Stop Roof Runoff From Flooding Your Foundation
A downspout that terminates at your foundation dumps concentrated roof runoff directly against your basement wall with every rain. Ground Up installs proper extensions to carry that water safely away.
On cost: $150 – $800
Overview
Downspout Extensions
Your gutters collect a surprising amount of water during a Middle Tennessee rainstorm, a typical roof can shed hundreds of gallons per inch of rainfall. When downspouts discharge that volume at the base of your foundation, the surrounding soil becomes saturated quickly, creating the hydrostatic pressure, the force that saturated soil places against your basement wall, that drives basement moisture and flooding. Ground Up Foundation Repair installs downspout extensions, including surface extensions, flexible rollout models, and underground piped discharge systems, to move roof runoff well away from your structure before it can become a basement problem.
Downspout extensions lengthen the discharge point of your gutters so roof runoff exits far enough from the foundation to prevent soil saturation near the structure. Simple surface extensions redirect water 4 to 6 feet away at grade level. Underground systems bury the discharge pipe beneath the surface and carry water to a pop-up emitter, dry well, or outfall set 10 feet or more from the foundation. Underground systems are particularly effective where surface extensions would cross walkways, driveways, or landscaped areas.
Wondering if this is the right fix for what you are seeing? Learn more about the warning signs: Basement Flooding and Basement Water Intrusion . Or browse the full Problem Signs library for basement waterproofing.
Installation Process
How we install downspout extensions
Downspout and Discharge Point Assessment
We inspect all downspouts to confirm they are properly connected to gutters, free of blockages, and positioned to discharge away from the structure. We identify where each downspout currently terminates and evaluate what type of extension is most appropriate.
Extension Type Selection
Based on your site layout, we recommend the right extension type for each downspout, surface extenders for open yard areas, rollout models for occasional use, or underground piped systems where surface routing is not practical.
Surface Extension or Underground Pipe Installation
Surface extensions are connected to the downspout outlet and secured to grade. Underground systems require trenching from the downspout to the discharge point, with PVC pipe laid at the appropriate slope and covered with a pop-up emitter at the exit.
Discharge Point Positioning
All discharge points are positioned to release water at a location where it can flow freely away from the house without pooling. We confirm the outlet location does not direct water toward a neighbor's property, septic system, or other sensitive area.
System Test and Site Cleanup
We test each extension with water flow to confirm proper drainage and no leaks at connections. Disturbed landscaping and turf are restored and the work area is left clean.
Downspout extensions are one of the simplest and most overlooked fixes in waterproofing. Getting roof runoff 10 feet away from the foundation costs very little and can make a measurable difference in basement moisture levels.
Why Ground Up
The difference is in the diagnosis
Get several quotes and you'll see a wide range of prices. The gap isn't luck. It's whether the contractor finds the actual cause and stands behind the work.
- In-house certified crews: we never subcontract your repair
- Optional independent third-party engineer review on larger jobs
- Honest three-tier triage: we tell you what can wait, in writing
- Family owned from the same Shelbyville Highway address since 2009
FAQ
Downspout Extensions questions
At minimum, downspout extensions should discharge water at least 4 to 6 feet from the foundation. Where possible, 10 feet or more is preferable. Underground systems can carry water even farther, which is ideal for homes on smaller lots where surface routing is limited.
A surface extension is a rigid or flexible tube attached to the end of the downspout that redirects water across the ground. It is visible, easy to install, and low cost. An underground system buries a PVC pipe beneath the yard and uses a pop-up emitter at the exit point, keeping your yard clear and handling higher water volumes more reliably.
Simple surface extensions are DIY-friendly and widely available at hardware stores. Underground discharge systems involve trenching, proper pipe slope, and correct emitter placement, mistakes can direct water toward your foundation rather than away. Ground Up can handle the full installation to make sure it is done right.
Downspout extensions address one major source of foundation-level saturation. If your basement moisture is also driven by groundwater, poor yard grading, or lateral soil pressure, you will need additional solutions. Ground Up evaluates all contributing factors and recommends the right combination of measures.
Surface extensions should be checked seasonally and cleared of debris. Underground systems should have their pop-up emitters inspected each spring and fall to confirm they open properly and are not clogged with sediment or plant material.
More Solutions
Other solutions we offer
Exterior Waterproofing Membranes
Exterior waterproofing membranes are applied directly to the outer face of the foundation wall after excavation exposes the wall from footing to grade. The membrane forms a continuous moisture barrier across the entire exterior wall surface, sealing cracks and preventing water under hydrostatic pressure, the force that saturated soil exerts as it presses against the wall from outside, from migrating through the concrete. When combined with a foundation drainage board and footing-level drain tile, exterior waterproofing provides the most complete protection available for a basement. Ground Up Foundation Repair installs exterior waterproofing as a standalone system and as part of combined interior-exterior waterproofing packages for severe water intrusion situations.
French Drain Installation
French drains are subsurface drainage systems that intercept and redirect groundwater, surface runoff, and laterally migrating soil moisture away from a foundation or problem area. A trench filled with clean stone and a perforated drain pipe captures water moving through the soil and carries it by gravity to a safe discharge point. Ground Up Foundation Repair installs French drains as perimeter foundation drains, yard drainage solutions, and hillside intercept drains for Middle Tennessee properties where groundwater movement or surface drainage is contributing to basement moisture, yard flooding, or saturated soil conditions.
Grading & Yard Sloping
The ground immediately surrounding your home should slope away from the foundation at a minimum grade of 6 inches over the first 10 feet. When that slope is flat, reversed, or has settled unevenly over time, rainwater and snowmelt drain toward your basement instead of away from it. Ground Up Foundation Repair corrects improper yard grading across Middle Tennessee by adding and reshaping soil to establish the right slope profile, one of the most cost-effective steps a homeowner can take to prevent basement moisture problems.
Interior Drainage Systems
An interior basement drainage system is the most reliable long-term solution for chronic basement water intrusion in Middle Tennessee homes. Rather than attempting to stop water at the exterior, an interior system accepts that some water will reach the foundation and channels it away harmlessly before it can cause damage. Ground Up Foundation Repair installs complete interior drainage systems including perimeter channels, sump basins, and primary and battery backup pumps sized to handle the water volumes common during Middle Tennessee storm events.
Vapor Barriers
Basement vapor barriers are heavy-duty polyethylene or reinforced sheeting systems installed on foundation walls and floors to prevent moisture vapor from migrating through concrete into the living space. In Middle Tennessee's humid climate, unsaturated concrete walls and floors can transmit significant moisture even when no active seepage is present, enough to sustain mold growth, warp wood, and keep relative humidity at damaging levels. Ground Up Foundation Repair installs vapor barriers as standalone moisture control systems or as part of a complete interior drainage and waterproofing package.
Yard Drainage Solutions
When your yard fails to drain after rain, water pools against your foundation and soaks into the surrounding soil. Over time, that sustained hydrostatic pressure, the force of that saturated soil pressing against your foundation walls, forces moisture through basement walls and floors, leading to flooding, mold, and structural damage. Ground Up Foundation Repair installs comprehensive yard drainage systems across Middle Tennessee, including catch basins, channel drains, pop-up emitters, and underground discharge lines, engineered to capture surface runoff and route it safely away from your home.
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