Question: When is the Best Time of Year to Pour a Concrete Patio?
A Pool and Patio Forum visitor asks: "We live in Michigan, and were wondering if the end of September or early October is recommended to build a new concerete patio? Or should we wait until next spring?"
Answer: If the region in which you live is not experiencing extremes in temperature -- one way or the other -- than either spring or fall are both good times of the year. You know where you live and the variables that can occur during these months. Has it been known to dip below 50 degrees in April or May? Likewise, in October or November?
However, if you can't recall just how unpredictable the weather can be or are new to a region, check the Farmer's Almanac, or a local newspaper or community website. For Michigan, it would probably be safe to pour your concrete patio in September or maybe early October. Also, you might want to check with the contractor's license board website for your state.
According to the Portland Cement Association:
Temperature extremes make it difficult to properly cure concrete. On hot days, too much water is lost by evaporation from newly placed concrete. If the temperature drops too close to freezing, hydration slows to nearly a standstill. Under these conditions, concrete ceases to gain strength and other desirable properties. In general, the temperature of new concrete should not be allowed to fall below 50 Fahrenheit (10 Celsius) during the curing period.
This information holds true for do-it-yourself projects and for those built by professional contractors and construction crews.