Drainage on a steel skylight
Zhangjiagang plot 2011-B16 is a steel skylight. Water has to leave the rafters, not the glass only.
Related scope
Steel skylights and canopies
Steel skylights and steel canopies, including glass canopies that sit inside a window contract.
Pitch and outlet
State the fall, the outlet location, and whether the water drops to a roof drain or to a facade. A flat drawing with no fall cannot be priced as a drained skylight. The draft on the product page mentions channels in the rafters for this reason.
Condensation is the second path
Insulated overhead glass still produces condensate on the frame in cold weather. Ask whether the rafter has a condensate gutter. That gutter is not the same piece as the rain channel.
A water test before the ceiling closes
Test the skylight with water before the interior ceiling hides the rafters. Record where it leaks: glass joint, rafter, or outlet. A leak found after the ceiling is closed is no longer a glazing repair only.
