Gutters, Downspouts and Lot Grading: How Water Should Leave the House

Water should leave a house by three routes: off the roof into gutters, out through downspouts that discharge away from the walls, and across soil that slopes away from the foundation. If any one of those fails, water ends up at the foundation, and that is where basement and crawl space problems start. The best time to check is during or right after a rain, and you can ask your agent to schedule a second showing for that reason.

Here is what to look at, what published guidance says about slope and downspout distance, and what a Virginia home inspector covers.

How water is supposed to move

The Northern Virginia Soil and Water Conservation District, a Fairfax County conservation program, explains on its page Gutters and Downspouts: Wetness or Erosion Problems that wetness or erosion near foundation walls and the drip line can cause serious damage. It names clogged or undersized gutters, downspouts and sump pump pipes, and poor grading as common sources. Its guidance is that land around a house should slope away from the foundation, at a 5 percent grade for about 10 feet. That works out to roughly 6 inches of fall over 10 feet, which is a number you can check with a level and a tape.

The same page says to fill depressions near downspouts, clean gutters at least once a year (more often with trees close to the house), and look for streaks, watermarks or erosion along the drip line as signs of overflow.

A walk-around checklist for a showing

1. Start at the roof edge. Look for sagging gutters, gaps at the seams, plants growing in them, and stains on the fascia or siding below.
2. Follow each downspout to the ground. Where does it end? Virginia Cooperative Extension’s fact sheet on rooftop disconnection (Publication 426-120, Virginia Tech, 2019) says to place downspout outlets at least 5 feet from any building. That guidance is written for a specific stormwater practice, so use it as a reference point, not a code requirement.
3. Look for a splash block, extension or buried pipe. The conservation district page describes splash blocks and non-perforated corrugated pipe extensions as ways to carry water farther from the wall.
4. Check the soil along the foundation. It should fall away from the house. Low spots, bare channels, or soil that sits against siding are worth a photo.
5. Look at hard surfaces. Cracked or tilted patios, walks and driveways can tip water toward the house.
6. Check the inside edge. In the basement or crawl space, look for stains, efflorescence (white mineral deposits), damp smells or a dehumidifier running in a corner.

What to look for after a rain

A dry day hides most drainage problems. During or soon after rain, watch for water spilling over a gutter edge, water pouring out of a seam, puddles that sit at the foundation, and downspouts that dump next to the wall. The conservation district page says that if gutters overflow in normal rain, larger gutters are an option, and where replacement is costly or hard to reach, a gravel band or dense ground cover can protect the soil beneath. Sellers and listing agents can tell you whether the gutters have been cleaned recently, but you can only verify the soil yourself. Take photos of each corner of the house and each downspout outlet, with a tape measure or your shoe in the frame for scale, so you can compare houses later.

Inside the house, water can show up differently. Look at the lowest floor, around floor drains, and under windows near ground level. Our guides to wet crawl spaces and sump pumps go deeper on what you find when exterior water gets in.

What a Virginia home inspector notes on drainage

Virginia’s home inspector standards, 18VAC15-40-130, list gutters and downspouts under roof drainage in (C)(2)(c), and grading, drainage, vegetation, trees and adjacent retaining walls under (C)(3)(f). Walkways, grade steps, patios and driveways fall under (C)(3)(e), though fences and privacy walls are excluded. Everything is limited to what is readily accessible and observable, and an item not inspected must be explained in the report.

The inspector can tell you a gutter is loose or the grade slopes toward the house. The inspector does not design a repair or predict how the house will behave in a storm season. For a structural or engineering question about a foundation, ask for a specialist inside your inspection period. Our Richmond home inspection guide shows how to line up that follow-up.

Lots that slope, and what to ask about

Some lots sit below the street or below a neighbor’s yard. Whether you tour in Forest Hill, Midlothian or anywhere else, notice where water from the street and the yard next door goes, and whether the lot is higher or lower than its neighbors. VCE’s fact sheet limits simple downspout disconnection to gentle slopes, under 2 feet of drop per 100 feet, to avoid erosion, so a steep side yard needs more than an extension pipe.

Ask the seller whether water has ever come in, whether gutters or grading were changed, and whether a downspout is tied to a buried pipe, since a blocked buried pipe is hard to see. If you plan to regrade or add drains, check the permit requirements with the locality.

Planning for the repair

Gutter cleaning, extensions and minor regrading are the kind of tasks owners often handle in stages, while a drain or foundation repair is a bigger decision. Run your target price and monthly payment with our mortgage calculator before you decide how much repair work you can take on, and ask a lender on our preferred lenders page about financing options.

Frequently asked questions