match. If they do not, adjust the shims until they do. If the window is not square it may cause too tight of a fit and prevent the window from being opened freely later.


Ensure Egress Window is Square

6    Fasten window to frame.

The exact location of the screws will depend on the type of window being installed as well as the type of wall and frame being used.

  1. If installing in a concrete block wall: Once the window is square and plumb, fasten it into the wood frame with galvanized or stainless-steel screws driven through the shims. To prevent cracking of the vinyl frame and shims, we recommend drilling pilot holes through the vinyl window frame and shims.
  2. If installing into poured Concrete Wall - Drive concrete anchors through the tapered shims. Pilot holes should be predrilled through the vinyl window frame, shims, and into the Poured Concrete Wall to prevent cracking of the vinyl frame and shims. This will also help to facilitate the installation of the Concrete Anchors.


Egress window with installation clip attached
Egress Window with installation clip attached

7    Ensure the window operates properly.

Open and close the window to ensure that it can be done easily. Check to make sure that the window can open fully as this will be required to meet egress code.


8    Foam the window.

Apply a bead of low-expanding foam in the gap along the top and sides of the window. Do not over do it. Just dispense enough foam to create a 1” or 1 ½” bead that bridges the entire gap between the window and the framing. Run the bead out a little way along each side of the shim. Do not fill in the whole space. Even low-expanding foam can expand enough to distort the jambs.


Foam the Egress Window

9    Add insulation.

Fill in the rest of the gap on the sides (above the lower shims) and the top with fiberglass or rock wool insulation. Fill the whole gap but keep it loose and fluffy. Insulation loses its effectiveness the more tightly packed it gets.


10    Caulk window.

Apply a generous bead of caulk around the treated wood frame to create a seal for the basement window.


11    Trim the window inside and out as required.

There are many different ways that you can trim a window and most of them come down to a matter of personal style and preference. Trimming an egress window is no different from trimming any other window and there are many resources out there that describe the process very well, like this post from Family Handyman.  


Trim Egress Windows


 There you have it, you now know how to install an egress window. If you followed along, you should an egress window in your home and ready for you to enjoy. It may not be the simplest DIY project, but with a little bit of work you can save yourself a few hundred, if not thousand, dollars. 



If you are still looking to get the actual egress window for your project, the Great Egress Co. may be able to help. We stock and sell egress windows in a variety of sizes and styles. Plus, we will ship it straight to your door at no extra cost. Check out our collection to see how we may be able to help you. 

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