Hot weather brings added considerations for contractors placing or repairing concrete, should be aware of for placing concrete or performing concrete repair in hot weather, writes Dick Tharpe from Sakrete. Tharpe offers tips on combatting reduced setting times, higher water demand, increased risk of cold joints and other conditions that arise in hot weather.



There have been scores of articles written about the challenges involving ready-mixed concrete placement when faced with hot weather. This article will focus on hot weather concreting tips and best practices for those smaller projects utilizing bagged concrete or concrete repair materials. Our focus is to help concrete contractors and do-it-yourselfers alike to employ the right hot-weather concreting precautions and practices for any given year.

According to the American Concrete Institute (ACI), any time the ambient temperature exceeds 77º F (25º Celsius), a hot weather plan for concreting should be in place. The ACI also sets the maximum temperature for plastic concrete as 95º F (35º Celsius).

Let us review some of the adverse conditions present in hot weather concreting on smaller projects:

  1. Reduced setting times which include pot life, placement, and finishing times
  2. Greater risk of cold joints
  3. Higher water demand
  4. Detrimental effects resulting from re-tempering with water
  5. Increased urgency for applying a curing method to the freshly placed materials
  6. Increased potential for plastic shrinkage cracking and crazing
  7. A faster set can lead to poor consolidation of the materials, bugholes, and voids
  8. Risk of lower ultimate strength due to higher water content and high curing temperatures


More On Hot Weather Safety

Safety Expert John Meola Shares Heat Stress Management Tips: When summer temperatures rise, many construction workers are at risk of heat stress.