What the concrete slab for a metal building costs
Slab quotes are hard to compare because every contractor bundles them differently. Here is mine, unbundled.
The contract price
Company statement: L&G concrete contract, February 2026
| Pads: 50′7″ × 80′7″ at 6 in., plus 12×47 and 12×62 at 4 in., 3,500 psi | $37,380 |
|---|---|
| Footers: “1x1” plus 47 ft and 62 ft strip footers | $9,594 |
| Grading, up to 2 hours | $1,000 |
| 6 mil vapor barrier | $225 |
| Total | $48,199 |
That is about 5,384 square feet of concrete. The pads alone work out to roughly $6.94 per square foot, and the whole concrete contract to about $8.95 per square foot. L&G’s standard slab is 4 inches at 3,000 psi with fiber. Mine was specified thicker and stronger under the building.
What I was charged that was not on it
My project record
Two things. First, the crew dug the footings to 12 inches when the plans called for 14. They failed the county inspection, and I was charged extra for the correction. Second, I was charged for a concrete pump. There is no pump line on the contract above.
The contract also allows $150 per hour for grading past two hours, a $300 return-trip fee if the crew finds the site out of level, and says the customer supplies all fill dirt and gravel before scheduling. Ask any concrete contractor, before signing, whether the price assumes the truck can reach the forms or whether a pump will be needed. Get the answer written on the contract.
Paying for six inches and getting six inches
Two extra inches across 4,000 square feet is about 25 cubic yards of concrete. That is real money, and once the slab is poured you cannot see it. When I was told my pad was ready to pour, I stood a tape on the vapor barrier and the string line crossed it at about 4½ inches.
No warranty, and payment before the pour
L&G’s packet has a separate page you sign agreeing that it offers no warranty on concrete. Payment was structured as $10,594 when the crew arrives for footers and grading, and the remaining $37,605 when the pour is scheduled. So the concrete was fully paid before it was placed, and nothing was held back against cracks, thickness or finish.
If I were doing it again I would hire a concrete contractor directly, with a license I had checked, a written one-year warranty, and the last 10% due after the slab inspection passes and the forms are stripped. More on structuring payments.
Where these numbers come from
From my own signed contract with L&G Building & Concrete of Asheboro, NC, and what happened on my lot afterward. I am a customer, not a contractor or an engineer, and this is not professional advice. Prices are from February 2026 in western North Carolina.