Frequently Asked Questions

There's no need to remain in the dark about how to start living with light!

Q. What is the exact size of a glass block window?
A. REDI2SET windows can be made to fit any size window opening. See our BUILD section for details on how to measure.

Q. What is the thickness of the block?
A. Glass blocks come in 2”, 3” and 4” nominal thickness because different products and applications require different thickness. CrystaLok windows have an adjustable frame and can use all three sizes, but 2” is the lightest and easiest to install in large windows. REDI2SET windows use 3” block because they come in the most number of face sizes giving REDI2SET windows greater flexibility to fit into existing openings. Showers and partition walls are normally built with 4” because of its greater stability.

Q. What kind of mortar is needed to install?
A. Premixed glass block mortar is the most convenient and provides the most consistent results, but you may follow the formula for type “S” mortar and mix your own.

Q. How do you put the window in?
A. REDI2SET and CrystaLok windows are surprisingly easy to install, just follow the instructions in our BUILD section.

Q. Can you put a dryer vent in a window?
A. Yes, REDI2SET windows can be ordered with a dryer vent. There is a photo of one on the basement page in the BUILD section. 

Q. Can you get ventilation through the windows?
A. Yes, REDI2SET windows and Decorative series CrystaLok windows can be ordered with fresh-air vents. The vents are especially made for glass block and come in various sizes. There is a photo of one on the basement page in the BUILD section. 


Q. Does the window come with a frame?
A. CrystaLok windows are unique in that they do come in a frame and can be easily nailed into place. Find more details about CrystaLok glass block windows in the BUILD section.

Q. What is the difference between silicone and mortar joints?

A. Mortar is the traditional material used for assembling glass block and is still preferred for large commercial applications and for showers and partitions. For windows, however, silicone has quickly become the material of choice. REDI2SET and CrystaLok windows are assembled with the Clear Bond System, it gives the windows a bright, clean, all-glass appearance. Modern industrial grade silicones are inert, remain flexible and last practically forever. They also produce a stronger bond and insulate better.