Gutters and Drainage on FEMA-Elevated Homes

After Sandy, many homes on Long Island's South Shore were elevated. The result looks simple: the house goes up and the flood risk goes down. But elevation changes how a home drains water, and the gutter and drainage work needs to account for the new geometry.

What elevation changes about drainage

On a house at grade, a standard leader carries water from the gutter to the ground, where a splash block or extension sends it away from the foundation.

Raise that house on piers or fill and the geometry changes:

• The gutter is now much higher above grade.
• The leader has to span that full height, with the right number of elbows and secure bracing along the wall.
• The discharge point at grade is at the base of a pier field, not beside a conventional foundation.
• The soil around the piers is often disturbed or added fill, not the original ground the drainage was designed around.

Original downspout routing assumptions may no longer apply, so an elevated home should be treated as its own job and not as a standard gutter replacement.

Four things to get right

1. Leaders that run to grade.

A leader that stops short of grade dumps water against a pier or block infill. That saturates the area, can undermine footings, and can wick moisture into framing above. A full-length leader should terminate at grade with an extension that directs water away from the pier field.

2. Directing the discharge.

A pipe end at grade without direction sends a concentrated stream into the soil beneath it. Around fill material, that can erode the soil and expose the pier. Extensions, splash blocks or pop-up emitters should carry water well clear of the base of any pier before it spreads out.

3. Underground drains that predate the elevation.

Many South Shore homes had underground drainage before the storm. Some of it was damaged, and elevation changed the grade around the rest. A drain that worked at the old grade may now be at the wrong depth or terminate somewhere unintended. Before connecting a leader to underground drainage on an elevated home, verify where the drain actually goes. Until it is confirmed, treat the system as suspect.

4. Gutter pitch against the new eave.

If gutters were re-mounted after elevation without checking slope, they can hold water, pool at low spots and overflow at the fascia. Standing water in the gutter after rain, or corrosion at the same spots each time, points to this.

Flood zones and drainage

Properties in AE and VE flood zones can have drainage and construction requirements beyond standard residential code, and rules vary by municipality. Check with your building department or your design professional about what applies to your site. As a general principle, discharge that is aimed at piers, into fill or toward a property line causes problems whatever the zone.

Material choice

For South Shore homes, a 6" gutter is worth serious consideration over a 5". Nor'easters deliver rain quickly, and a gutter that cannot move the volume overflows at the fascia. On an elevated home the fascia is far off the ground and harder to repair.

Salt air and humidity are also harder on aluminum than a national product spec assumes, so gauge matters. Close to the water, copper becomes a serious option. A home that was elevated at great expense deserves a gutter system chosen for the exposure.

Questions worth asking any contractor

Elevated homes are different from standard jobs, and a few questions help you judge whether the quote reflects that.

• What elevation system is the house on? Concrete piers, block infill, engineered fill and crawlspace elevation each have different drainage considerations.
• Will leaders run to grade? They should, with discharge directed away from the piers.
• How will existing underground drains be checked before a connection? They should be verified, not assumed.
• Have they done comparable work? Ask to see photos of similar homes, without owner names or addresses.

The elevation was an expensive, disruptive investment in protecting the house. The drainage and gutter work should support it. If you have an elevated home and want it looked at, get a quote.