Commercial roofing in Auburndale, FL

Florida's minimum design slope for a new low-slope roof is one-fourth unit in 12, which is about 2 percent, for built-up, modified bitumen, single-ply, spray foam and liquid-applied systems. A roof that drains slower than that will hold water after rain. Ask the contractor what slope the finished roof will have and where the water will go.

Florida code calls for positive drainage, meaning the roof should clear water within 48 hours of rain. Where a parapet or wall can trap water, the code requires secondary overflow drains or scuppers. Ask the bidder to show the drain and overflow layout on the plans.

Auburndale has 34 percent of its total area under water, about 7.02 square miles. Heavy rain on wet ground means storm drainage matters for a flat roof here. The storm drainage design in the plumbing code uses the 100-year hourly rainfall rate, so ask how the drains were sized.

The 25 percent rule matters for a building where you plan partial work. Not more than 25 percent of the roof may be repaired or replaced in any 12-month period unless the entire roof system is replaced. Keep a written log of the area done each year so the Office can confirm compliance.

• Confirm the contractor's Florida roofing contractor certification or registration, as Florida law requires for anyone advertising as a roofer.
• Ask which material standard the membrane meets, such as ASTM D4637 for EPDM or ASTM D6878 for TPO.
• Ask whether the bid includes replacing wood sheathing or fascia found during the job.
• Ask for the Notice of Commencement details, since a missed notice can mean paying twice for the work.

Compare bids on the same scope, the same material and the same drainage plan. A low bid that skips the overflow drains or the tear-off to deck fails the code, even if it looks cheaper on paper. Ask the Office whether it will review the plans before you accept a bid.