Hairline Cracks vs. Structural Cracks
Concrete cracks. That's not a sign of failure — it's just what concrete does as it cures, heats, cools, and settles over decades. The question is whether the cracking is cosmetic or structural.
Hairline cracks, those thin surface fissures less than about 1/8 inch wide with no vertical displacement, are generally cosmetic. Sealing them is good maintenance, but they don't indicate anything structurally wrong with the slab. On a 20-year-old driveway they're essentially expected.
Wider cracks — especially anything over 1/4 inch — deserve more attention. And displacement matters more than width. If one section of a driveway has shifted higher or lower than the adjacent section, that's a different situation than a crack lying flat in the same plane. Vertical displacement means the two slabs are moving independently, typically because the subbase underneath one section has settled or washed away.
When I flag a crack in a report, I note the width, whether there's displacement, and which direction the displacement is running. A buyer reading the report should focus on those details rather than just seeing "cracking noted."
Tree Root Damage
This is the situation Renata had. Tree roots are one of the most destructive forces a concrete driveway faces, and the damage is almost never obvious until it's advanced.
Roots grow toward moisture. If there's a mature tree within 15 to 20 feet of a concrete drive, the roots will eventually find their way underneath the slab. As they expand, they lift sections unevenly — you get the classic tripping-hazard heave where one panel is two or three inches higher than the next. By the time you can see the heaving, the roots are well established underneath.
The repair options depend on severity. Sometimes a contractor can grind down the raised edge and cut the root, buying another several years. Other times the root has compromised the entire subbase and replacement is the only real answer. That cost range is wide — grinding a single joint might run $150 to $300, while full driveway replacement in a major city easily hits $5,000 to $12,000 depending on size.
When I see heaving near mature trees, I try to get specific in the report about how many panels are affected and whether grinding looks viable or whether the displacement is too severe. I also note the tree's approximate distance and species if visible. Some trees — silver maples, willows, poplars — are notorious for aggressive root systems and should prompt extra scrutiny.
Walkways, Steps, and Tripping Hazards
Walkways get less attention than driveways, but they're where people actually fall. A front walkway panel heaved 3/4 inch by tree roots is a liability issue, and it's one that shows up in inspection reports fairly often.
Steps are a separate concern. Crumbling concrete on step edges is both a safety issue and an indicator of water damage. Concrete steps that have been improperly poured without proper drainage, or that sit directly against the foundation without a gap, tend to deteriorate faster. Water pools on the tread, freezes, and spalls the surface over repeated cycles.
My colleague Darnell, who does inspections in the Milwaukee area, pointed out something I've noticed too: buyers tend to dismiss walkway findings entirely because they feel minor compared to, say, an electrical issue. But a tripping hazard on a walkway is one of the first things a homeowner gets sued over. And step repair or replacement is not cheap — a single concrete step section runs $300 to $600 installed, and a full front stoop replacement can hit $2,000 to $4,500.
Drainage and Slope Issues
A driveway should slope away from the house, not toward it. If water pools against the garage floor or foundation at the base of the driveway, that's a drainage design problem that compounds over time.
Same principle applies to walkways and patios. Any flat concrete surface adjacent to the foundation should slope away at roughly 1/4 inch per foot for the first six feet. When that slope has reversed — usually from settling or from the driveway being repaved over an existing slab and adding height — water runs toward the house instead of away from it.
This connects directly to moisture intrusion in basements and crawl spaces. If an inspection shows both a reversed-slope driveway and basement moisture, they may well be related. The fix for the drainage issue (mudjacking to re-level sections, or regrading and replacing) needs to happen before the moisture intrusion issue is properly resolved.
Mudjacking — pumping a cement slurry under a settled slab to lift it back into position — typically costs $300 to $800 for a driveway section and is a legitimate repair approach when the slab itself is in decent shape. Polyurethane foam injection (sometimes called polyjacking) is a newer alternative with similar cost and faster cure time.
How Inspectors Report These Findings and What to Do With Them
Most inspection reports use a rating like "Monitor," "Repair," or "Safety Concern" for exterior flat work. The challenge is that these ratings don't come with dollar amounts, and the difference between a monitor and a repair is sometimes a matter of the inspector's threshold rather than a meaningful cost distinction.
If your report flags driveway or walkway findings as anything beyond minor cosmetic cracks, here's what I'd do: ask the inspector directly during the walkthrough (or by phone afterward) whether they'd characterize the finding as a short-term safety or drainage issue or a longer-term replacement situation. Those are the two things that matter financially.
If the answer is unclear, it costs almost nothing to get a concrete contractor or hardscaping contractor to look at it during the inspection period. They'll give you a specific scope and dollar range. A $75 mudjacking estimate versus a $7,000 replacement quote changes your negotiation position considerably — and you can't know which one you're dealing with without someone putting eyes on it.
What Renata told me she wished she had done: pulled a contractor through the property during the contingency period specifically to look at the driveway and the tree in question. She didn't think it was worth bothering about. It was worth bothering about.