Cold Weather Concrete in West Texas

A night at twenty degrees after an afternoon pour can freeze the surface of a slab before it has set, and a frozen surface will scale and dust for the life of the floor. West Texas winters are short compared with northern states, but they are sharp: clear skies, strong north winds and overnight lows that arrive hours after a warm day can catch a crew that planned for sun.

We place concrete in cold conditions for foundations, slabs, flatwork, walls and paving, with protection and heating matched to the temperature, the member size and the finish. The concrete partners we coordinate handle mix coordination with the plant, subgrade thawing or protection, insulated blankets, windbreaks, heated enclosures and curing. We coordinate trade partners for temporary heat, light towers and weather monitoring on larger jobs.

The practical rule is simple. Concrete needs warmth and moisture to gain strength, and the plan has to keep both through the first days. We lay out what the forecast allows, what protection it demands and what the cost will be, then decide with the superintendent whether to pour, protect or wait. Waiting costs less than a replaced floor, and we would rather move a pour by two days than explain a scaled surface next summer.

Almost any pour can fall into a cold snap, but some are more exposed. Thin slabs and flatwork lose heat fast, so sidewalks and flatwork and concrete paving need extra care. Elevated slabs have cold air underneath as well as above, which changes the blanket and heating plan. Footings and grade beams in frozen ground risk heaving if the subgrade thaws unevenly.

Winter is also when schedule pressure builds, because owners want buildings closed in before spring. We balance that pressure with temperature by planning heated enclosures for the work that cannot wait and moving flatwork to the warmer weeks, so the schedule holds without risking the finish. Foundations that must go in during a freeze are poured early in the day, covered at once and checked again at dusk, when the temperature starts to fall. Where the job calls for hot and windy weather concrete in the same year, we use the same discipline in reverse.

Most specifications set a minimum temperature for placed concrete, a minimum temperature for the subgrade and forms and a protection period. They commonly require that no concrete be placed on frozen ground and that fresh concrete not be exposed to freezing before it reaches a stated strength. Accelerating admixtures, hot water and higher cement content are tools the engineer may allow, and calcium chloride is often restricted where steel is present.

We include a cold weather concreting plan with the submittals. It states temperature triggers, protection methods, curing and the records we will keep, such as daily minimum and maximum readings. The special inspector reviews the plan, and cylinders are cured under the same conditions as the slab so the break results mean something. Test cylinders left in a warm truck cab would report strengths the slab never reached, which is why field curing boxes and temperature records matter. We also ask the local permit office whether additional inspections apply to winter pours.

Warehouses, distribution centers and office buildings often have lease dates that push foundations and slabs into the cold months. Schools and campus buildings hold calendars set by the academic year. Sul Ross State University in Alpine sits on a 647 acre rural campus, and campuses like it often need projects finished before fall classes whatever the winter throws at the crew.

Alpine's elevation brings colder nights than the lower plains, and the Trans-Pecos can freeze hard in a clear stretch. For buildings under cover quickly, we plan temporary heated enclosures, pour inside after the roof deck is up and sequence interior slabs so they cure under warmer conditions. Heaters burning fuel inside a closed space must be vented, because exhaust gases can damage fresh concrete surfaces and endanger workers, so we use indirect-fired units where the enclosure is tight.

Our cold weather scope starts before the pour: removing frost and snow from forms and subgrade, thawing frozen ground with blankets or heaters and checking the temperature of steel and forms. The mix is ordered with heated water or aggregates as needed, and we confirm the delivered temperature on the ticket and with a thermometer.

After placement, we cover the concrete with insulated blankets or enclosures, keep surface moisture from evaporating and monitor temperature at the slab edge, which cools first. We hold protection through the period the engineer specifies, then remove it gradually so the surface does not shock. Muleshoe, where U.S. Highway 84/70 runs through town as American Boulevard, is the kind of place where a winter pour might mean driving blankets, heaters and a generator from a distance, and we price that travel into the plan. A generator that fails at two in the morning with blankets already down is the scenario we plan against, so we bring a spare and assign someone to check it through the night.

Kermit, near 2,860 feet, has a hot arid climate and receives only about 12 inches of precipitation in a year. Even in a climate that reads as hot, cold fronts arrive fast, and a single night can drop temperatures below freezing on a site that was hot at noon.

Oil was discovered near Plains in 1936, and agriculture and oil provide most of the town's taxable revenue, a mix that shapes West Texas building seasons. Oilfield work picks up and slows with prices, and farm buildings are built between harvest and planting. McCamey carries a legislative title as the state's wind energy capital because of the wind farms around it, and wind work happens year-round, so crews often pour foundations in the coldest weeks, with blankets and heaters mobilized alongside the pump. Utilities and energy companies plan for that, and so do we.

Give us the date, the member type and the town. We will review the forecast with the superintendent, set a go or no-go point and price the protection needed so the decision is made before the trucks are ordered.

What air temperature makes you call off a pour?

No single reading decides it. We look at the air temperature, the forecast for the next three days, the member thickness and the protection available. Below roughly 40 degrees F we plan protection, and we call the pour off when we cannot keep the concrete warm through the early cure.

Does cold weather concrete cost more?

Yes. Protection, heat, hot-water mixes and monitoring add cost, and the extra supervision matters too. We list these items so you can compare them with the cost of waiting.

Can you pour on frozen ground?

Not directly. Frozen subgrade must be thawed and the concrete placed on ground that will not freeze again during the early cure. If the ground cannot be protected, the pour waits.

How do you know the slab did not freeze?

We watch temperature at the slab edge, keep protection in place for the required period and break test cylinders kept under the same conditions as the slab. Poor results trigger investigation before the floor is used.