Working in a Winter Wonderland.
The beginning of winter conjures mixed emotions: holidays (good), travel delays (not so good), the hygge lifestyle (very good), darkness at 5:30 p.m. (very ungood), snow days (outlook age-determinant).
For workers in the construction industry, winter is no fireside snooze; it’s a season beset with unique challenges yet beholden to the same schedule and cost pressures that drive projects year-round.
In our final issue of Bytes & Insights for 2023, we’ll share how experienced contractors leverage the power of good planning to sequence critical scopes, minimize rework, keep their people safe, and deliver quality projects on time.
How to Safely Work in Cold Weather
Ask anyone in the construction industry who has been through a few cold winters, and they’ll tell you that staying safe on site is a different animal in winter than at the height of summer. Read below for four easy tips on working safely when your winter wonderland gets a little too frosty.
Stay Warm
Let’s start with the obvious: winter is cold, and humans don’t do well in cold. Safely completing work in winter is predicated upon a labor force that has the proper clothing and equipment to stay warm. Dress in layers that can be easily added or removed as conditions change throughout the day. Don’t forget insulated headwear; a hardhat alone is little protection against heat loss.
Once you’ve gotten your own gear squared, be on guard for any team members exhibiting the symptoms of hypothermia below, and personally follow up that they receive appropriate care.
Shivering or chattering teeth
Pale or discolored skin
Exhaustion or drowsiness
Confusion or memory loss
Lack of physical coordination or speech control
Shallow breathing
Inability to perform routine tasks
This advice isn’t just for crews in digging out from a foot of snow in Buffalo or facing sub-zero temperatures in Duluth: even temperatures above 50 °F can result in hypothermia, particularly if the person exposed is wet or exposed to direct winds. Check the weather forecast regularly and allow for a margin of error by preparing for conditions that are 10–15 °F colder than anticipated. You can always shed those extra layers as necessary.
Stay Dry
As alluded to in the previous section, Item 1a in the battle against winter is staying dry. Cold air can’t hold nearly as much water vapor as warm air (more on that later), so it takes much longer to evaporate it. Translation: when you get wet in winter, you stay wet.
Avoid exposure to melting snow, rain, and muddy ground, and bring a change of clothes for activities that may cause you to sweat excessively—once you stop exerting yourself, it won’t take long for that sweat to turn into a damp chill.
Stay Focused
When physical conditions are less than ideal, it’s easy to become distracted. Snow, wind, or even extra layers of clothing may not feel pleasant, but you can’t afford to let them steal your focus away from the task at hand. Construction work carries inherent risks that demand your full attention. If you see a coworker distracted or struggling with weather-related issues, ask how you can help and let your supervisor know of the problem.
Stay Vigilant
Nobody plans to suffer from the cold, so it’s fair to say that anybody shivering on site has been caught off guard to some degree. Once colder weather begins to set in, keep a coat and gloves in a car or locker, as well as an extra change of clothes and pair of boots.
Perhaps most importantly, make sure that all personnel on site from junior laborers to senior supervisors to corporate managers are trained to recognize the signs of hypothermia/frostbite and provide the proper interventions to those in need.
Site personnel should be well-versed in identifying active hazards and be ready to stop work when tasks are being performed without the proper cold weather safeguards, then communicate and follow-up that corrective actions have been taken.
For more insights on working safely in cold weather, check out our article on gray.com.
The Snow Must Go On
Contrary to a common notion, construction does not grind to a halt in cold weather. Even in more northerly regions, crews forge ahead with putting work in place. Challenging under the best conditions, this becomes even more difficult when confronted with frigid weather.
In such conditions, experienced project managers, designers, and site leadership know that an ounce of prevention is worth a pound of cure. Prioritizing critical scopes, developing flexible schedules, and procuring and protecting essential materials can put teams in position to succeed even when adverse weather threatens to upend the daily routine. Ensuring that the proper personnel are on site with the clothing, tools, and materials they need to effectively complete their tasks in winter weather requires close collaboration and extensive planning among these stakeholders.
Design-build project delivery facilitates such planning, uniting the design and construction phases and enabling more inclusive planning, faster decision-making, and shorter project timelines.
So which scopes aren’t suited for winter weather?
For starters, anything that relies on higher absolute humidity to assist processes. Warmer air can absorb and hold more water vapor than colder air because its molecules are less dense. For example, air molecules at 40 °F can hold more than double the volume of water than air molecules at 20 °F.
Sure, science rules, but how does this matter for a construction workforce?
In more ways than you’d care to count. Any work processes that involve the evaporation or absorption of moisture to dry or cure will take longer in cold weather and elongate your schedule. These include working with concrete, mortar, grout, drywall mud, adhesives, paint, and more.
Walkways or equipment wet from rain, snow, or mud will fail to dry quickly and risk turning icy or locking up. Any worker whose clothes become saturated in freezing weather will face the same predicament and be at greater risk of hypothermia and frostbite.
Conventional wisdom dictates that you complete site grading, foundations, and concrete work before the onset of the cold season. Winter’s freezing temperatures can cause subgrade ice to form, which then thaws in the spring and can leave cavities that undermine the strength of your foundation. Without extensive measures to heat and insulate materials, concrete poured in cold weather may take too long to dry or fail to cure.
If possible, get your building shell dried-in before the start of winter so that your people can focus on interior work and be less at risk of exposure to freezing temperatures, winds, and precipitation.
Learn More: How Maintenance Teams Can Evaluate Roof Snow Loading Issues After Excessive Snowfall.
At the end of each day, take time to prepare your site for the next day’s work:
Put all tools away
Clear walkways of mud and snow
Cover openings in the building envelope when possible
Use blankets and tarps to protect materials from cold and moisture
Use temporary heaters to maintain sufficient temperatures for people and property. Keep equipment such as gas generators and extra fuel on hand in case of a power outage, and make sure you have plenty of ice melt to keep walkways and stairs clear.
Making Pour Decisions
Generally, construction managers do their best to sequence project scopes so that pouring concrete foundations and slabs occurs in warmer months, since cold air prolongs the drying process and freezing temperatures can compromise the concrete’s strength and durability. However, circumstances sometimes dictate that concrete work be put in place during the winter. This can be done successfully, but it does demand that supervisors take time to ensure that a wider array of considerations and conditions are met.
Foremost among these is the necessity to avoid exposing critical materials to freezing temperatures. Concrete’s strength and structure derive from the crystallization of water as it bonds with cement. When conditions become too cold, it interferes with the curing process and can cause water molecules to freeze before they bond with the mixture. If not properly prepared and maintained throughout the drying process, concrete poured in cold weather may need to be torn up and completely redone—dealing a major blow to your project’s schedule and budget.
Pouring concrete is as much a science as it is a trade, and professionals must understand how to work within the physical laws that govern its chemistry and mechanics. The American Concrete Institute (ACI) has developed detailed guidelines that specify best practices for mixing, placing, and maintaining concrete in cold conditions, including tables for minimum temperatures, required protection periods, and maximum allowable temperature drops after protection.
But it’s not only concrete work that requires special treatment in winter weather. Metal work such as steel erection and welding can also be negatively impacted by cold temperatures and require processes such as pre-heating and post-heating to avoid problems such as weakened steel, cracked welds, and inadequate weld penetration depth.
Byte: Be sure to consult with subject-matter experts when executing outdoor scopes in winter. A quick training session may wind up saving you from major weather-related losses.
However you’ll be spending the holidays, keep safety top of mind for yourself and those around you. And while there’s still time, consider that some nice wool socks are a low-key great gift idea…
