Gutters in The Crossings, FL

The plumbing code sizes gutters from the flow off the roof, and the design rate matters a great deal. NOAA Atlas 14 gives The Crossings a 1-hour, 10-year rain of 3.36 inches an hour, and a 24-hour, 10-year total of 8.35 inches. Short bursts are what overwhelm a gutter, so the 5-minute figure is the number to test your system against.

Illustration

Illustration: half round copper

Miami International Airport averages 67.41 inches of rain a year, with 89.6 days at 0.10 inches or more. Most of that falls in the wet season. About 77 percent of the airport's normal annual rain comes from May through October. Gutters here carry a lot of water for many months, not just during storms.

About 51.6 percent of the housing units here are single-family detached homes, so many roofs drain to their own gutters and downspouts. With a median build year of 1981, many of these systems are likely original or well worn. That suggests checking hangers, seams and slope before the wet season.

• Check that each run is 5 inch or 6 inch half-round, or a rectangular size the code table allows.
• Confirm each downspout is at least 2 by 3 inches for the roof area it drains.
• Add half the area of any wall that sheds water onto the roof when you size the system.