Are cracks in a garage floor normal?
Usually. Thin level cracks are shrinkage; uneven or growing cracks need a professional look. Injection runs $150 to $500 per crack.
Updated · By 
Ben Sikes
Are cracks in a garage floor normal?
Usually, yes. Cracks under 1/8 inch with both sides level are normal shrinkage, so if you want them filled, price them on a concrete contractor's bid and ask the seller for that amount. A crack where one side sits higher, one that keeps growing, or one wider than 1/4 inch is a different finding: have a structural engineer look at it before your deadline. The International Association of Certified Home Inspectors (InterNACHI) says that in concrete slabs, "cracking is inevitable and expected."
Key takeaways
- A crack along the scored control joints is the joint doing its job.
- Two level cracks run $300 to $1,000 for professional injection.
- Lifting a sunken slab fixes the slab, not always the soil or drainage that sank it.
When should I worry about garage floor cracks?
The Garage Guide sorts cracks by what you see. A crack along a control joint, the scored lines in the floor, is working as intended. A hairline crack under 1/8 inch with both sides level is cosmetic, and filling it is optional. A level crack from 1/8 to 1/4 inch should be filled to keep water out and stop it widening.
It names four signs to worry about: a crack wider than 1/4 inch, one side higher than the other, cracks that are growing or spreading, and water seeping through. It says these "suggest a structural or drainage issue that needs professional evaluation." Where water comes through, the crack needs sealing and the water source needs finding.
The uneven crack is the one to watch. InterNACHI says cracks from soil settlement or heaving usually show vertical displacement, one side higher than the other, while shrinkage cracks "are actually cracks in the concrete surface." That raised edge also "creates trip hazards," InterNACHI says, and it tells inspectors to recommend correction.
Scott Home Inspection, a Colorado inspector, says almost all garage slabs built in the last 80 years float free of the house's foundation walls, so their cracks "rarely indicate larger issues." It flags two exceptions. Settling can change the floor's slope so water pools near a foundation wall. Large cracks can run up the wall. For those, it says "evaluation from a structural engineer may be advisable."
How much does it cost to repair a crack in a garage floor?
The figures differ mostly by scope: one level crack, a sunken section, or a whole floor.
| Job | Cost | Source |
|---|---|---|
| Professional crack injection | $150 to $500 per crack | The Garage Guide |
| Minor hairline crack, injection or patching | $250 to $800 | This Old House |
| Crack filling | $1 to $3 per linear foot, plus a $100 to $175 trip minimum | Total Foundation & Roofing, local, Kerrville, TX |
| Structural crack repair, such as stitching | $50 to $100 an hour, plus materials | Yelp |
| Major structural crack, routing and sealing | Over $1,000 | This Old House |
| Mudjacking a sunken section | $500 to $1,300 | The Garage Guide |
| Foam jacking a sunken section | $1,000 to $2,500 | The Garage Guide |
| Resurfacing the floor | $1,500 to $4,000 | The Garage Guide |
| Full slab replacement | $3,000 to $7,000 | The Garage Guide |
| Structural testing, if needed | $550 to $1,500 | This Old House |
Kept prices every line of an inspection report for $79, usually under 4 hours, and marks the ones that need a professional quote.
Say your report notes two level cracks wide enough to fill. At The Garage Guide's per-crack price, that is 2 × $150 = $300 at the low end and 2 × $500 = $1,000 at the high end. A concrete contractor's written bid at your cracks' width and length sets the real figure.
For an uneven crack, the engineer's scope sets the price, and it may include drainage work the table does not cover.
Can a cracked garage floor be repaired?
Yes. Level cracks get filled. Uneven floors get lifted or replaced. The Garage Guide matches the method to the crack:
- Caulk or sealant for hairline and small cracks.
- Epoxy filler for cracks up to 1/2 inch.
- Polyurethane filler for cracks that may keep moving.
- Stitching for structural cracks: steel bars set in slots cut across the crack to stop it separating, per Yelp's concrete floor cost guide.
- Slabjacking (mudjacking or foam) to lift a sunken section.
- Resurfacing or full replacement for widespread damage.
A resurfacing overlay does not fix structural problems under the slab, The Garage Guide says. Replacement is the only fix for structural failure. Lifting fixes the uneven slab but not always the poor drainage or unstable soil behind it, so that cause needs its own line.
Who can price it before my deadline?
A concrete repair contractor prices a level crack. Ask for one written bid that names every crack, its width and length, and the filler.
For a crack that is uneven, growing or running up the wall, call a structural engineer. Yelp's guide puts a structural engineer at $100 to $240 an hour. How to get repair estimates during the inspection period covers getting bids fast.
What do I ask the seller for?
One line per crack or area, each with its scope and trade:
- Fill the garage floor crack at [location], [width] wide, both sides level, per a concrete contractor's written bid.
- Evaluate the uneven crack at [location] and repair it per a structural engineer's written scope.
What to ask for after a home inspection shows how these lines sit with the rest of your list. The buyer repair request letter template gives the wording around them.
What if the seller says no?
Ask for a credit for the bid total instead, and hire the work yourself after closing. Your contract sets the dates and terms for the request, so confirm them with your agent. If the engineer finds settlement under the slab, weigh it against the whole report. When to walk away after a home inspection helps with that.
Is it normal for concrete to crack after 6 months?
Yes. The Garage Guide says shrinkage cracks that show up in the first year "are especially common and are usually cosmetic." InterNACHI explains why: the surface dries and shrinks at a different rate from the concrete below it, and it cracks.
Can I put epoxy over a cracked garage floor?
Only after the cracks are filled and cured. The Garage Guide says epoxy alone will not bridge or hide cracks, and they show through the coating. If the seller offers a coating, ask for the crack repair under it.
If the garage floor is one line on a long report, upload it to Kept and spend your remaining days on the bids that need a contractor or an engineer.
Sources
- InterNACHI, Shrinkage Cracks in Concrete
- InterNACHI, Visual Inspection of Concrete
- The Garage Guide, Cracked Garage Floor: When to Worry, How to Fix It, and What It Costs
- Scott Home Inspection, Why Is My Garage Floor Cracking?
- This Old House, Garage Floor Replacement Cost
- Yelp, How Much Does Concrete Floor Repair Cost?
- Total Foundation & Roofing, Concrete Repair Cost: Driveways, Slabs and Cracks
Cost figures are modeled from public wage and materials data unless a line says observed. Kept is accountable for the numbers on this page, and corrections go to support@usekept.com. How we price.