How to Install Glass Block Windows in Steel Cased Basement Windows

Open the windows and look for the pin assemblies holding the windows in place. The pin assemblies look similar to hinges on the sides of the windows. Cut the assemblies off with a reciprocating saw. Cut off any metal pieces you see.

Unscrew the small screws on the crank assembly, which is the piece you use to open and close the windows. Look for the metal studs near the bottom of the window and cut those off with the saw. Remove the windows and pull the metal studs from the frame with pliers.

Pour powdered mortar and water into a plastic bucket, using the ratio specified by the manufacturer. Add 1/4 the amount of water needed and mix. Slowly incorporate the rest of the water, until the mixture resembles thick peanut butter.

Apply a layer of mortar on the window frame approximately 1/2-inch thick. Apply a layer of mortar to the sides of one glass block and set it into the window frame. Push the block over until it sits flush with the frame. Add more mortar to the side of a second block and press beside the first block. Keep adding glass blocks until the blocks cover the bottom of the window.

Cover the top of the glass blocks with a second 1/2-inch layer of mortar. Press more glass blocks on top, adding mortar to the sides of each block. Continue stacking the blocks until the glass completely covers the original window.

Let the mortar dry for a minimum of 24 hours. Examine the window carefully, looking for any gaps between the glass blocks or the blocks and the window frame. Fill in the gaps with clear caulk and let dry overnight. The caulk expands and fills in the gaps, blocking warm and cold air.