Hello everyone. Today I would like to share with you a basic glass thickness guide.
Before the details, here are some clarifications that you should know. The thickness of the glass is mainly dependent on the ratio of the tank’s length vs the tank’s height. To calculate the glass thickness, the width of the tank is not important.
The above table is made based on glass thickness available in our country. Please note that, 21mm and 24mm glass are not available in Bangladesh to the best of my knowledge, but mentioned here for information only. Glass tanks should not exceed the length of 96” and height of 36” usually. When selecting your tank size to build, it is advisable to go with a dimension which is multiple of 6”, because that is how glass is sold. If you want say 21” height, they will still charge you for 24”. So don’t waste the money; and bigger the tank the better it is.
Bracing the top of the tank is very important. It provides support and makes the tank safe, greatly minimizes glass bowing, and ensures a leak-free tank for many years to come. In my opinion, you should brace the top of any tank that has a length of more than 24”. It is always better to be safe than to be sorry. When putting on bracing, the thickness of the glass for the brace should be SAME as the thickness of the tank’s glass. Also, the braces should be at least 2” wide. Below are some examples of bracing that can be done on the top of the tank:
When we calculate the thickness of glass required, there is a mathematical calculation involved, which is called safety factor. I will not go into the complex mathematical calculation involved. But you should know that, ideally a safety factor of 3.8 is used for braced tanks to consider it SAFE. A safety factor of 3.9 and above is used to consider the tank VERY SAFE. For a braceless tank, usually a safety factor of 5+ is considered.