What Thickness Should Glass Step Balustrades Be? If you don't know what you need to do, your renovation project may become stressful. Many people are confused about what should be used for their glass stair balustrades. As well as providing a beautiful addition to your home, balustrades also act as a barrier to ensure that everyone is protected when they are used. If you want to install a glass staircase balustrade, it is very important that you get the right amount of glass. Here are some tips on how to choose the right thickness for your glass stair balustrades.