One of the recent industry trends has been the use of silicone instead of mortar for adhering the glass blocks. The silicone used by Quality Glass Block and Window Co. is a specialty silicone that resists water and mildew and is safe for bathroom and window applications and is one of the few silicones available that can hold up under the weight of glass blocks. As an added bonus, the silicone is highly sought after by contracting professionals for its ability to adhere to the industry’s leading glass block vents; Quality Vents.
Using silicone to adhere glass blocks has become a popular trend due to the cleaner “all-glass” look and lighter weight. This method also makes the transportation and packaging of glass blocks much easier and cost effective.
Pouring glass blocks is the “old school” method where glass blocks windows or sections are laid out on a table with ¼ inch joints and while mortar is poured over the glass blocks to adhere the sections together. This is the intended use and how all of the manufacturers have committed their product sizing to. It is that ¼ inch mortar joint that contractors usually do not consider when deciding on whether to use mortar or silicone. By taking away the quarter inch mortar joint and replacing it with a un- measurable silicone joint will affect the overall size of the finished project. Look here for a better understanding of glass block sizes.