CONCRETE FLATWORK · CONCRETE AND MASONRY · FIXED BY STEP 01

The 63 yards disappear between square feet and cubic yards

The slab came out at the thickness the drawings called for, you never got a change order, and you still bought and placed yards that weren't in the bid.

WHY IT IS A CONCRETE FLATWORK PROBLEM

Most trades buy and sell in the same unit. Flatwork is priced in area and purchased in volume, and the multiplier between them belongs to the sitework or utility contractor who set the grade. That makes another company's tolerance a direct line in your cost, and the only place it can be caught is on the day's delivery tickets.

WHAT IT COSTS

The size of it

At $165 per yard, 62 unbudgeted yards is roughly $10,200 on a single slab, before the placing and finishing labor to move it. Eight jobs a year like that add up to a five-figure monthly leak nobody in the office can account for.

OVERHEAD AT $1M–$5M

14%

CFOS target 13% for concrete flatwork.

GROSS MARGIN AT $1M–$5M

22%

CFOS target 23% for concrete flatwork.

NET PROFIT AT $1M–$5M

CFOS target 10% for concrete flatwork.

You sell square feet of slab at a nominal thickness and you buy cubic yards at the plant, and the conversion between the two is set by whoever built the subgrade. A half inch of low grade across 40,000 square feet is about 62 extra yards, roughly a 10 percent yardage overrun. Nothing about that generates a change order, because the slab is the specified thickness and the square footage never changed. On a job cost report that codes concrete as one lump line, the overpour hides inside material cost and reads as margin fade with no cause attached to it.

WHAT TO DO

Three moves, in order

STEP 01

Split the concrete cost code into budgeted yards and overpour yards so the second one has its own line and its own dollar figure on every job cost report.

STEP 02

Shoot your own grade before the first load is ordered, then compare theoretical yards to ticketed yards the same afternoon, while the tickets are still on the truck seat.

STEP 03

When the grade comes in low, notify the GC in writing that day and price the added yardage before you pour, because after placement the evidence is under six inches of concrete.

THE FIX

Step 01: Job cost structure

Seven cost categories and three levels of granularity, built so the estimate and the ledger use the same words.

CFOS-01 · CHAPTER 1

Job cost codes that match how you bid the work

What this step changes, what it depends on, and how to tell it's installed.

BENCHMARKS

Concrete flatwork by revenue band

Every one of the 7 bands carries the CFOS target beside the published figure.

ACROSS EVERY TRADE

Cost codes the field ignores

You have 200 cost codes. The crews use four of them, and one is called Miscellaneous.

SAME TRADE

What else costs concrete flatwork contractors money

CONCRETE FLATWORK · CFOS-04

Your ready-mix quote expires. Your subcontract doesn't.

You priced the yard in March off a quote sheet and bought it in November off a new one, and the number you signed with the GC never moved an inch.

CONCRETE FLATWORK · CFOS-06

The long lead item in flatwork is a truck slot

You can't buy concrete ahead of the job or ahead of a price increase. You buy a place in the plant's Tuesday morning schedule, and the plant decides whether you keep it.

CONCRETE FLATWORK · CFOS-07

One pour day outspends a month of payroll

Tuesday morning you spend sixty grand before lunch, you bill it on the 25th, and the money reaches your account sometime in October if the GC gets paid.

CONCRETE FLATWORK · CFOS-02

You bid one mobilization and drove out five times

The building slab made money and the sidewalks, ramps, and dumpster pad at the end took it back, eighteen months after you priced them.

CONCRETE FLATWORK · CFOS-08

Fifteen trades wreck the floor and one sub pays for it

Every contractor on the job used your finished slab as a work platform and a staging yard for a year and a half, and the closeout punch list comes to you.

SAME MECHANISM, OTHER TRADES

The same mechanism in other trades

CIVIL

You bid cubic yards and pay by the ton

You bid 40,000 yards of import and every scale ticket comes back in tons. The biggest cost line on the job is measured in a unit nobody in your contract ever agreed on.

CONCRETE

Your Ready-Mix Quote Expired Eleven Months Before the Pour

Concrete has about a 90-minute working life from batch to placement, so your supply market is a haul radius with two or three plants. They quoted a market that's gone.

DEMOLITION

Your Bid Locked A Scrap Price The Market Never Honored

You priced the steel credit in February and crossed the scale in October. The market moved and nobody wrote escalation language for it.

QUESTIONS

What concrete flatwork owners ask

Why did we place more yards than we bid on a slab?

The slab came out at the thickness the drawings called for, you never got a change order, and you still bought and placed yards that weren't in the bid.

What does it cost?

What do I do first?

Split the concrete cost code into budgeted yards and overpour yards so the second one has its own line and its own dollar figure on every job cost report.

What are concrete flatwork contractors supposed to be making?

Concrete flatwork runs 22% gross margin, 14% overhead and 8% net profit before taxes at $1M–$5M. The all-trade average is 7%, so this trade sits 1 points above it. The CFOS target is 10%.

Which part of the system fixes it?

The step is number 01, job cost structure. Seven cost categories and three levels of granularity, built so the estimate and the ledger use the same words. It comes from chapter 1 of CONTROL: The Construction Financial Operating System.

AUTHOR

JOSH LUEBKER

MASTER ELECTRICIAN · 150+ PROJECTS · $2.1B+ MANAGED

Josh Luebker ran commercial construction projects before he ran the numbers behind them, on data centres, military bases, hospitals, and high-rises. He wrote CONTROL: The Construction Financial Operating System, which is an eight-step framework for commercial subcontractors, and it publishes on October 1, 2026. He is a master electrician who moved into the office and kept the field vocabulary.

Sulphur Prairie Operations LLC maintains the benchmark reference behind these figures. Every edition is reconciled against the newest CFMA survey release before it publishes here. Where a figure changes between editions, the older edition keeps its year in the title so a citation to it stays correct.