Commercial roofing in Alafaya, FL

Most flat or low-slope commercial roofs need at least a quarter inch of fall per foot to shed water. Built-up, modified bitumen, single-ply and liquid-applied systems each carry that minimum. Ask any bidder to show the slope on the drawings.

Florida's building code treats positive drainage as water leaving the roof within 48 hours of rain. Where the parapet traps water, secondary overflow drains or scuppers are required. Orlando's rainfall, at about 51 inches a year, makes that check worth doing before you sign.

• Confirm the membrane standard the bid names, such as ASTM D4637 for EPDM or D6878 for TPO.
• Ask how the bid handles ponding water and whether a structural review is needed.
• Check that edge metal is designed for the wind loads in Chapter 16 of the code.

Florida law says a contractor who advertises a roof as hurricane or wind-borne-debris protection must hold statewide product approval for it. You can check any product number in the Florida Building Commission lookup before you accept a bid that makes that claim.

Roofing work must be done by a roofing contractor, or subcontracted to one. A general contractor who sells roofing must hold the roofing certification. Confirm the license on the state's lookup, not only on the bid sheet.