How to install glass blocks

Instructions how to install glass blocks in 9 easy steps. Download the pdf for a step by step guide of your project.

Glass Blocks

A glass block wall or window subtly defines both indoor and outdoor living areas while allowing light to freely illuminate the areas. They are strong, safe, easy to clean and practically maintenance free.

Step 1:

Lay the glass blocks in a dry run. Cut some spacers into Land T-shapes for the corners and bottom/top rows respectively, in addition to the X shaped spacers. Begin by placing a spacer against the existing wall, place the first glass block into position, and add a spacer. Mark the position of the blocks on the existing wall and along the floor and remove the blocks.

Step 2:

Mix only enough glass block mortar to be used within 30 minutes to avoid waste. Lay about a 3/8 inch (approx.1 cm) thickness of mortar for the first four or five blocks. Do not place mortar between the glass blocks and the expansion strips on the existing wall. Set the first glass block on the mortared elevation up against the expansion strip. Place ¼ inch (approx. 6 mm) T-strips at the mortar joint locations: for the first block, place a T-strip at the top corner of the block that touches the expansion strip on the existing wall and on the bottom corner of the block that faces out toward the next block in the course.

Step 3:

Install the spacers between the glass blocks to fix them in place. Continue to install the glass blocks layer by layer with the glass block mortar and spacers. Use a level to check each block to ensure a straight line.

Step 4:

Lay a ¼ inch (approx. 6 mm) thick bed of mortar on top of the first row of blocks. Lay the second row of blocks in the same manner as the first. Check each block with the level and adjust the blocks with the mallet as needed.

Step 5:

Lay a1/8 inch (approx. 3 mm) thick layer of mortar onto the top of the second row of blocks. Cover with approximately 1/8 inch (approx. 3mm) thick mortar. Repeat this procedure.

Step 6:

Lay the third row of blocks in the same manner as the first and second rows. Check each block with the level and adjust the blocks with the mallet as needed. Continue laying blocks in rows until you reach your desired wall height. You can use tile strips or corner blocks to finish the edges.

Step 7:

Twist off the spacer tabs, if applicable, when the mortar has dried for approximately 30 minutes. When finished, fill the joints between the blocks with additional mortar.

Step 8:

Press in the mortar joints with a jointing tool and smooth out the seams. Remove excess mortar with a wet sponge or natural bristle brush.

Step 9:

Allow the mortar to dry for two weeks, then apply a sealant to the grout lines.