Canopy weight

[moby da goby]

Are there any concerns I should be awaare of about the weights of enclosed canopies with lights mounted on the inside? My tank has 3/8" glass with no center brace in it. I'm having a custom built oak canopy being completed in the next couple weeks where all of my old and new lighting will be mounted inside. Should have thought of this before I asked someone to build it but too late now.
Any builders of enclosed canopies out there? Let me know your thoughts!
Deanna