Basement waterproofing.

Three kinds of water

River Forest sits on clay, close to the Des Plaines, with a combined sewer system and ninety-year-old foundations. Water gets into basements here three different ways, and the first job is figuring out which one you have.

Surface water is rain that lands near the house and soaks down along the foundation wall. It shows up as damp walls or seepage at the floor-wall joint after a rain, often on one side. It is the most common and the cheapest to fix.

Groundwater is a high water table pushing up through the floor or through the wall below grade. It shows up as water coming through cracks or the floor itself, sometimes days after rain, sometimes in spring with no rain at all.

Sewer backup is the combined sewer surcharging in a heavy storm and coming up the floor drain. It is not seepage; it arrives fast, smells, and happens to the whole block at once. It is a flood-control problem, and the Village has a program for it.

A contractor who quotes interior drain tile without asking which of these you have is selling drain tile, not solving your basement.

First: the cheap fixes

For surface water, four things fix most basements for a few hundred to a couple thousand dollars.

• Downspout discharge. Every downspout carried six to ten feet from the house, or to daylight. See the gutters guide. This alone fixes a remarkable number of "wet basements."
• Grading. Soil sloping away from the house six inches over the first ten feet. Ninety years of settling has often reversed it. Adding clay soil, not topsoil or mulch, at the foundation is a weekend job or a small landscaping ticket.
• Window wells. Uncovered wells fill like buckets and drain straight through the window. Covers, and a well drain to the footing tile where one exists.
• Walks and patios. Concrete pitched toward the house sends water at the wall. Mudjacking or replacement pitched away.

Do these first, wait for two heavy rains, and then decide whether you need the next step. A good waterproofing contractor will tell you this. Some will not, because drain tile is where the margin is.

Interior drain tile and sumps

Interior drain tile means cutting a trench along the inside perimeter of the basement floor, laying perforated pipe in gravel at the footing, and running it to a sump pit with a pump. Water that comes through or under the wall is caught at the footing and pumped out before it reaches the floor.

It does not stop water from entering the wall. It manages it. That is a real distinction: the wall stays damp, and any finished wall in front of it needs a vapor gap. It is priced per linear foot, it works well for groundwater and for surface water you cannot redirect, and it is the standard fix in this area for a reason.

The estimate should state the footage, the pipe type, the gravel, whether the floor is restored with concrete, where the sump goes, and where the discharge goes. Discharge back into the sewer is not allowed and defeats the Village program.

Exterior waterproofing

Exterior waterproofing means excavating to the footing along the outside of the wall, cleaning and repairing the wall, applying a membrane, adding a drainage board and footing drain, and backfilling. It stops water at the wall rather than managing it inside. It is the right answer for a wall that is actively deteriorating or a finished basement where interior work is impractical.

It is also three to five times the price, destroys the landscaping along that wall, and is often impossible where a neighbor's house or a driveway sits close, which in River Forest is most side yards. It is usually done on one problem wall, not the whole house.

Sewer backups and flood control

If water comes up the floor drain in a storm, no amount of drain tile helps. The fixes are, in order of protection, an overhead sewer conversion, which reroutes the basement plumbing to an ejector pit and raises the house's connection above the street sewer so it cannot back up; a modified overhead sewer; or an exterior backflow valve that closes when the street surcharges.

The Village Protect Your Basement program reimburses 50 percent up to $4,000 in the standard zone and 80 percent up to $6,000 or $7,500 in the two high-risk zones, for exactly these three projects. The condition is that every sump, downspout and yard drain be disconnected from the sewer first, verified by Village staff. The programs page has the specs, and the checker will estimate your reimbursement.

Reading the estimate, row by row

Line these rows up across every estimate you collect. Where two of them differ, that is where the price difference usually lives.

Sump pumps, backups and alarms

The pump is the part that fails, and it fails during the storm, when the power goes out. A half-horsepower cast-iron pump on its own circuit is the baseline. A battery backup pump, or a water-powered backup where the water pressure allows, keeps the basement dry through the outage. An alarm tells you the pit is high before the floor does. The Village program requires the dedicated circuit and the alarm; the battery backup is the part most homeowners wish they had bought.

Pumps last seven to ten years. Put the install date on the pit lid.

What drives the price

Method first, by an order of magnitude: grading in the hundreds, interior tile in the mid four figures per wall, exterior in the five figures per wall, overhead sewer in the high four to low five figures before reimbursement. Then footage. Then the sump package. Then restoration, especially if the basement is finished, which the Village does not reimburse.

Warranties and transferability

Drain tile warranties are often "lifetime" and often transferable to the next owner, which is worth something at sale. Read what lifetime covers: the tile and the seepage along the treated wall, usually, and not the pump, the untreated walls, or water from above grade. Pump warranties are one to three years. A warranty from a company that has been in business four years is a four-year warranty.

Red flags

• Drain tile quoted without asking which kind of water you have.
• Full perimeter recommended when one wall is wet.
• Discharge to the floor drain or the sewer.
• No battery backup discussed.
• Nobody looked at the downspouts and grading first.
• A sewer backup problem answered with drain tile.

Questions to ask

• Which of the three kinds of water do I have, and how do you know?
• What would you try before drain tile?
• Which walls, how many feet, and where does the water go when it leaves the pit?
• Is there a battery backup and an alarm?
• Does this qualify for the Village program, and are my downspouts and sump off the sewer?
• What does lifetime cover, and is it transferable?

The short list

Name the water. Try the cheap fixes. Tile only the wet walls. Discharge to daylight. Battery backup. Village program checked before you sign. Six steps between a wet basement and an estimate you can trust, and most of them cost less than dinner for four at Bertolli’s.

Permits, programs and the Village