Cold Weather: A Construction Game Changer
February 12, 2015
For most people, the chill in the air means grabbing a coat, but for those of us in construction, winter shifts our entire game plan. Beyond safety considerations, frigid temperatures affect our means and methods for major construction activities.
To illustrate the impacts of constructing in the cold, take for example our work on the Great Falls Clinic Medical Center in Great Falls, Montana. The project team faced the challenge of completing the structural steel and concrete skeleton of the replacement hospital during the harsh winter months, with severe cold snaps in October and November bringing snow and temperatures as low as 20 below. Knowing it is ill-advised and unsafe to erect structural steel coated with frozen precipitation or to perform welding in temperatures below freezing, the team planned ahead to ensure quality without risking schedule. The team preheated the materials necessary for welding the structural steel and proceeded with erecting the steel and welding once the site was free of snow and ice. Thanks to their planning and extra precautions, the team was able to top out the structure in early February.
Another current project that illustrates these cold-weather precautions is the second phase of our work at The Banks in Cincinnati, Ohio. Due to expanding scope and shifting project start dates, the construction team for the two-tower, city-block-wide mixed-use complex is pouring concrete through the winter months. With Cincinnati’s average winter temperatures in the 20s and wind chills in the single digits, the team is taking extraordinary measures to ensure the concrete sets properly, meets quality standards, and will provide for the facility’s full life-cycle.
While pouring concrete throughout this winter, The Banks construction crew fully encloses the deck below the slab pour with tarps, placing several 650,000 BTU heaters underneath the active deck to elevate the air temperature. To achieve even heat distribution, the team relocates the heaters multiple times each day. This below-slab heating procedure continues for three days after the pour to prevent any portion of the ready mix from freezing. The team takes measures above the deck as well, placing insulating blankets over the newly poured concrete. Increasing the temperature surrounding the concrete allows it to cure and reach its full strength over the next several days. While costlier than traditional concrete work, this process protects the integrity of the concrete during cold weather pours and ensures long-term structural success.
Both the Great Falls and The Banks teams are focused on moving safely and steadily through the remaining winter work on their projects and are hoping General Beauregard Lee (and not Punxsutawney Phil) is right about an early spring!