0.25" maximum deflection over 50 feet is Span/2400. Gee why would anyone find that unreasonably conservative?
Your live load deflection of L/722 is way more conservative than code, so you have that. Unless something in the project specs could somehow point to a more restrictive deflection...
There is no definite design stress for glass because it does not have predictable breakage characteristics. One can only reduce the probability of breakage by lowering the maximum strength level. For annealed glass under a 60 second load duration LOF recommends a Design Modulus of Rupture in...
