How to Install Windows in Concrete Block Houses

Installing windows into a block house does not have to be difficult. Some preparations to the window opening can make the job much easier and leave the window prepared for interior and exterior finishing. Use of a wood buck inside of the concrete opening allows for easier installation of exterior and interior trim and also ensures a square opening for the window installation.

Installing Windows in Concrete Block Houses

Step 1

Cut out the existing window with an electric saw. The window may be screwed or anchored in place or you may have to cut through the nailing flange which secures the window to the outside of the home. Cutting through the nailing flange lets you avoid removing the exterior surface on the house

Step 2

Measure the concrete opening and cut a 2x4 to fit across the lower sill. Use wood shims and a level to make sure this piece is level. Anchor this 2x4 to the concrete with screws or anchors. Follow the same steps for the other 3 sides of the concrete opening. This will give you a wood buck to install the window inside of.

Step 3

Place the vinyl window in the opening. Use shims to create a snug fit of the window in the opening. Do not force the shims too tightly as that may affect the operation of the window.

Step 4

Screw through the vinyl frame of the window to secure the window in place. The windows will have small, vinyl inserts that are removed to access the screwing area and replaced to cover the screw. Ensure that the top, bottom and sides of the window are level. You can use the screws to adjust the window

Step 5

Rip or cut small strips of batt insulation to fill any gas between the window and the studs. Use a shim to stuff the insulation into place. All that is left is to finish the interior with your choice of trim and to seal the exterior with aluminum and caulk