Hot Weather Concrete: How to Pour Above 90°F
Chilled water, retarders, evaporation reducers — exactly how to keep summer pours from cracking.
Hot, dry, windy weather is concrete's worst enemy. Water evaporates faster than the slab can use it, causing plastic-shrinkage cracks within hours.
Pour early
Start at sunrise. Wet concrete should never see direct mid-day sun above 90°F.
Cool the mix
Ask the supplier for chilled water or ice in the mix. Every 10°F drop buys 5–10 minutes of working time.
Use a retarder
Set-retarding admixtures extend working time by 30–60 minutes — critical when finishing in heat.
Spray evaporation reducer
An aliphatic alcohol mist between screeding and floating prevents the surface from drying before the slab is ready.
Cure aggressively
Start curing within an hour of finishing. Soak burlap or use curing compound — do not let the surface dry.
Use the calculator to lock in your yardage before you commit to the supplier.
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