Florida roofing code is driven by wind. What is required at your address depends on the wind zone, the roof height and whether you are in a high-velocity hurricane zone.
Materials need Florida Product Approval or a Miami-Dade NOA covering the specific system and fastening pattern for your wind zone. Ask for it with your written scope.
Re-roofs commonly trigger a requirement to bring existing deck fastening up to current standards. This is one of the most frequently omitted items on a cheap quote.
Where required, a sealed secondary water barrier at the deck seams provides protection if the covering is lost in a wind event.
A roof installed under an earlier code edition was legal then and is not compliant now. That gap matters at replacement and on wind mitigation paperwork.
O'Brien Contracting — Florida roofing contractor, license CCC1335947. Call (239) 919-4485.