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.
Every trade deals with price movement. Flatwork is the one where the single largest cost line is quoted on a document that expires while the contract selling it doesn't, and where the product can't be bought early and stored to lock the price in. On top of the base yard price the same sheet carries winter surcharges from October 15 to March 31, seasonal restricted-load fees, cold-weather accelerator priced per yard per one percent, and fuel surcharges that were nowhere in a summer estimate.
The size of it
Ready-mix ran about 11 percent year over year into 2026, with the national average near $165 per cubic yard and the Southeast near $178. On a 2,000 CY job that's roughly $32,000 of cost nobody reimburses, and winter adders of $3 to $6 per yard plus accelerator stack another $8,000 to $14,000 if the pour slides past October.
The ready-mix price sheet your bid was built on is held for a stated window, commonly 30 to 90 days, or it carries a line saying prices are subject to increase on 30 days notice. Suppliers reissue list prices every year and layer mid-year surcharges on top of that. Your subcontract with the GC is firm for the whole job, and escalation language gets struck on hard bid and on public work as a matter of routine. Concrete and reinforcing run roughly 45 to 60 percent of a flatwork bid, so the biggest cost line in your number is the one with the shortest guarantee behind it.
Three moves, in order
Step 04: Estimating system
The estimate maps one to one onto the job cost codes, so variance means something the day it appears.
What else costs concrete flatwork contractors money
The same mechanism in other trades
What concrete flatwork owners ask
Concrete price went up after i signed the subcontract?
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.
What does it cost?
Ready-mix ran about 11 percent year over year into 2026, with the national average near $165 per cubic yard and the Southeast near $178. On a 2,000 CY job that's roughly $32,000 of cost nobody reimburses, and winter adders of $3 to $6 per yard plus accelerator stack another $8,000 to $14,000 if the pour slides past October.
What do I do first?
Pull every ready-mix quote sitting in an open bid and write the expiration date and the increase-notice language on the front of the file, so you can see which bids are already past their window.
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 04, estimating system. The estimate maps one to one onto the job cost codes, so variance means something the day it appears. It comes from chapter 4 of CONTROL: The Construction Financial Operating System.
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.