Gutters in Northdale, FL

Florida's plumbing code sizes horizontal gutters by the flow from the roof. A 5-inch half-round at 1/8 inch per foot of slope carries 74 gpm. A 6-inch carries 110 gpm, about 49% more. Downspouts are rated separately: a 3-inch round carries 92 gpm and a 4-inch round carries 192 gpm.

Roof pitch changes the math. Pitched roofs use plan area times a factor, from 1.00 for low slopes up to 1.30 at 12 in 12. The design basis matters too. By one example from another Florida area, a 6-inch gutter serves more than twice the roof area on a 1-hour, 100-year basis than on the 5-minute burst. Ask any installer which basis they used.

With a median build year of 1986 and 68.8 percent single-family detached homes, many Northdale roofs are likely original or second roofs on older gutter systems. Those systems may be the old 5-inch size. Replacing a roof is a good time to check the size.

Florida Building Code, Residential, section R318.5 requires gutters with downspouts on buildings whose eaves project less than 6 inches. On a Northdale lot, each downspout needs to end 1 foot or more out from the wall, through buried pipe, a tail extension or a splash block. The rule sits in a termite-protection section, so it protects the slab edge too.

Hillsborough County's building office handles roof permits in this census-designated place, which has no city government of its own. Ask them whether a gutter-only job needs one. Whether a state license is required for gutter-only work is unsettled, so check the contractor's license status yourself.

Leaves are the other job. Live oaks drop litter and pines drop needles most heavily from September through November. Insurers and roofing groups suggest cleaning at least twice a year, spring and fall. Clean more often under heavy canopy.