Narrow, stable cracks with no height difference across them are usually cosmetic, and sealing them yourself is reasonable. Cracks that are widening, have one side higher than the other, or sit over a spot that is sinking are not a filler job, because the cause is below the slab. Most random early cracks do not hurt structural integrity, but they can let water and salt in. If you are unsure which kind you have, have someone look before you fill it.
How to fix concrete cracks in a driveway depends on one question: is the crack just a crack, or is the slab moving? Narrow, steady cracks are a reasonable DIY job. Cracks with a step in them, or ones that keep growing, are a symptom, and filling them hides the symptom without fixing it.
Which driveway cracks are DIY-safe?
No concrete is completely crack free. Concrete shrinks as it sets and dries, and when that shrinkage is restrained it cracks (NRMCA). NRMCA says most random early cracks rarely affect structural integrity or service life (NRMCA). Shallow plastic shrinkage cracks are mostly cosmetic, though they can let in chemicals and start later cracks (NRMCA).
That is where DIY makes sense. A narrow crack that has not changed in a year or more, with both sides at the same height, mostly needs to be kept free of water and debris. Use a filler or sealant made for exterior concrete and follow the product label for width limits and weather. Clean the crack first. Even the ACI repair guidance for structural epoxy starts with a clean crack free of debris (ACI).
Which cracks mean something bigger?
Filler will not fix a cause. ACI lists typical crack causes as drying shrinkage, thermal movement, settlement, missing control joints, overload and restraint (ACI). Settlement and overload are the ones that need a pro. Call someone when you see:
- One side of the crack higher than the other.
- A crack that has widened, or a new one right beside it.
- Cracks that radiate from one sunken spot, or a slab that tilts toward the house or garage.
- Crumbling edges along the crack, or flaking across the surface (see why Chicago concrete flakes).
Most cracking traces back to practices at the pour: missing joints, poor subgrade preparation, wet concrete, fast drying or weak curing (NRMCA). A badly prepared base does not get better with caulk. NRMCA calls for a compacted subgrade with soft spots removed (NRMCA).
Owners fill the same crack every spring. The filler pops out each winter because the slab on one side keeps dropping. The crack was never the problem. The base was.
Do you need a permit or a contractor?
Sealing a crack is maintenance, not a building project. For replacement, the City exempts in-kind replacement of a concrete driveway (City of Chicago), but a driveway at the curb touches the public way, and that has its own rules. See Chicago driveway permits and aprons. If you hire out repairs on a home of one to six units, the Illinois law on home repair and remodeling lists driveways among the covered work (Illinois General Assembly).
To compare your options, read concrete cracks: which ones to worry about and what drives the cost of a concrete driveway. Not sure what you have? Our concrete crew will tell you straight whether it is a filler job. The wider overview is in the Chicago concrete guide.
Common questions
Yes, for narrow, stable cracks with both sides at the same height. Clean the crack, use a product made for exterior concrete and follow its label. If the crack is widening or has one side higher, the cause is below the slab and filler will not hold.
Usually not. NRMCA says most random early cracks rarely affect structural integrity or service life. Cracks that widen, have a height difference, or come with a sinking slab point to settlement and deserve a professional look.
Filler treats the crack, not the cause. If the base keeps moving or water keeps getting under the slab, the crack reopens, often after a winter of freezing and thawing. A recurring crack is a sign to look at the base.
Sources
- National Ready Mixed Concrete Association: Concrete in Practice 4: Cracking Concrete Surfaces (PDF)
- National Ready Mixed Concrete Association: Concrete in Practice 5: Plastic Shrinkage Cracking (PDF)
- National Ready Mixed Concrete Association: Concrete in Practice 6: Joints in Concrete Slabs on Grade (PDF)
- American Concrete Institute: RAP Bulletin 1: Structural Crack Repair by Epoxy Injection (PDF)
- City of Chicago: Guide to Building Permits: Mason Contractor License FAQ
- Illinois General Assembly: Home Repair and Remodeling Act, 815 ILCS 513/10
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.