What are the Best Tips for Glass Block Installation?

Glass blocks are used as architectural elements, windows or room partitions, and are a favorite of homeowners because they let light in from the outside or an adjoining room. Installing glass blocks is a relatively easy process because it does not require a lot of expertise or tools to complete. For the do-it-yourselfer, there are tips to follow such as measuring and planning carefully, setting the panels properly and caulking where necessary.

The first best tip for glass block installation is to measure the area being filled in with glass blocks very carefully. Do-it-yourself home remodeling and project experts suggest that measuring the area twice to be sure to get the same measurements both times. If there is an existing window frame where the glass blocks will be installed, start measuring from where the frame will be removed rather than the frame itself.

Use cedar shims to set the glass panels and plan for the layout prior to completely the glass block installation. The shims keep the glass blocks off the perimeter of the installation area so it can be cemented and caulked in the appropriate places to hold the blocks in place and seal it from water and other elements. Place shims about three inches (7.62 cm) from the bottom corners of the area and about a half an inch (1.27 cm) from the top of the opening where the glass block installation will go.

Portland cement and sand mixture is the best type of mortar to use for glass block installation. Avoid using bricklayer’s mortar because it is not as durable and waterproof as Portland cement and a sand mixture is. To apply the mixture to the open area, use a trowel to gather and spread the mixture on the edge where the glass block installation will occur. Do not apply the mixture to the top of the area. Pull out the cedar shims about two hours after the area is cemented.

Apply caulk to the top of the window area where the glass block is installed. Wait for at least 24 hours after installation and cement the glass block to caulk the top. This allows for the cement to dry completely. Use 100 percent silicone caulk and caulk within a half an inch (1.27 cm) from the top of the area down toward the glass blocks where the joint ends.