ceiling from "bowing in"

[lizardlover123]

So I was looking at vivs. because I am making my own and I was wondering how to keep the ceiling from "bowing in" because, over a large surface, without support in the middle, plywood will bow. Do I make a ceiling frame or 2 posts in the viv? or is 3/4 inch thick enough that a 6'X3'X2' will not bow? It is a pretty large surface area. Thanks.

 

[Silvercold88]

Don't know if you still need an answer but I'd use 3/4 Mdf. Will now bow or bend like plywood

 

[TheGreganater]

Easiest way to prevent bowing in plywood is making the ceiling frame,
6'X3'X2
Figuring you mean 6 feet length, 3 feet depth and 2 feet height?
Easiest way i have think is making an rigid frame for the top