We have a double glazed conservatory roof approx 45 degree slope, span 3metres, slope length 4.2m approx. The panels are 800m wide and rest on a composite aluminium/plastic roof rafter system. The deflection ay midpoint along the rafter is about 35mm under self weight. Is this safe? Will it still be safe if it has a snow loading?

Any help in calculating what is safe gretly valued.

Needless to say we are in dispute with the contractor who built it!