Many of the architects we work with come from out of state on a single Florida project. The Florida Building Code, particularly the HVHZ appendix, is different from anything they have specified previously. Here is a short reference written from the contractor's side of the design conversation.
Three things that surprise out-of-state architects
1. Product approval is the gatekeeper
You cannot specify a roofing component in Florida by manufacturer and model number. The product must carry a current Florida Product Approval (FPA) or, in HVHZ, a Miami-Dade Notice of Acceptance (NOA). A perfectly excellent material that does not carry the relevant approval cannot be installed.
When in doubt, look up the product at floridabuilding.org. If it is not listed, the manufacturer either has not pursued Florida approval or the product has expired approval.
2. Attachment is governed by the approval, not the architect
The architect can specify the product and the general installation aesthetic. The attachment pattern — fastener type, spacing, edge zones — is dictated by the product's approval documents. The contractor must install per the approval, not per the drawings if they differ.
Coordinate with your contractor at design development; this is where the assembly is determined.
3. HVHZ inspection is a three-touch process
Dry-in inspection (after underlayment). In-progress inspection (during installation). Final inspection. Each is a hard stop; work cannot continue past the inspection point without sign-off. Schedule accordingly.
Five things to include in your construction documents
Beyond the standard architectural detailing, the following items make a Florida roof spec actually buildable:
The wind zone for the property. Reference the figure number from the Florida Building Code wind speed map.
The roof's exposure category (B, C, or D per ASCE 7). Coastal and barrier-island work is typically D; suburban is C; densely developed urban is B. This drives the uplift calculations.
The mean roof height. Used in the uplift calculations along with the exposure category.
The required edge attachment patterns for the perimeter and corner zones. These are tighter than the field zones; the architectural drawings should reflect this.
The secondary water resistance specification. Self-adhered membrane, product, and coverage area.
Coordination items with the roofing contractor
The conversations that should happen at design development:
- Material selection and its FPA/NOA implications
- Attachment method (RAS 120 vs. 127 for tile; mechanical vs. snap-lock for metal)
- Underlayment system (which product, what coverage)
- Flashing material and detailing
- Ridge ventilation
- Drainage strategy
If these are determined at design development, the construction documents can reference standard details that the contractor has pre-cleared with the inspector. This is faster and produces fewer field changes.
A note on aesthetic vs. assembly
The architect controls aesthetic. The contractor controls assembly. The two intersect at material selection and attachment method. Most contention between architects and roofers comes from one side trying to influence the other's territory.
We work most effectively with architects who tell us what the design intent is and trust us to build the assembly. We work least effectively with architects who specify the attachment method by referencing techniques used elsewhere — typically a different climate, a different wind zone, a different code.
If you are designing in Florida for the first time, the simplest path is to ask the roofer to write the assembly specification, and the architect to write the architectural intent. Both go into the construction documents. Both sign off. The result is a roof that satisfies the design and meets the code.
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