Commercial roofing in Celebration, FL

Most flat or low-slope commercial roofs in the state use built-up, modified bitumen, or single-ply membranes. The Florida Building Code sets a minimum design slope of one-fourth unit in 12, or 2 percent, for these systems, so a roof that drains poorly may need additional slope work during replacement.

• Request the drainage plan and note where water stands after a storm.
• Where a parapet wall could trap water, ask if the bid adds an emergency overflow path.
• Look for the membrane's ASTM standard in the bid itself: D4637 applies to EPDM and D6878 to TPO.

The code asks for positive drainage, meaning the roof drains within 48 hours of rain. Celebration gets heavy summer rain, so ask the bidder how the design handles that. The county normals show 24.77 inches of rain in June through August at Kissimmee 2, about 47 percent of the year, by our arithmetic.

Compare bids on the same scope. Each should describe the existing roof condition, say whether a tear-off to the deck is included, name the membrane product and standard, and state the drainage correction. A bid missing any of those items cannot be measured against the others.

Recovering over an existing roof is barred where the old roof is water soaked, has two or more prior coverings, or has blisters that were not cut and secured. If a bid proposes a recover over a roof like that, ask the bidder to explain why it meets the code.

Ask each bidder to confirm which contractor will hold the roofing scope. Florida law requires a certified or registered roofing contractor for roofing work, so ask for the license number and check it against the state record.