How to Install a Window in Brick

Measure the window's rough opening in the brick wall. Double check the dimensions will work with the new window by measuring the window's frame. If you need to make the opening smaller, cut a 1-by-4-inch pine board to either the length or width, depending on which dimension you need to make smaller using a circular saw. Nail the board in place with 1 1/2-inch nails.

Lay the new window face down on a flat work surface. Bend the nailing flange, the piece of metal that goes around the window's perimeter, out so it forms a 90-degree angle to the window's frame.

Put a tube of silicone caulk into a caulk gun. Cut off the caulk tube's tip with a utility knife and apply a bead along the nailing flange, all the way around the window.

Lift the new window into the rough opening from the outside and center it. Push it in until the nailing flange rests firmly against the wooden frame inside the brick wall.

Go inside and lay a level on the window's bottom edge. Insert wooden shims between the window and rough opening to lift up any low areas and level the window. Hold a level against one of the window's sides and adjust the window so it is plumb in the opening. Insert wooden shims along the window's sides to keep it in place.

Return outside and hammer nails through the holes in the window's nailing flange through to the wood frame. Squeeze a generous bead of caulk into the gaps between the window and the brick wall on either side of the window.

Fill any gaps remaining alongside the ripped boards with expanding foam. Return inside and score each wooden shim where it extends past the window frame with a utility knife. Bend the shims so they break along the score line. Add trim to the window on the interior of the house to finish the window.