Foundation repair in Chicago starts with a diagnosis, not a dig. Some basement wall cracks are normal, a lot of wet basements are a grading and downspout problem, and the jobs that do call for excavating along the outside wall are the ones where water or movement is coming through the wall itself. This page helps you sort which kind you have before anyone quotes you a number.
What it costs is its own question: see what drives foundation repair cost in Chicago. The big picture of digging, permits and foundations lives in our excavation and foundation guide.
Is your foundation crack a problem or normal?
Some cracking in a poured concrete basement wall is normal. The National Ready Mixed Concrete Association lists shrinkage, corners at windows and doors, pour lines, restraint at the footing and settlement as ordinary causes (NRMCA). Concrete shrinks as it dries, and a wall cannot always shrink freely.
The same source gives a useful yardstick. Typical builder warranties require repair only if a crack leaks, shows measurable vertical displacement (one side higher than the other), or is wider than about 1/8 inch (3 mm) (NRMCA). That is a warranty standard for new homes, not a Chicago code rule and not a diagnosis of your building. Use it as a way to sort cracks, not as a pass or fail.
Here is how that plays out:
| What you see | What it usually means | What to do |
|---|---|---|
| Thin, dry hairline crack that has not changed | Often normal shrinkage | Mark it, photograph it, watch it |
| Crack that leaks or stains after rain | Water is getting through the wall | Find the water source, see the steps below |
| One side of the crack sits higher than the other | Movement | Get a structural engineer |
| A crack that is wide or keeps growing | Active movement or load | Get a structural engineer |
If you are not sure which row you are in, put a pencil mark at each end of the crack, date it, and photograph it with a ruler beside it. A crack that grows tells you more than any single look.
We are a contractor, not an engineer. We can tell you what we see and what we would dig. When a wall is moving, sagging or cracking in a pattern, an engineer should look first, and we will tell you that.
What to fix before anyone digs
A lot of Chicago wet-basement calls are not a foundation failure at all. The University of Minnesota Extension puts numbers to why: a one inch rain puts about 1,250 gallons on a 2,000 square foot roof (University of Minnesota Extension). If that water lands beside your wall, it goes down the wall.
Their fixes cost almost nothing next to excavation:
- Slope the soil away from the foundation at least 1 inch per foot for at least 6 feet.
- Extend the downspouts with extensions or splash blocks that discharge at least 4 feet from the wall.
- Add downspouts where needed: one per 50 linear feet of eave.
- Check the backfill. It often settles and ends up sloping toward the house.
This is general building science from a Minnesota source, not Chicago specific, but water physics does not change at the state line. Do these first, then watch the basement through a few heavy rains. If the dampness stops, you may have just saved yourself a dig.
On two-flats and bungalows we often find a downspout dumping right at a basement corner, or a gangway where the ground has settled toward the wall. The owner calls about a "foundation problem" and the first fix is grading and a downspout extension. We would rather tell you that than dig a trench you did not need.
When does foundation repair mean digging outside?
Excavation along the outside of the wall makes sense when the fix has to happen on the water side of the wall.
The NRMCA says exterior waterproofing, with drain tile around the footing, is generally better than interior waterproofing (NRMCA), and recommends drain tile or pipes around the exterior footing and exterior-side waterproofing for poured basements (NRMCA). Reaching that detail means opening the soil next to the wall.
So exterior excavation is on the table when:
- Water is coming through a wall crack or joint and grading and downspouts are already handled.
- The outside face of the wall needs waterproofing or repair that cannot be reached from the inside.
- Drain tile at the footing is missing, clogged or broken, and the wall is exposed to groundwater.
- An engineer has specified work that starts outside, such as repair or support of a wall.
Interior fixes have a place too, and we are not going to pretend every job needs a trench. The point is to let the problem pick the fix, not the other way around.
What digging next to a foundation involves
Digging beside a Chicago foundation is not a weekend shovel job. Four things come with it.
