Gutters in El Portal, FL

The Florida plumbing code ties gutter size to the flow rate off the roof. Its capacity table gives a 6-inch half-round gutter at 1/8 inch per foot about 110 gallons per minute, and a 5-inch one about 74. By our arithmetic, going from 5-inch to 6-inch half-round adds roughly 49 percent more capacity at the same slope. For a sloped El Portal roof, the plan area is multiplied by a pitch factor, so a steeper roof sends more water to the same gutter.

• Gutter capacity follows the flow rate from the roof, not a fixed rule of thumb.
• Count the wall area of any El Portal wall that sheds rain onto the roof, then add half of it to the roof area.
• Downspout size matters as much as gutter size; a 2 1/2 by 3 inch leader carries about 92 gallons per minute only at the larger size.

Florida code requires metal or approved plastic gutters with sound joints and corrosion-resistant fasteners on one- and two-family homes. Gutters are required wherever the eaves project less than 6 inches, except at gable end rakes or where a roof sits above another roof. With 90.1 percent of El Portal's housing units being single-family detached homes, most gutter jobs here fall under this residential rule.

On a lot like this, the water must not pool against the foundation. Check each downspout after a heavy rain. If the discharge lands in the same spot as the house wall, extend it or add a splash block. With 90.0 percent of El Portal's housing units built before 1980, many of these older homes may have downspouts installed before this rule was applied, so check them first. Your local building office can confirm how the village applies this rule to an existing home before you change the drainage.