Short answer
A typical interior drain tile job takes one to three days: the crew cuts and removes a strip of floor along the walls, digs beside the footing, lays perforated pipe in washed stone, adds a wall membrane, connects everything to a sealed sump pit and re-pours the floor. On Anderson's wet till, crews often hit water while digging and may add drain lines under the slab where water rises mid-floor.
Knowing what the crew will do each day helps you spot a careful job, and a few steps decide whether the system works for decades.
Before the crew arrives
- Clear 3 to 4 feet of floor along every wall that’s being treated.
- Point out floor drains, plumbing and electrical runs near the walls.
- Confirm in writing which walls get drain tile, where the sump goes, which pump and backup, where the discharge ends, and what happens to the broken concrete.
Day 1: opening the floor
The crew protects the stairs and finished areas, snaps a line about a foot out from the wall, and saw-cuts the slab. Ask whether they use wet cutting or a vacuum shroud to control dust. The strip is broken out and carried out.
Day 1-2: digging beside the footing
The trench goes down beside the footing, to about its top. Digging below the footing can undermine the wall, so that shouldn’t happen without an engineer’s say-so.
On Anderson’s till, expect dense, wet, gray or mottled soil, and often standing water in the trench in wet months. Some crews find old clay tile beside the footing. It’s usually left in place, and the new system is laid next to it.
Day 2: draining the wall
On hollow concrete block walls, which are common in Anderson’s post-war houses, the crew drills small weep holes in the bottom course so water trapped in the cores can drain. A plastic membrane or dimple board goes on the lower wall and into the trench, so water running down the wall ends up in the drain, not on the new concrete.
Day 2: pipe and stone
This is the step that decides how long the system lasts:
- A bed of clean, washed stone in the trench.
- Perforated pipe, often wrapped in filter fabric, sloped toward the sump.
- More washed stone over the pipe.
- Cleanouts at corners so the line can be flushed later.
Under-slab lines. Where water rises through the middle of the floor, the crew may cut additional channels across the slab and lay pipe to the sump. This is more common where the water table is very shallow, as the soil survey estimates for much of Anderson.
Day 2-3: the sump
A sealed sump basin goes in at the low point, with a submersible pump, a check valve and a discharge line through the rim joist to the yard. On Anderson’s wet ground, a battery backup belongs in the same pit. Settle the discharge route now: on your lot, well away from the house, never into a floor drain or the sewer. See discharge and freezing.
Day 3: new concrete
Concrete fills the trench to floor level. The sump gets an airtight lid. The crew cleans up and walks you through the system.
Before they leave
- Pour water into a cleanout and watch it reach the pit.
- Watch the pump cycle on and off, and check that the check valve doesn’t leak back.
- Find where the discharge ends outside, and make sure it’s aimed away from the house.
- Get the warranty in writing, with the walls covered and the installation date, plus the pump manual.
Living through the job
- Noise: saw-cutting and breaking concrete are loud for the first day. Plan around work-from-home calls and pets.
- Dust: even with wet cutting or vacuums, fine dust travels. Close vents to the basement if you can, and change the furnace filter after the job.
- Access: the crew carries concrete and soil out by the bucket, so a clear path from the basement door matters.
- Water and power: crews usually need an outlet and a hose bib. Ask beforehand.
Choosing the crew
Ask each contractor the same questions, and compare the answers in writing:
- Will the trench reach footing level along every wall?
- What stone and pipe, and is the pipe wrapped in filter fabric?
- On block walls, will you drill weep holes?
- Where will the cleanouts go?
- Where will the sump pump go, and who handles electrical permits for its circuit?
- What happens if you find a cracked or moving wall? See crack repair and bowing walls.
Prices for each piece are on the cost page. If water mainly comes in at the floor-wall joint, make sure every wet wall is in the scope.
The first spring
Expect the pump to run often during the first wet season. It’s collecting water that used to sit around and under the basement. That’s the system working. Test the pump and the backup before each spring. The overview of the whole system is on the interior drain tile page.