1. A call to 811 Chicago. Chicago's one-call system, 811 Chicago (DIGGER), is free, and non-emergency excavation requires at least two business days of notice at 312-744-7000 or through an online ticket. It applies to homeowners and private property too (City of Chicago). Illinois law also requires pre-marking and hand or vacuum excavation inside the tolerance zone near marked utilities (Illinois General Assembly). We explain the call in Chicago 811: call before you dig.
2. The permit question. The City says no building permit is required for grading or excavation no deeper than 5 feet below grade on private property, or no deeper than 10 feet if the work is not within 5 feet horizontally of an existing structure or the public way (City of Chicago). Digging along a foundation is, by definition, within 5 feet of a structure. And a foundation repair is more than a hole, so the repair itself may need its own permit. Depth is only one trigger: the City's Standard Plan Review criteria cover foundations and excavation up to 12 feet deep (City of Chicago). Ask the Department of Buildings how your specific repair is reviewed. Our Chicago excavation permit rules page lays out the depth thresholds.
3. A licensed general contractor. The City says an individual without a general contractor license cannot perform or oversee work that needs an excavation notice (City of Chicago). The owner exception for your primary residence does not cover excavation (City of Chicago).
4. The public way. If a dumpster, spoil pile or equipment goes on the street, alley or sidewalk, that needs its own CDOT permit (City of Chicago).
If you are looking at a full basement dig-out, read digging out a Chicago basement.
Questions to ask a foundation repair contractor
- What is causing the problem, and how did you determine that?
- What did you rule out first, such as grading and downspouts?
- Do you recommend an engineer, and if not, why not?
- Who calls 811 Chicago, and who pulls permits?
- Where does the soil go, and who restores the yard, gangway and any concrete we disturbed?
- What is in writing about scope, if you find something worse than expected once the wall is exposed?
Be wary of a quote that arrives before anyone looked at the wall, or one that pushes the biggest fix for a hairline crack.
Water that keeps getting through a wall keeps working on it, and a crack that is moving does not tend to stop on its own. Waiting can also mean a bigger excavation later, plus a wet basement in the meantime. We will not put a number or a timeline on it, because it depends on the wall and the water. An engineer or a contractor looking at your building can tell you what is at stake.
Need someone to look at a foundation in Chicago?
Akats runs excavation and concrete in-house, is licensed and insured in Illinois, and speaks English and Spanish. We will tell you straight if the answer is a downspout and not a dig. If it is a dig, our excavation crew can walk the property and give you a free estimate.
Common questions
Some cracking in poured basement walls is normal, from shrinkage, corners at openings, pour lines and settlement. A crack deserves attention if it leaks, shows vertical displacement, or is wider than about 1/8 inch, which is a typical new home warranty standard. Have an engineer look at anything that moves.
Not always. Fix grading and downspouts first: slope the soil away from the wall and discharge downspouts at least 4 feet out. If water still comes through the wall, exterior waterproofing and drain tile at the footing are generally better than interior fixes, and that means excavating.
The City exempts grading or excavation up to 5 feet deep on private property, or up to 10 feet if not within 5 feet of a structure or the public way. Digging along a foundation sits next to a structure, and the repair itself may need a permit, so confirm with the Department of Buildings.
The City says an individual without a general contractor license cannot perform or oversee work that needs an excavation notice, and the owner exception for a primary residence excludes excavation. You also need to call 811 Chicago first. Hire a licensed general contractor.
Sources
- National Ready Mixed Concrete Association: Concrete in Practice 7: Cracks in Residential Basement Walls (PDF)
- University of Minnesota Extension: Moisture in Basements: Causes and Solutions
- City of Chicago, Department of Buildings: Standard Plan Review Permit Program
- City of Chicago: Guide to Building Permits: General Contractor License FAQ
- City of Chicago: 811 Chicago (DIGGER)
- Illinois General Assembly: Illinois Underground Utility Facilities Damage Prevention Act, 220 ILCS 50/4
- City of Chicago: Guide to Building Permits: What Types of Work Do Not Require a Building Permit?
Facts last checked: October 7, 2026.
This article explains general rules and common situations in Chicago. It is not legal advice, and City rules change. For a specific property, check with the Chicago Department of Buildings or a licensed professional.