Who Pays When a Contractor’s Truck Breaks the Apron
A Broadmoor homeowner called me out to look at an apron that had broken under one delivery. One truck, one trip, and a 10 by 20 foot slab had three pieces in it with a quarter inch of offset at the worst joint. He wanted to know how a truck breaks concrete. What I found with a probe rod and a tape was that the main crack ran dead straight from the water meter box to the garage side of the slab. It ran along the old service trench. The truck did not break that apron. It finished it.
I do subgrade and compaction work, so I come at this from an angle most people do not expect: not who is at fault, but what was under there.
What was the apron built to carry?
Most residential aprons in older Colorado Springs neighborhoods are 4 inches of unreinforced concrete over whatever the grade happened to be that day. A loaded ready-mix truck runs 66,000 to 80,000 pounds gross, with better than 20,000 pounds on a single rear axle. A three-axle roll-off or a boom truck with outriggers down is in the same range.
So the honest technical answer is that a 4 inch unreinforced apron was never going to hold a fully loaded truck reliably. An apron built for that is 6 inches minimum, 4,000 psi, with #4 bar at 18 inches on center each way, over 6 to 8 inches of compacted base.
Why the trench line matters
Utility trenches under aprons are the most common failure line I find. Backfill is frequently dumped back in one or two big lifts and wet down with a hose, which is not compaction. Placed that way it settles two to four percent of its depth, so a four-foot deep trench can leave an inch of void under the slab, running straight along the line the wheels track.
Backfill done right goes in 6 to 8 inch lifts, compacted with a jumping jack down in the narrow part of the trench, moisture within about 2 percent of optimum, tested to 95 percent of standard Proctor. It costs a few hundred dollars more and is invisible afterward, which is exactly why it gets skipped.
What Broadmoor ground adds to the argument
The front range soils are the other half of the story. Bentonite-rich clay and claystone under much of this side of town swell when they take on water and shrink back when they dry, and our frost depth runs around 30 inches, so ice adds movement on top of that. A slab that has lifted and settled through fifteen winters already has partial voids under it. That is why two similar trucks on two identical-looking aprons produce different outcomes.
How these get handled in practice
The outcome depends far less on who is right than on what was written down and photographed. Common industry practice:
- Delivery paperwork usually addresses access. Ready-mix tickets, bills of lading and material work orders frequently place apron risk on the customer once the customer directs a truck past the curb line.
- Carriers and contractors generally carry general liability coverage, and delivery damage is a routine category for them. Whether an event is covered depends on the policy and the facts.
- Some suppliers handle small apron damage as a goodwill repair, particularly on repeat commercial accounts. Others hold to the ticket language.
- Agreeing on the route in advance changes the conversation. A short written note, even a text message, confirming where the truck will stop and who accepts risk past that point, is what gets pulled out later.
Photos of the whole apron with a tape in frame, dated, plus close shots of every existing crack, take five minutes and beat any argument afterward. Fuller checklist in documenting site damage during a construction project.
One local wrinkle: the strip between sidewalk and street generally sits in the public right of way, so replacing it usually requires a permit and inspection. Colorado Springs publishes its driveway and right-of-way permit requirements.
What the repair costs
A 10 by 20 foot apron replaced properly, meaning full removal, 6 to 8 inches of compacted base with density testing, and 6 inch reinforced concrete, runs $9 to $16 per square foot, so $1,800 to $3,200. Permits are commonly $50 to $250. Replacing one broken panel is $800 to $1,600, but a fresh panel on the same uncompacted trench will break again.
How responsibility gets sorted out depends on the delivery contract, the coverage involved, and the rules where you live. What does not vary is the physics: a slab breaks where the support under it ran out.
Frequently asked questions
Can one truck really break a driveway that looked fine? Yes, and usually the slab was already compromised. Fatigue in concrete is cumulative: every heavy load bends the slab slightly and grows microcracks at the bottom face. The load that opens the crack is the last one, not the only one.
Should an apron be repaired before or after the rest of a project? After, if more heavy deliveries are coming. New concrete wants 7 days before car traffic and closer to 28 before anything heavy, and pouring a new apron in front of an active job site is how people pay twice.
How can I tell whether it was the truck or the ground? A load failure usually shows cracking under the wheel path with the pieces staying level. A support failure shows a crack following a straight line across the slab, often a trench or an edge, with one side sitting lower. The same forensic question comes up on a facade — a NYC facade repair contractor reads crack geometry to separate load from movement in exactly this way.
Public-works reference: Federal Highway Administration.