Instructions for Installing Glass Block Windows

Installing a glass block window will add beauty and interest to your home. Glass block windows can also add to the security and privacy in a room. For this reason, many people like to use them for basement windows. The molded glass distorts the view so people cannot see inside your house, and the distortion doesn't obstruct sunlight. Instead of installing one glass block at a time, purchase a glass block panel to replace your current basement window. You will need a friend to help you lift the glass block into place because it will be heavy.

Things You'll Need

• Glass block panel
• Wrecking bar
• Circular saw
• Handsaw
• Wood block
• Masonry chisel
• Pointing trowel
• Margin trowel
• Striking tool
• Power drill and screwdriver bits
• Masonry screws
• 3 two-by-four wedges
• Hammer
• Level
• Silicone caulk
• Caulking gun
• Mortar
• Work gloves
• Safety goggles

Instructions

1. Remove the jamb from your window by cutting into the wood sill with a circular saw. This will loosen the sill from the window opening so you that can pry it out. Don't cut all the way through to the concrete or you could ruin your saw.

2. Pry out the sill, the side jambs and the head jamb with a wrecking bar. Bits of mortar will break off the concrete when you remove the sill and jambs; chip off these bits by positioning a chisel on the broken mortar and striking the chisel with a hammer.

3. Screw a wood block underneath the sill plate with a power drill and masonry screws to use as temporary leverage for the glass block panel. Place two two-by-four wedges on either side of the bottom of the window opening.

4. Insert the glass block panel in the opening with the help of a friend. Center it on top of the wedges. Have your friend hold the panel while you position it.

5. Lift up the panel so it is 1/8 to 1/4 inch from the sill plate. Do this by tapping the wedges inward with a hammer.

6. Place a level across the bottom of the panel and level the panel by adjusting and tapping the wedges with the hammer. Insert a third wedge near the center bottom of the panel.

7. Pack mortar into the opening around the panel with a margin and pointing trowel. Work on the bottom first, smoothing the mortar around the wedges. Fill the sides after the mortar on the bottom has hardened. When all of the mortar around the glass block panel has hardened, smooth it with a striking tool.

8. Pull out the wedges with your fingers after waiting about five hours. Fill the remaining gaps with mortar using the trowels and smooth as before with the striking tool.

9. Apply silicone caulk with a caulking gun. Squirt it evenly and thoroughly in the gap between the glass block panel and the sill plate to create a seal. Do this both inside and outside the window.

Tips & Warnings

• Always wear safety goggles and work gloves when using the power drill and saw, and when you are chiseling mortar off the concrete window opening.

References

• Ask the Builder: Glass Block Installation
• Popular Mechanics: Rejuvenate Your Bathroom with a Glass-Block Window