Hurricane-Rated Skylight Wind Loads for Miami-Dade

Yes, dome skylights typically offer superior wind load performance compared to flat skylights. The curved geometry of dome skylights naturally deflects wind pressure and distributes loads more evenly across the frame, similar to how an egg shell resists crushing forces. Acrylic and polycarbonate domes also offer inherently better impact resistance than standard glazing due to their flexibility. However, both dome and flat skylights must meet the same Miami-Dade NOA requirements and carry appropriate design pressure ratings for their specific installation conditions.

Most existing skylights cannot be retrofitted to meet HVHZ requirements and must be replaced entirely. The reason is that hurricane-rated skylights require specific frame construction, impact-resistant glazing, and tested mounting systems as a complete assembly - you cannot simply swap in impact glazing to an existing frame. Some manufacturers offer protective covers or screens that can be installed over existing skylights, but these typically require their own NOA approval and may not eliminate the need for replacement depending on the original skylight's condition and ratings.

Impact-rated skylights have passed the large missile impact test required in Miami-Dade HVHZ, which involves shooting a 9-pound 2x4 lumber at 50 feet per second at the glazing. After impact, the skylight must maintain its water resistance and structural integrity through 9,000 cycles of pressure testing. Non-impact skylights have only passed wind pressure tests without debris impact simulation. In the HVHZ, all skylights must be impact-rated unless protected by separately approved hurricane shutters or protective screens with their own NOA.

Skylight wind loads on sloped roofs follow ASCE 7-22 provisions for components and cladding on roof surfaces. The calculation considers the roof slope angle (which affects pressure coefficients), skylight dimensions (tributary area determines which GCp values apply), building height (higher buildings have higher velocity pressure), exposure category (open terrain vs. urban), and whether the skylight falls within an edge or corner zone (within 10% of the building width from edges). Skylights on steeper slopes (above 27 degrees) experience different pressure coefficients than those on low-slope roofs, often resulting in lower suction pressures but potentially higher positive pressures during certain wind approach angles.

Yes, tubular skylights and sun tunnels must meet the same Miami-Dade HVHZ requirements as traditional skylights. The dome or lens at the roof level must be impact-rated and carry a Miami-Dade NOA with large missile certification. However, because tubular skylights have smaller opening areas (typically 10-22 inches diameter), they often have easier design pressure requirements to meet. The smaller tributary area results in lower total wind loads, and the compact dome geometry provides inherent strength. This makes tubular skylights a practical alternative when larger skylights would require exceptionally high-rated and expensive products.