Framing a window in a brick wall is of a relatively simple, three-step process. The process starts with preparing the building site and outlining the window then continues with cutting into the brick and installing the window framing elements. You need some heavy-duty and potentially dangerous tools for this job, and it will require some hard labor. Always exercise caution when working with power tools, such as circular saws and hammer drills.
Things You'll Need
Chalk or tape
Circular saw with diamond-tipped blade
Masonry drill bit
Determine the size of the window you want to frame in the brick wall. Base the dimensions of the window frame on a window you plan on purchasing for installation or the egress requirements under local building codes for installing a basement or bedroom window.
Mark a line on the wall to indicate the top of the window frame in chalk or a piece of tape. "This Old House" magazine notes that the tops of most windows sit 80 inches from the floor so the middle of the window sits at an ideal height for viewing. Measure down from the top of the wall to locate and mark this point.
Use a tape measure and chalk to mark the outline of the window on the brick wall with the dimensions and top line of the window noted in Step 2. You must install the window framing against solid bricks, rather than mortar. Arrange the outline of the window so that when you cut away a portion of the wall, you expose flat brick surfaces on the sides, top and bottom.
Locate the bottom center point of the window by measuring to the midpoint of the bottom line drawn on the wall for the window frame.
Put on work gloves and safety glasses.
Drill a hole all the way through the wall at the bottom midpoint using a masonry drill bit. Use a hammer drill if a standard drill lacks the strength to bore through the wall.
Go outside and draw an outline of the window on the outside of the wall, using the hole in the wall as the bottom midpoint.
Removing the Brick
Lay tarps on the floor of the room and the ground beneath the brick wall. Clear all furniture away from the wall.
Cut along the outline of the window frame on the inside of the wall with a circular saw equipped with a diamond-tipped blade.
Use the saw to cut along the outline of the window frame on the outside wall.
Hit the bricks out of the window frame area with a 4-pound mallet. The cuts made with the circular saw should make the bricks loose enough to dislodge without power tools.
Remove any sharp edges or protrusions from the walls of the cutout area for the frame with a brick chisel and mallet. Hold the chisel against the protrusions and hit the handle with the mallet until they come loose.
Measure the inside top and bottom lengths of the frame.
Cut one 2-by-4 to the length of the bottom of the window opening with a circular saw. Cut the header to the length of the top of the opening with the circular saw.
Place the 2-by-4 cut to the length of the bottom of the opening on the exposed brick at the bottom of the frame. Attach the wood to the brick with a drill equipped with a masonry drill bit and masonry screws.
Hold the header in place at the top of the frame and measure the distance between the header and the piece of wood at the bottom of the frame.
Cut two 2-by-4s to the length measured between the header and bottom piece of wood. Mount these 2-by-4s so they fit snugly against the sides of the window frame, between the bottom and top.
Place the header on top of the 2-by-4 side frames. Gently tap the side pieces of wood against the walls with a mallet if they shift when you move the header into place.
Mount the side and bottom pieces of wood to the brick around them with masonry screws. Space the screws at even intervals across the length of the boards, no more than 12 inches from one another.
Attach the header to the walls by driving masonry screws through the ends of the header and into the brick around it. If you're installing a header just below the joists for the floor above, screw the header to the joists as well.
Apply exterior-grade caulking approved for use with wood and masonry materials where the bricks meet the window frame on the inside and outside of the wall.
Install the window in the frame area per the instructions provided by the window manufacturer.
If you don't have the right tools for this process, such as a diamond-tipped saw blade or a hammer drill, you can rent them from a building supply or hardware store.
When cutting into a wall that carries a load, you must add temporary structural support for that wall in the form of a brace. Look for resources on building temporary support braces in magazines, such as “Family Handyman” or “This Old House,” at your local library. Consult a structural engineer before cutting into a load-bearing wall.