Gutters in Belleair Shore, FL

The plumbing code sizes horizontal gutters by roof flow rate. A 6-inch half-round gutter at 1/8 inch per foot carries 110 gpm, while a 5-inch one carries 74 gpm. That gap is roughly 49 percent, so the size you choose changes the outcome.

Downspouts follow their own table. A 2 1/2 by 3 inch leader handles 30 gpm, and a 3 inch round leader handles 92 gpm. If the roof area feeding a single downspout is large, one small leader can overflow even when the gutter above it is correct. Count half of every wall's area when that wall drains rain onto the roof.

Sizing also depends on the design basis. On the code's 100-year, one-hour rate, a 6-inch half-round serves much more roof area than it does on the shorter, more intense burst that older sizing tables use. Ask your installer which basis they used.

Under Florida's residential code, downspout outlets must sit no closer than 1 foot to the sidewall. You can reach that clearance with buried pipe, extended tails or splash blocks. A downspout that dumps at the foundation edge fails the rule, and it can soak the soil under your home.

• Gutters are required on homes with eaves under 6 inches, except at gable rakes.
• Gutter and leader joints must be lapped, soldered or caulked.
• Fasteners must be corrosion resistant and suited to the gutter metal.

Ask whether the downspouts on your home discharge away from the foundation. Also check whether a permit covers gutter work on your home. Pinellas County Building Services handles permits for Belleair Shore.