How to Make a Glass Block Window

Glass blocks are often used to create visual privacy, yet allow the flow of light. They also contribute to the decor of the room in which they are used. Glass blocks were first created in the 1900s and are back in style. Making a glass block window is similar to laying cement blocks.

Instructions

Make a Glass Block Window

1. Measure the size of the opening where your glass block window will go. Proper measurement is essential in order to purchase the appropriate number of blocks and make proper allowance for the mortar, expansion foam and the trim around the window.

2. Secure your measurement and cut 2 x 4 pieces to the sides of the window opening.

3. Prime the bottom sill in order to prevent moisture from the mortar from seeping into the wood.

4. Place a layer of mortar on the sill. Set spacers into the grout, then begin to place your blocks on the mortar. Press the block into the mortar. Be sure to leave a little space between the first and last block and the window trim.

5. Put some mortar on one side of the next block and set this side next to the previous block.

6. Use the expansion foam after the first layer of blocks is complete. Put some of the foam into the space between the first and last blocks and the trim.

7. Repeat the previous steps until the open space is filled. You may need help with installing the last row of blocks due to the limited space. Use the expansion foam up the sides and on top of the last row of blocks.

8. Break off the spacers when you are done.

9. Use glass block sealant caulk to prime the area around the window, on both the exterior and interior sides.

10. Learn more about installing windows by reading "The Complete Guide to Doors & Windows" by Tom Lemmer.

Tips & Warnings

• Ask a friend to help. Although the job can be done alone, a second person can help ensure that the glass blocks are set evenly.

• Never use glass blocks to build a load-bearing wall.