Question:

Dear Glass Detective,

I would like to re-purpose a 1/4″ (6mm) tempered glass shower door as a sloped awning over an entry. The dimensions of the glass are 30″x60″. My question is whether there is a chart available that can tell you what thickness of glass is needed for what loads? There would be a 40″ span, 30″wide of unsupported glass. We are in Vancouver, BC so do not get much snow, but we do get some. Would doubling the glass doors up (two are available) make any difference or would they have to be laminated for the doubling to make them stronger?

Thanks for sharing your expertise!
Brenda

Answer:

Brenda, 

Thank you for contacting the Glass Detective with your question regarding the re-purposing of a piece of tempered glass from a shower door into an “awning” over an exterior door.  Based on the information you have provided, I am going to suggest the following: Examine the piece of glass carefully and somewhere on the glass there should be an identifying logo which will indicate who manufactured the glass in question. If there is no identifying logo, I would not use the glass for any purpose. Once you have identified the manufacturer, you might be able to track them down and see if they can tell you what the piece of glass is capable of handling from a “load” standpoint. I don’t see any advantage in “doubling the glass” up unless you laminate it. I am not familiar with Canadian codes but the application you are describing would not comply with overhead glazing codes in the United States. It might comply if it were laminated to another piece, but again, I am not familiar with your codes and really cannot tell you what loads a given piece of glass might be able to withstand. I wish you good luck with your project.

-Glass Detective