Should extensions be buried or above ground?

Both can work, and the right choice depends on the yard. A buried extension holds its route through the season and is not affected by mowing or foot traffic, while an above ground extension is simpler to install but easier to knock out of place. Epp Foundation Repair recommends based on the slope of the yard and where the water needs to go.

Do downspout extensions replace crawl space encapsulation?

No. Extensions address one source of moisture, roof runoff landing too close to the house. A crawl space can still have humidity from the ground itself, from groundwater, or from air infiltration through open vents, which is why Epp Foundation Repair looks at extensions as one piece of a larger moisture plan rather than a stand alone fix.

How far away from the house should the water be released?

Far enough that it will not simply drain back toward the foundation or a crawl space vent. The right distance depends on the slope of the yard, which is something Epp Foundation Repair evaluates on site rather than applying one fixed number to every home.

Can I install downspout extensions myself?

Some homeowners do. The parts involved are not complicated, but a poorly planned route or the wrong grade can send water toward the foundation instead of away from it, or leave the pipe pooling water partway along its run. If a downspout is already part of a larger crawl space moisture problem, having it assessed alongside the rest of the crawl space is worth the on-site look.

3D rendered illustration of a fully encapsulated crawl space showing wrapped support pillars, a dehumidifier unit and white vapor barrier walls

Crawl Space Repair · Solution · Since 1994

Keep Roof Water Away From Your Crawl Space Vents and Foundation

Epp Foundation Repair installs downspout extensions as part of a broader crawl space moisture plan, moving concentrated roof runoff away from the vents and soil that feed humidity into the space below your home.

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How it works

Downspout Extensions: how it works and when it's the right call.

Epp Foundation Repair routes discharge pipe from a problem downspout to a point well away from the foundation, either buried underground or run along the surface depending on the yard and the homeowner's preference. A buried extension is pitched on a steady, gentle downhill grade so water keeps moving toward the discharge point instead of pooling partway along the run. That discharge point is typically daylight on a downslope, a pop-up emitter set flush with the lawn, or a tie-in to an existing drainage system already installed on the property. A pop-up emitter opens when water arrives under pressure from the downspout and closes again between rains, which keeps debris and small animals out of the pipe. Above ground extensions and splash blocks can work for a home with the right slope away from the foundation, but they are easy to knock out of place with mowing equipment or foot traffic, and a buried line holds its route through the season. Epp Foundation Repair maps the route to avoid tree roots, irrigation lines, and other buried utilities before any digging starts, and confirms the discharge point is actually clear of the foundation and any crawl space vent before calling the work finished.

Downspout Extensions explained by Epp Foundation Repair

Installation Process

How we install downspout extensions.

Step 01.Walk the property and identify problem downspouts

Epp Foundation Repair checks each downspout to see how close it discharges to the foundation and to any crawl space vent, ideally during or right after a rain when the pattern is easiest to see. Not every downspout on a home needs an extension. Often only one or two are actually contributing to the moisture problem.

Step 02.Plan the route and pick a discharge point

The route is planned to avoid trees, irrigation lines, and other buried utilities, ending at a discharge point far enough from the house that the water will not simply soak back toward the foundation or crawl space vents.

Step 03.Install the extension

For a buried run, the crew trenches, lays pipe on a steady grade toward the discharge point, and sets a pop-up emitter or daylight outlet. Sweep elbows are used at turns so debris does not catch and clog the line.

Step 04.Confirm the discharge point stays clear

Epp Foundation Repair checks that water actually leaves the pipe and moves away from the house rather than pooling at the outlet, which matters just as much as getting it away from the foundation in the first place.

"Standing water in a crawl is the call where I tell the homeowner not to wait the weekend. You've got 48 hours before mold starts on a joist that's been sitting in water. I'd rather you call the restoration company first and call us second. Get the water out today, and we'll be there next week to make sure it never comes back."

Dave Epp

President, Epp Foundation Repair

Why Choose Epp

Care and expertise from a team that's been doing this since 1994.

Epp Foundation Repair is locally owned and operated, with crews dedicated exclusively to foundation, basement, and concrete work across the Midwest.

Specialized expertise.

Foundation repair, waterproofing, and concrete leveling are our entire focus, not a sideline.

Locally owned since 1994.

Three decades of experience with Midwest soils, basements, and weather conditions.

BBB Integrity Award winner.

Recognized in 2011 and 2016 for ethical business practices and customer transparency.

Warrantied solutions.

Every repair comes with a written Epp warranty, from 1 year to the lifetime of the structure depending on the product.

Epp · Since 1994

Why hire Epp Foundation Repair.

MEET THE TEAM · 2 MIN

Frequently Asked Questions

Answers to common questions about Downspout Extensions.

Don't see your question here? Our team is happy to help. Reach out anytime.

A downspout with no extension releases a concentrated stream of water at the corner of the house, often close to a crawl space vent or the foundation wall. That water soaks into the ground right where the crawl space is most exposed, which works against any other moisture control measures in place. Extending the downspout is one of the simplest ways to reduce that load.

Any figures shown above are general context only and are not project quotes. A precise figure is provided on the Customized Repair Estimate after on-site inspection.

Crawl Space Repair warning signs this solution resolves.

Each problem sign below is a symptom this solution is engineered to fix. See how we diagnose it before we recommend this method.

Epp Foundation Repair inspecting crawl space mold and decaying wood from water damage in Lincoln, NE.

Moisture in Crawl Space

Epp Foundation Repair has been encapsulating crawl spaces across Nebraska, Iowa, Kansas, and Missouri since 1994, dropping relative humidity from 75%+ down to a stable 50 to 55%. The threshold where mold cannot colonize.

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Standing Water

Epp Foundation Repair has been installing emergency crawl space waterproofing systems across Nebraska, Iowa, Kansas, and Missouri since 1994. Mold colonization begins on saturated joists within 48 to 72 hours of standing water.

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Epp Foundation Repair identifies standing water and moisture in a dark, wet crawl space with wooden beams.

Groundwater Seepage

Epp Foundation Repair has been installing interior crawl space drainage and sump systems across Nebraska, Iowa, Kansas, and Missouri since 1994. The only permanent answer to seepage driven by a high spring water table.

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Crawl Space Mold

Epp Foundation Repair has diagnosed crawl space moisture conditions across Nebraska, Iowa, Kansas, and Missouri since 1994. Mold spores exist in every crawl space. They only colonize when humidity stays above 60% for 48 hours or more.

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Deteriorating Insulation

Fiberglass batts drooping between your floor joists or falling to the crawl space dirt. The insulation itself is the symptom. The cause is humid air and ground moisture that the insulation can no longer hold back.

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Epp Foundation Repair illustrating crawl space repair benefits with stacks of cash in a dark crawl space.

High Energy Bills

Heating and cooling costs creeping up while your thermostat stays the same. A damp, vented crawl space pulls in outside air and lets conditioned air leak out through the floor. Your system runs longer to make up the difference.

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Service Areas

Serving Nebraska, Iowa, Kansas & Missouri.

Local crews based in five regional offices, dispatched daily across four states. If your town isn't listed, call us: we likely serve your area.

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Our Process

Take the first step toward a healthy home.

A straightforward path from initial inspection to completed repairs.

Step 01

Schedule your inspection.

A local specialist visits your home, evaluates the foundation, and answers your questions on site. No cost, no obligation.

Step 02

Receive an estimate based on your needs.

We provide a clear, Customized Repair Estimate with a scope of work tailored to your home's specific issues. Typically within one business day.

Step 03

Get your repairs.

Our own trained crews complete the work on schedule and back it with a written Epp warranty, set out in your contract.

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