How to Install a Glass Block Window

Lead Image
  • 2-4 hours
  • Intermediate
  • 300-500
What You'll Need
Glass blocks
Measuring tape
Sharp utility knife
Silicone sealer
Plastic tracking
Plastic spacers
Plastic putty knife
Caulking to match the tracking
Wood screws

Glass block windows are ideal for rooms where natural light is desired, but added ventilation is not necessary. They are available in a number of styles and track colors. From glass block patterns that provide privacy to blocks of glass that provide a crystal clear view, you will find a variety of styles to meet your needs, and best of all they are easier to install than many people realize. Many homeowners wanting glass block windows spend a small fortune on professional labor when they could have completed the job themselves.

Instead of hiring a contractor to install a glass block window, consider the following easy instructions and save yourself the expense of professional labor. A glass block window will add style, and the money you save can be used for another remodeling project that will increase the beauty and value of your home. Once you discover how easy it is, installing another glass block window will be a breeze.

Glass Block Window Options

A glass block window is an ideal way to add light to a dark bathroom or foyer, and distorted varieties are an excellent choice for locations where privacy is necessary. When searching for glass blocks you will discover diamond, wave, and various other view-distorting patterns that are as stylish as they are practical. Window treatments will not be necessary, and the glass blocks alone will add design and instant appeal to the room.

If a view to the outside is desired but privacy is still a factor, consider installing four clear glass blocks in the center of the window. Surround the clear glass blocks with distorted varieties. Alternately, install a clear glass block in each corner of the window or around the perimeter for a completely different look that will provide a little privacy with a view.

Step 1 - Measure

Begin by measuring the window opening. Mark and cut the plastic tracking to fit all four sides. A section of tracking one inch larger than the width of a block and half the width of the plastic tracking must be cut away to accommodate the last glass block. Set this piece aside for installation after all of the blocks are in place.

Step 2 - Tracking Installation

Place the tracking in the window opening, and make sure the cutout section is at the top. Mark pilot holes with a pencil to make the job easier. Drill the pilot holes, and attach the tracking with screws.

Step 3 - Installing the Blocks

Now that the tracking is installed, you can begin placing the glass blocks. Position the first glass window block in a bottom corner, and place a trimmed spacer vertically along the side. Position the next block along the bottom, and make sure the channel fits tightly. Continue this process until the entire bottom row of the window opening is filled in.

Top the blocks with a horizontal spacer, and follow the same procedure until reaching the top of the window frame. The last glass window block will go into the area where the tracking was cut out. Apply the silicone to the piece of tracking that was set aside, and securely install the final piece.

Step 4 - Seal the Blocks

Apply silicone sealer to the horizontal seams first. While applying the silicone vertically, skip the horizontal lines, and avoid applying too much. Repeat this process on both sides of the window. Finish by smoothing the material with a plastic putty knife. Have a clean wet rag ready to wipe away any excess silicone. Lastly, seal the perimeter of the tracking and the interior and exterior of the window frame with latex caulk.


Your finished glass block window will provide countless years of use. No matter what style of glass blocks you chose, you will be able to enjoy the natural light. Best of all, you will have saved a considerable amount of money over hiring a professional. You can be proud that you completed the job yourself!