Luckily, glass block windows need minimal maintenance. Other than regular cleaning, the only maintenance involved in having a glass block window is inspecting for cracks every year and applying sealer to the mortar joints if the blocks are set in masonry mortar. Glass block windows hold up well against wind and moisture better than traditional windows and are not prone to rot.

Although glass block windows are made of multiple layers of thick glass, they can still break. If an individual block shatters, it can be removed and replaced, but this is a job for a window repair professional. The project is often complex and may require breaking the block further for removal. Do not attempt to handle it yourself, as the broken glass can be dangerously sharp. A professional will have the necessary tools and expertise to replace the broken glass block quickly and safely. Before hiring, confirm that the repair pro has experience with this specific type of window.

Glass block mortar is the best choice for glass block window units. It is specifically formulated for glass block window installation. Glass block mortar is usually a mixture of Portland cement, sand, and special chemicals. It is a white mortar that is applicable inside and outside your home. Do not use regular tile mortar because it may not have the binding strength and flexibility required for glass block windows.

Glass block windows aren’t fire hazards; fire-rated glass block windows can increase your home’s fire safety. Modern glass blocks are made with materials that can resist high temperatures and prevent fire spread. Most offer a 45-minute fire rating, while some increase it to two hours. Compared to the typical 20 to 90 minute rating for a double-pane window, glass block can increase your home’s safety in the event of a fire.