It's my understanding anyway, that you have domed or sloping skylights in conventionl opaque flat roofs; as flat skylights would simply be a trap for debris bird droppings. leaves etc. With a domed or sloping skylight, these are washed away our of sight with the first drop or rain. And maybe cleared away every so often
Whereas with a flat glass roof, its questionable why anyone would need or want skylights in the first place. While any debris would simply wash down off the dome or the slope and settle on the surrounding flat glass.
But as always I'm open to correction on this.
michael adams
Michael Adams ● 1505d