Assembly Material

Glass Block Windows can be assembled out of two materials. One being mortar/cement and the other being silicone. Each material has its benefits and drawbacks.

Silicon joints sample 1

Using mortar was the most common form of assembling glass blocks windows for decades. It was the most efficient and secure way. Mortar joints are usually white and provide a checkerboard look to the window. That being said, many times the joints are offset white, and sometimes colored to match the color of the building the glass block windows would be installed in. Mortar joints were also widely believed to be the most durable way of making glass block windows, when in fact the joints tend to dry out and crumble over time. Over the years more people noticed these issues and decided to use a new material to assemble glass block windows.

Silicon joints sample 2

In the last 20 or so years, using silicone, or caulk, in the assembly of glass block windows hasbecome extremely popular. Silicone joints provide all the security, strength, and durability that cement windows do, while offering a cleaner look and almost no drawbacks. With a clear silicone joint, the glass block window allows more light to come through and makes the glass block window look just like a regular window would, with no dividing lines. With silicone joints, glass blocks are flush against one another, allowing no room for air to seep through, making them more energy efficient. The glass blocks being close together also provide strength to the whole window. Where with cement joints, a broken glass block might compromise the integrity of the whole window, with silicone there is no issue. A silicone joint will not crack like a cement joint might. Silicone joints for assembly of glass block windows are also preferred for bathrooms because a silicone joint will not allow mold or mildew to grow, which often happens with the moist air in bathrooms. In the case some mold might grow, a simple wipe off with a sponge usually cleans it. Since manufacturers decided to use silicone joints for glass block windowassembly, many more homeowners and commercial building owners have looked into getting glass block windows installed in their buildings.

Cements joints sample 1

We at the Glass Block Factory offer the choice of both silicone and cement joints, as well as a variety of glass block patterns and glass block vents.  Feel free to visit our website at to see samples of both.

Vented or Solid Glass Block Window

Aside from choosing an assembly material, many people struggle in their decision over having a glass block window made with a vent, or leaving the window solid glass block. Each option again has its benefits and drawbacks. In most cases glass block windows have a vent. This allows for air flow which most homes need. Bathrooms, basements, and bedrooms almost always have vented glass block windows. Bathroom glass block windows need the vent to eliminate moisture and prevent mildew buildup. Basement glass block windows need the vent to allow air to circulate, again eliminating moisture and any smells. Bedroom glass block windows need the vent to make sure there is plenty of fresh air to make sleeping as comfortable as possible. Everyone enjoys a good night’s sleep. Solid glass block windows are most often used in commercial buildings or basements where the windows are in window wells. In many commercial buildings windows are hard to access and vents are unnecessary. Some business owners also prefer the security of a solid glass block window. A solid glass block window would be preferred in a home where window wells fill up with water during storms. Even though glass block vents are waterproof, when window wells fill up, water can sometimes seep through. A solid glass block window does not allow any water to get inside.

Cements joints sample 2

As with any other window or home remodeling decision, it comes down to personal preference. Many people have their own opinions about vented glass block windows and solid glass block windows. Glass block factory offers both options as well as a variety of glass block patterns and glass block vents.

Feel free to visit our gallery and check out some sample pictures.