Concrete Information and Tips
Even though concrete is a versatile substance it does have its limitations that you should consider. Concrete is affected by temperature, too hot and it dries with cracks, too cold and it takes forever to set-up. There are chemicals available that will allow experts to pour concrete in even the worst conditions, but trailered ready mix is not intended for these specialized applications. But if you make proper plans in advance you should be able to pour concrete anytime.
Most small concrete pours should be planned when temperatures are between 60 and 90 degrees Fahrenheit. This means that the concrete will begin to set-up in a reasonable time but won’t set-up before you have a chance to touch it up.
Hot Weather Tips
Plan ahead. If you can make arrangements to pour in the cooler time of the day, this will minimize the effects of trying to finish the concrete in the heat.
Wet down all the forms and ground just before you pour in the concrete. This will reduce the rate of evaporation of the moisture in the concrete mix.
Avoid adding water to the mixture because it will lower the strength, increase cracking and reduce the durability.
Limit the time between placing the concrete and final finishing.
Use a fog type spray nozzle to maintain surface moisture and to prevent evaporating away the “bleed” water out of the concrete mix before it can be troweled smooth.
Provide sunshades to control the surface temperature on the exposed surfaces.
Erect windbreaks to reduce the chances of a dry wind that will cause the surface to cure too fast and crack.
As soon as the concrete is finished, begin a moist cure by keeping the finished surfaces and pour area damp for the next few days. On extremely hot or windy days, it may be best to reschedule the pour for a day with more favorable conditions.
Cold Weather Tips
Do not plan to pour concrete when the temperatures will not get above 60 degrees Fahrenheit.
If you can wait until the sun is shining on the pour site, then wait.
Use a concrete mix with a low water volume so that it will have less moisture to reduce the cure time.
Provide a curing membrane that can be as simple as a plastic tarp or as sophisticated as a concrete curing blanket.
It will take long to cure so you will want to take precautions to keep unwanted travelers from making an impression on your hard work.
Too much water weakens the Concrete causing sandy surfaces, peeling and chipping.
Too little water Causes the Concrete to cure too fast and will result in wind check and cracking.
Concrete will reach half its strength in 10 days and its full strength in 27 days hot days or windy days can affect the finish of your job.