Our communications team interviewed David Niswonger, A.R. Brouwer’s Vice President of Operations, to learn more about winterizing the construction site.

How does A.R. Brouwer Company prepare a construction site to continue working during winter? At A.R. Brouwer, we take the health and safety of our construction crew very seriously. Therefore, we implement work plans to identify and eliminate cold weather safety hazards. We also protect our client’s existing property and work with our subcontractors to avoid costly repairs and downtime by remaining diligent with preventive maintenance. Furthermore, our team will prepare and work to have all the site curbing and the base course of asphalt in place so we can plow the site. We also enclose the building to heat the interior to keep construction moving throughout the winter months.

Is there special equipment that A.R. Brouwer uses to keep the crew and construction safe and warm? We use temporary heaters or furnaces to keep the building tempered to 50-60 degrees so work can be performed. It is essential to use indirect heat so carbon dioxide doesn’t enter the work area. It can injure or kill workers and carbonize the concrete. We also pay close attention to exterior temperature and limit time spent outdoors on cold days. We also monitor workers for cold stress. We will send our exterior crew home if it gets too cold to work on the exterior of the construction site.

Is there special training and education the construction crew needs to take to work during the winter months? The A.R. Brouwer Company follows the guidelines for cold-weather construction developed by the Masonry Industrial Council. They provide education and created mandatory cold weather construction practices required by the International Building Code and Building Code Requirements for Masonry Structures. Our team also follows standards developed by the American Concrete Institute (ACI) for concrete. The ACI Standard establishes methods for cold-weather concreting for thin sections and mass concrete. They also provide resources for heating materials, accelerators, and anti-freezes, curing and temperature records during curing, subgrade (or base) preparation, protective coverings during curing, and form removal are discussed for both types of jobs, and preferred methods are indicated.

If your project schedule requires concrete to be poured in cold weather, what are critical factors to know? The first critical item is the ground we pour on. The ground cannot be frozen or have frost in it. Frozen ground will slow the curing process and potentially settle under the concrete. Because concrete has a large percentage of water, it can freeze. If concrete freezes, it will lose its strength. ACI recommends that the maximum temperature difference between the ground and the poured concrete should not exceed 30 degrees. When the temperature drops below freezing, concrete should be covered and heated to maintain temperatures between 55 to 60 degrees.

What can go wrong while pouring concrete in cold weather conditions? The concrete can freeze. Our crew will have to tear it out and replace it when this happens. When we pour concrete, we pull test cylinders to make sure that the concrete reaches its designed strength. We also perform break tests at 7 days and 28 days.

How can a ready-mix subcontractor help overcome the problems associated with cold weather concreting? The concrete suppliers heat the water and sand to increase the concrete’s temperature so that it is ready to pour when it arrives at the site.

What changes can a supplier make to help the concrete withstand cold temperatures? Heating the sand and water is the first step. They can also add special non-chloride water reducers and accelerants to the concrete mixture to help reduce the amount of water in the concrete and speed up the curing process.

What are some mistakes frequently made when cold weather concrete is scheduled for pouring? Pouring on frozen ground, unfortunately, happens and is avoidable. To prevent this, our crew covers the ground with frost blankets to keep the frost out. If the ground is frozen, we cut out the frost and bring in non-frozen sand or stone to return the grade to its original state. Another option to prevent the ground from freezing is to use hydronic heat to heat or thaw the ground. The hydronic heat systems transfer heat by circulating glycol/water solution in a closed system of pipes or hoses. The pipes or hoses are then covered with frost blankets to keep the heat in and thaw the ground. We also work to prevent the concrete from freezing, and our crew won’t pour concrete when temperatures are below 30 degrees without covering and heating the concrete for a minimum of 24 hours. When temperatures are between 32 – 40 degrees, we cover the concrete with frost blankets to avoid wind burn and to maintain the heat generated by hydration on the concrete.

A.R. Brouwer has more than 25 years of experience constructing buildings that last. Our team works efficiently and safely every season of the year throughout Southeast Michigan. We have hands-on expertise winterizing the project site and preparing our construction team to meet our client’s project expectations and schedule . . . safely. Contact us and find out more about how we can build your vision.