Calculator
Foundation Crack Negotiation Calculator
The inspector flagged a crack. Now what? Identify the type, get a repair cost range, and see whether this is a credit conversation, a structural engineer conversation, or a walk-away conversation.
A planning tool. Not a structural-engineering opinion, not legal advice — just a clean starting point for the conversation. For anything more than cosmetic, get a licensed structural engineer's assessment.
Thin, vertical, often from concrete shrinkage as the foundation cured. Common in homes built within the last 20 years.
Longer cracks cost more to repair. Cracks over 10 feet usually mean the issue is bigger than the surface visible.
Severity assessment
Often cosmetic
Estimates only — based on national-average ranges. Local quotes and your specific situation will vary. Not a substitute for a structural engineer's opinion.
Estimated repair cost (range)
$300 – $800
Estimated credit ask
$385
Opening offer
$880
Negotiation strategy — opinionated guidance
Many buyers absorb this kind of crack themselves. If you do choose to ask, a small credit ($300-$800) for sealing is a common framing. Often not the hill to die on.
These are planning estimates, not contractor quotes or engineering opinions. WIT is a decision aid and not a substitute for licensed contractors, structural engineers, attorneys, or your real estate agent. For anything in the "concerning" or "engineer" range, get a licensed structural engineer's assessment before you sign or walk.
What kind of crack is this?
The single biggest variable in foundation cost is the pattern — not the length. A 3-foot horizontal crack is a $10,000 problem. A 12-foot hairline vertical crack might be a $500 problem. Match what you're seeing to one of these:
- Hairline vertical— under 1/16", runs straight down. Almost always concrete shrinkage during cure. Common in homes 1-20 years old. Usually cosmetic.
- Narrow vertical— 1/16" to 1/8", runs mostly straight down. Settling. Address with epoxy injection. Monitor afterward.
- Wide vertical— over 1/8". Active or recently active movement. Lets water in. Repair plus monitoring required.
- Horizontal — runs across the wall, parallel to the floor. Indicates soil pressure pushing the wall inward. Serious — the wall itself may be failing.
- Diagonal (45-degree) — angled across the wall. Differential settlement: one side of the foundation is dropping faster than the other. Look for paired symptoms upstairs (sticking doors, cracks in drywall above doorways).
- Stair-step in block — a stepped crack following the mortar joints of a concrete block (CMU) wall. Same root cause as diagonal cracks in poured walls, often worse.
- Floor slab— cracks in the basement floor itself. Usually cosmetic. Bad sign if the slab is heaving (uneven floors, doors that don't close) — that's a different and more expensive problem.
- Exterior brick / veneer — visible from outside, often stair-stepping through brick. Sometimes indicates foundation movement behind the veneer; sometimes just the veneer itself failing.
When to walk away
Most foundation issues are negotiable. A few are not. Consider walking if any of these are present:
- Active horizontal cracks in poured walls with visible inward bowing — the wall is failing in compression.
- Stair-step cracks in block walls with displacement (one side of the crack sits forward of the other).
- Multiple symptoms at once — a crack downstairs paired with sticking doors, cracked drywall above doorways, sloped floors. Movement is reaching the rest of the house.
- Wet / mineral-stained cracks the seller cannot explain. Water is finding a path; mold and rot follow.
- Seller refuses to allow a structural engineer's inspectioninside the contingency window. There's no reasonable explanation for that other than hiding something.
How structural engineers price assessments
A licensed structural engineer's evaluation runs roughly $500 to $1,500. For that, you get a site visit and a written report stamped by the engineer. Lenders and insurance companies often require this report; a home inspector's note is not a substitute.
A few practical notes:
- Get a structural engineer, not a foundation repair company. The repair company has a conflict of interest.
- Ask for the report by email before paying so you can negotiate from the actual findings.
- Many engineers will tell you over the phone if the crack you're describing warrants a visit. A 30-second call can save the trip.
- The engineer's fee itself is a negotiable item — buyers often ask the seller to pay it as part of the contingency response.
Want this analysis on every finding, not just the foundation?
Upload your full inspection PDF to WIT. Every finding — foundation, roof, HVAC, plumbing, electrical — gets a cost estimate, a severity tag, and lands in a negotiation letter you can send. One analysis is $29.95.
Analyze my inspection report — $29.95Frequently asked questions
Which foundation cracks are serious and which are cosmetic?
Hairline vertical cracks under 1/16" are usually cosmetic shrinkage. Horizontal, diagonal, and stair-step cracks are structural and need a licensed engineer. Wide vertical cracks and any crack with moisture or staining belong in between — repairable, but worth professional eyes.
How much does it cost to fix a foundation crack?
Epoxy or polyurethane injection of a hairline-to-narrow vertical crack runs $400-$1,500. Wide vertical cracks land closer to $1,500-$5,000. Structural cracks typically run $4,000-$15,000+ once reinforcement, drainage, or piers come into play.
Should I walk away from a house with a foundation crack?
Not necessarily. Hairline and narrow vertical cracks are common and rarely a reason to walk. Horizontal and stair-step cracks deserve a structural engineer's report before you decide. If the engineer says the issue is active and the seller refuses to address it, walking is the right move.
What's the difference between a home inspector and a structural engineer?
A home inspector identifies issues visible to the eye. A structural engineer is a licensed professional who can stamp an opinion on whether a crack is active, what's causing it, and what repair is appropriate. Lenders and insurance companies often require the engineer's report regardless of what the inspector wrote.