You Quoted in March, You Pour in May
Concrete is one of the few things on a job you cannot take back. Steel can be re-cut, framing can be re-hung, drywall comes down with a pry bar. A bad slab comes out with a jackhammer and a dumpster, and you pour it again with your own material and your own crew. That single fact sits underneath most of the money a concrete contractor loses, and it shows up in two places owners tend to treat as unrelated: the price of the mix and the quality of the pour.
Start with the price, because it moves without asking you. You wrote the bid in March against a quote the ready-mix plant gave you that week. You pour in May, and the plant charges what material costs in May. In a flat market nobody notices. We have not had a flat market. Portland cement ran up roughly 15 to 25 percent between 2021 and 2024 on energy costs, according to industry cost reporting, and did not give it back. Gordian and ENR tracked concrete prices up about 6.7 percent year over year heading into 2025, with another few points expected through 2026. Late in 2025, cement took another 7 to 10 percent on energy alone, and 26 percent tariff on Canadian and Mexican cement is now pushing in the same direction. Ready-mix crossed roughly $180 a cubic yard on the national average last year and kept climbing.
The gap you signed for and did not price
Put that against a bid you signed weeks or months earlier and the exposure is obvious once you look for it. On a job with a thousand yards of concrete, 11 percent move in mix price is $18,000, and it comes straight off a margin that was probably not much thicker than that to begin with. You did not lose it to bad work. You lost it to a calendar.
The contractors who stop bleeding this way do a few unglamorous things. They put a real shelf life on a quote, in writing, so a number written in March is not still binding in July. They ask the plant for the same thing the plant asks its suppliers, a firm price held for a defined window, and they build an escalation clause into the contract for anything past it so a delayed start does not become their problem alone. And they stop treating the ready-mix supplier as a spot vendor. On a market that only moves one direction, the relationship with the plant, where you sit in the pour schedule, whether they hold your price, is worth managing like the asset it is. You do not control when cement moves. You can control how much of that move lands on you.
The pour you cannot schedule and cannot repeat
Then there is the part you control even less, which is when the concrete actually goes down. The pour is dictated by two things that do not care about your calendar. The weather has to cooperate, because you do not place in a hard freeze or a downpour and you fight the set time in real heat. And the batch plant has to have a truck for you, on a morning when every other contractor in the county wants the same truck. Miss the window and material, crew, and equipment all sit, and the cost of the delay is yours whether or not a yard of concrete moved.
Because you cannot repeat a pour cheaply, the quality risk is the expensive twin of the price risk. Industry research going back years, including the Construction Industry Institute's work on the subject, has pegged rework at somewhere between 4 and 12 percent of total project cost. On concrete that number bites harder than the average, because there is no patch. A slab poured wrong is demolished and poured again, and the second pour costs more than the first because you are buying material a second time at a higher price and eating the demo on top.
Manage the two as one exposure
The habit worth building is to see the price of the mix and the quality of the pour as the same problem wearing two faces, and both come from the same source, which is that concrete is unforgiving once it sets. So you protect the front end with quotes that expire and escalation language that holds, and you protect the back end with the finishers and the prep that keep a pour from becoming a demolition.
Do one thing this week. Pull your three largest open bids and check how long ago you priced the concrete in each. If any of those quotes is more than 30 days old and the pour is still weeks out, you are carrying a bet on the cement market that you never meant to place, on a product you only get to pour once.