How to Install an Egress Window in a Concrete Basement Wall

  • 10-20 hours
  • Advanced
  • 500-1,000
What You'll Need
Masking or Duct tape
Tape Measure
Plastic Liner
Hammer Drill
Long Masonry Bit
Concrete saw
Wood Screws
Concrete Screws

An egress window into a basement can radically improve what would usually be a damp and dark living space, and can also serve as an emergency exit from the room. If you intend to convert your basement into a livable space such as a bedroom or office, then you will need to install an egress window to ensure the safety of users. Cutting into a concrete wall can be a difficult process, but if you have a concrete block basement, and are a keen home improvement fan, you can follow the steps below to complete this project without needing to call a professional.

Step 1 - Make Your Hole

To fit an egress window into your basement, you will need to cut a hole. To do this, measure the size of the window you have purchased, and mark out the space on the wall with duct or masking tape. Before you make any cuts, install temporary supports by fitting some wood joists around 2 feet away from where you will be cutting. Screw this into the masonry studs supporting the first floor. Screw some plastic liner on the far side of the wood.

Once this is done, use a hammer drill and masonry bit long enough to penetrate concrete to drill a line at the bottom of the wall, following the tape. Then take the tape outside, and using this line, recreate the window pattern on the wall you will be cutting through. Use a concrete saw to break through the wall, first on the inside, and then finishing the job on the outside.

Step 2 - Install the Window

Once you have made a suitably level hole, use your concrete to fill the open blocks around the hole. You can also use newspaper in the gaps to keep the concrete from sliding down. Nail wood screws part-way into your windowsill, and then fit it onto the wet concrete. Hammer the nails into the sill is firm.

Next, install the frame, and tap gently into position with the hammer before nailing tightly into the wall.

Step 3 - Finishing Touches

Screw the frame into place using your drill and a masonry bit. Pre-drill for the holes, and then screw tightly using concrete screws. Once the frame is in place, seal around the frame and concrete using an exterior caulk. Use a water resistant variety to keep the water from flooding in.

Once the caulk is dry, install the window glass, caulk around the edges of this frame, and then drive in more screws to keep the window frame in place. At the bottom of the egress window, use mortar to create a water-proof seal, and then leave to dry.