Service
Interior Drainage and Sump Pump Installation in Janesville, WI
Interior drainage and sump pump installation in Janesville, WI runs roughly $3,000 to $12,000 for a drainage system and $600 to $2,500 for an installed pump, according to 2026 national cost guides. We install the drain, the sump basin, and the pump with battery backup, and every job starts with a free inspection and a written price. Call 123-456-7890 to book yours.
What Interior Drainage Does for a Janesville Basement
Interior drainage collects water at the base of the wall and moves it out before it reaches your floor. Water pressure in saturated ground pushes it through the floor-wall seam, through mortar joints, and through cracks. We don't try to block that water at the surface. We give it a channel and a pump, which takes the pressure off the wall.
It's the method we install most often, and it fits both block and poured concrete walls. It works from inside the house, so there's no digging up the yard, and it can go in during any season, including a frozen Wisconsin winter.
What We Install
We cut a drainage channel along the footing. We open a strip of slab beside the wall, set perforated pipe in gravel, and patch the floor over it. Water at the floor-wall seam drops into the pipe instead of spreading across the basement.
We set the sump basin and pump. The pipe runs to a basin below the floor, and the pump sends the water out through a discharge line to the yard, away from the foundation.
We add a battery backup. A storm heavy enough to flood a basement can also cut the power, and a standard pump stops when the power does. The backup pump keeps running on its own battery. Our guide to sump pump failure and battery backup covers why pumps stop and how to test yours.
We drill weep holes in block walls. Block is hollow, and water collects inside the cores. Weep holes in the bottom course let that water drain into the system instead of sitting in the wall.
Work is performed by independent professionals.
How it works
How Interior Drainage Gets Installed
First, we inspect the basement and mark where water enters.
Second, we open the slab along the wall that needs drainage and set the pipe in gravel.
Third, we install the sump basin and the pump and run the discharge line outside.
Fourth, we add the battery backup and, on block walls, drill the weep holes.
Finally, we pour the patch, test the pump with water, and confirm the discharge moves the water away from the house.
Why Janesville Basements Need It
The Afton-Janesville weather station records about 37 inches of precipitation and about 37 inches of snow in an average year, and March through June adds up to about 14.7 inches of precipitation. That water soaks the ground around a foundation, and the pressure finds the weakest point. About 28% of Janesville's occupied homes were built between 1960 and 1979, and another 27% before 1960, so many basements went in before modern drainage and rely on walls and floor joints that were never sealed.
Storm runoff is the other load. When flash flooding hit Janesville on April 17, 2026, storm runoff flowed into Janesville basements. A drain and a pump sized to the water give a basement somewhere for that water to go. For the local picture, see Rock River flooding and Janesville basements.
When Interior Drainage Is the Right Call
Interior drainage fits when water gathers at the floor-wall seam, seeps through the base of a block wall, or comes up through the floor after rain or snowmelt. It's the lower-cost method and the least disruptive. It's not the answer for every wall. If water comes through the face of the wall, or a footing drain has failed, we look at exterior waterproofing, and a wall that has cracked or started to bow needs wall repair. Our guide to interior vs exterior waterproofing lays out how we choose.
What Interior Drainage Costs in Janesville
Published 2026 national cost guides put interior waterproofing at roughly $3,000 to $12,000 and an installed sump pump at roughly $600 to $2,500. Those are national averages, not Janesville quotes. The length of wall treated, the foundation's condition, the pump size, and the battery backup all move the price. We set a written price after the inspection, before any work begins. What basement waterproofing costs, and what changes the price
Frequently asked
Frequently Asked Questions
Does interior drainage stop a basement from leaking?
Interior drainage stops water from reaching your basement floor by collecting it at the base of the wall and pumping it outside. It takes the pressure off the wall's floor joint and weep holes, which is where most Janesville basement water shows up. It doesn't change what's happening in the soil outside. A wall that leaks through its face or has cracked may also need exterior waterproofing or wall repair, and the inspection tells us which.
Do I need a battery backup sump pump?
A battery backup is the most important addition to a sump system, because a storm heavy enough to flood a basement can also cut the power. A standard pump stops when the power does, and the basement fills at the moment the pump matters most. The backup runs on its own battery and keeps pumping until power returns. We include it in the plan we write for a Janesville home.
Will interior drainage work on block walls?
Interior drainage works on block walls when weep holes are drilled in the bottom course. Block is hollow, so water collects inside the cores and weeps out through the mortar joints. The weep holes let that water drain into the pipe along the footing instead of sitting in the wall. We include them on block foundations, which are common in Janesville homes built from the 1960s on.
How much does a sump pump cost in Janesville?
National cost guides published in 2026 put an installed sump pump at roughly $600 to $2,500. That's an average, not a Janesville quote. The price depends on the pump's size, the basin, the discharge line, and whether a battery backup is added. An on-site inspection gives the real number, and we put it in writing before work begins.
Can interior drainage be installed in winter?
Interior drainage can be installed in any season, because the work happens inside the basement and doesn't depend on thawed ground. That matters in Janesville, where the weather station records about 37 inches of snow a year and March crosses freezing nearly every day. If your basement leaks during snowmelt, waiting for spring isn't required.
Get a Free Interior Drainage Estimate in Janesville
For a free estimate on interior drainage and a sump pump in Janesville, call 123-456-7890. We'll inspect the basement, find where the water comes in, and write up a price. You can also reach us here or start from our Janesville basement waterproofing page.