b'SkylightsPreference and light requirements ultimately determine which type of skylight is best for which type of building, but given that most com-mercial roofs are flat, a curb-mounted skylightsitting on a wood or steel curb lifted up off of the surface of the roof structureis always the best choice. With older buildings, drainage is a concern, says Ferrazzo, and the curb just helps to lift the skylight up off of that surfaceabove the waterline, so to speak.For all of the advancements in skylight technology, the signs that a skylight needs replacing remain the same. The first and most obvious one, says Ferrazzo, is leakage; if there is water penetration through that skylight, its time to go. If there are any visible cracks in the lenses, its also time to replace. Finally, if the exterior framing of the skylight is cracked or misshapen for whatever reason, that could compromise the drainage capability of the skylight.The trend toward using more skylights is so positive, says Fer-razzo. There are countless studies out there that demonstrate natural light on the interior of a building helps elevate the mood, concentra-tion and focusing ability of the occupants. Natural light is everything.10ONTARIO ROOFING NEWSISSUE 2 2019 THE ONLY SOURCE FOR PROFESSIONAL ICI ROOFING CONTRACTORS IN ONTARIO ORN'