Posted by: glassblockblogger | July 29, 2015

Glass Block Assembly: Mortar vs. Silicone

Glass blocks are architecturally like regular bricks. They are both used in the same way only glass blocks can be used in places where traditional bricks can’t. Similarly, these two products are commonly put together in the same fashion; using mortar. However, there are some applications where silicone might be a preferable choice over mortar. This article will delve into glass block assembly using either technique.


When constructing something with glass blocks, mortar is the go-to option. Mortar looks the most traditional and when the product has a chance of being hit by constant water, such as a shower, it’s the one to choose. With silicone, there is a chance water can creep its way in between the joints and loosen up the bond if improperly installed. Mortar withstands all types of weather and holds strong and true for a very long time. You can also makes the joints bigger or smaller to fit the opening better which can’t be done with silicone. There are also many different silicones available to use for glass blocks which can cause much unwanted confusion. There is mortar specifically made for glass block use that is the gold standard in the industry. Glass Block Showr With Style Caps

Another reason to choose mortar over our structural glazing sealant would be if you had to abide by building codes or commercial applications. Most commercial applications need to pass fire codes and mortar will be the only choice in this case. Common applications of glass blocks with mortar are showers, exterior windows, partitions, walls, basement windows and entryways. Glass Block Basement Window


If you want a cleaner look for a glass block application than silicone might be right for you. When using our structural glazing sealant, it requires much less work to put the window, partition or wall together as opposed to the steps needed for mortar. Silicone is used mostly when an all glass look is preferred instead of having visible mortar joints that resemble what you see in tile floors or brick walls. The joints are obviously smaller, less visible and allow more light passing through when compared to a mortar-made product. It is also much easier to apply; you can do it with a caulking gun. Glass Block Basement Window

If the space where the glass blocks are going is small, silicone might be the preferred choice since the joints are smaller which makes the entire product smaller than it would be with mortar. Some people might just prefer silicone over mortar solely on looks without any architectural reasons. Applications such as hurricane and tornado walls made with glass block are constructed with structural glazing sealant. The reason for this is it allows the product to give and take with the high force winds instead of standing without moving. Structural glazing sealant allows the product to “bend” with the strong winds. Glass Block Window

Glass blocks done with either process can be pre-assembled or built on site and both processes can also be assembled with or without a frame. Common applications of glass blocks with silicone are partitions, interior windows or panels, kitchen backsplashes and basement windows.

Has this helped you decide which process is right for you? Let us know! We would be more than happy to help you with a project. If you would like to learn more about mortar vs. silicone, or any glass block products, call us 800-635-1226 or email us at We have over 26 years of experience in the industry and our knowledge attest to that. We look forward to hearing from you!


  1. Reblogged this on JORJ FIN.

  2. What is the easiest way to remove exterior mortar from glass block?

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