As published at REJournals.com, April 17, 2014:
By Michael Behm, AIA, Senior Vice President, Leopardo Construction, and Mike Machalinksi, Senior Soils Engineer, Testing Service Corporation
One of the most brutal winters in recent memory is now officially behind us, but the headaches from property damage caused by the extreme weather conditions are far from over. Many issues often are not apparent until the weather warms and the freeze-thaw cycle is complete. Although the problems caused by the changing weather are not necessarily a reflection on the quality of design or construction, there are some things that owners and property managers can do to minimize the effects of extreme winter conditions on properties in the future.
The U.S. Weather Service’s Winter Severity Index, which considers snowfall, temperatures and other factors, ranks 2014 among the five worst Chicago winters in recorded history. The damage to property could have been worse—there have been years, such as the winter of 1978-79, when excessive snow damaged or collapsed many roofs, but this year’s heavy snowfall was spread throughout the season rather than concentrated over short periods. The problem in 2014 has been the cycle of extreme, extended cold spells worsened by occasional above-freezing temperatures and rain.
When it comes to how weather impacts site conditions, the concepts are usually rather simple. The cold causes the ground to freeze. The lower the temperatures and the longer the duration, the deeper the frost penetrates. All soils contain a percentage of moisture, and when they freeze the water fraction expands in volume and can cause related heaving, or upward swelling of soils. Additional and potentially worse heaving may also occur due to the formation of ice levels in the frozen soils with associated water pulled up by capillary action or fed from the surface.
Expanding soils and ice can exert extreme pressures on adjacent and buried structures, and such expansion causes movement and damage. Below the surface, these extreme pressures can rupture sewers and water mains, causing all kinds of problems, especially during very cold winters when soils freeze deeper. On the surface, frost heaving can cause significant displacement to asphalt pavements and concrete sidewalks. Normal and expected “heaving” usually is not problematic, but multiple and extreme freeze-thaw cycles can cause severe damage. Chicagoans are very familiar with this phenomenon with potholes in streets throughout the city and suburbs every spring. But the winter of 2014 has been worse than most, and the fallout may be more costly.
Snow tends to be an insulator, reflecting sunlight and acting like a blanket as it protects the ground from the cold and deep frost penetration. In snow covered areas, frost depths may have reached two feet or less, even with the extreme cold. However, the insulating effect of snow cover is lost on sidewalks, parking lots or other areas where it is removed for traffic, parking and pedestrians. Also, a quick thaw and snow reduction followed by another quick deep freeze renders the once insulated ground susceptible to deeper frost penetration.
In the Chicago area, architects, engineers, and contractors plan building foundations for a maximum “frost” depth of 42 inches. New water mains are typically installed with a minimum cover of 66 inches. However, existing and aging utilities in Chicago and surrounding suburbs (some of these structures being 100 years old) may not benefit from adequate soil cover. This year, temperatures remained below freezing for a majority of the winter, and plummeted and stayed well below zero for extended times. The frost depth pushed well past the 42-inch code requirement, and even reached 60 inches or more below pavements throughout the area.
From November through March, major cities like Chicago witnessed the effects of the freeze-thaw cycles with broken water mains and local flooding. Many businesses experienced concrete slabs heaving, cracking and spalling, or flaking around their entrances, which required walks and entries to be ground down in order to open doors. Others observed parking lots, pavers and concrete aprons heaving several inches above surrounding curbs and walks, showing cracking and distress even in new pavement and concrete.
And the arrival of warmer weather does not mean the end of property woes. A great deal of pavement damage may occur once the season changes. Concrete walks and asphalt pavement will settle once the frozen soils thaw and move back towards their original elevations, but cracked concrete walks may create tripping hazards and present problems next winter when the freeze-thaw cycle occurs again. The deterioration of pavements and sidewalks that have heaved and cracked will be accelerated if it is not repaired. Making this worse are the new cracks that increase the amount of water that will penetrate into the underlying soils and freeze the next winter. Parking lots that already needed help before the winter may be in desperate need of repair. Even new asphalt may show distress and require filling and sealing.
Owners also may see more water seepage than usual this year because of the amount of snowmelt and more/new cracks opening up in foundations and masonry systems than usual. After a severe winter “we often see ratcheting, where masonry moves a fraction of an inch in the cold weather, and slides back a different way when it warms up again,” said Ernest Rogalla, Associate Principal of Wiss Janney Elstner. “If an entire structure settles two inches, you may not see damage because it all moves together. But when one corner moves differently than the rest of the building, that’s when there can be problems.” This is also a function of how abrupt the shift is. “A difference of a half-inch of movement over a distance of 30 feet is not as bad as if it occurs over 10 feet,” he said.
The Fixes and Tradeoffs
This resettling is fairly common even in newer buildings, and like other weather related damage to buildings, is not necessarily an indication of poor design or construction. Owners and developers can mitigate risks relating to frost and ice damage, but some measures tend to be viewed as not cost-effective. After a winter like this, it may seem logical to install water mains deeper than 60 inches, but for most owners, the additional protection against frozen utilities is not worth the extra cost of digging the trench a foot or two deeper. It would be much more cost effective to replace old utilities before they break, but many municipalities are budget strapped. Unfortunately, an emergency replacement costs far more than one that is planned.
Sidewalks and pavements are more prone to heaving and deterioration when the underlying soil is not conducive to water drainage, as is the case with northern Illinois’ clay-rich soil. Standard practice is to replace the clay beneath pavements with granular materials that often are structural and not free draining, so they hold moisture in winter that can freeze and promote heaving. There are new base materials on the market that are both structural and enable free draining. While these products tend to cost more, the initial investment may prove to be a cost savings over time as maintenance costs and insurance claims may be tremendously reduced. As a bonus, free-draining base products generally promote environmental sustainability.
Other potential moisture and extreme cold problems can be headed off with relatively simple fixes, and some problems can be mitigated with good property management. Be aware that letting snow pile up next to a building increases the chance that water will seep inside when the snow melts. It also can damage the walls that absorb the moisture and undergo freeze-thaw cycles. Using the wrong products can accelerate the deterioration of concrete surfaces. And salts should never be used on pavements that are less than 12 months old.
When it comes to building structures, owners can prevent water infiltration from ice dams by properly insulating roof lines and removing potential dams before they occur. Owners and property managers should make sure that brick buildings are inspected in the spring to repair cracks in the mortar, a process known as tuckpointing or repointing. “It’s good to do tuckpointing well in advance of the next winter to give the mortar plenty of time to cure before freezing,” Rogalla said. “But doing it too soon after the thaw can be a problem if the building has not finished resettling. Using the proper pointing mortars and techniques are also important. Parapets should get special attention, because they can deteriorate easily and pieces can fall and potentially injure people.”
If you are building a new facility, be aware that some types of brick are more absorptive than others, and when water gets into the pores and freezes, the result is spalling where pieces of the brick flake off. It is difficult to address spalling effectively once it starts. Also, the type of mortar used on new brick veneer buildings is important. Type “S” mortars are used for structural masonry and provide additional strength to a structural wall, but type “S” mortars are not necessarily good for brick veneer applications. Type “N” or normal mortar tends to be more flexible and forgiving in hostile environments and is more appropriate for brick veneer. In this case, stronger doesn’t necessarily mean better.
Although it’s too late to do anything for the winter of 2014, it’s not too late to think about how to mitigate future problems before they occur. Climate experts suggest that the next two or three Chicago winters could be just as brutal as 2014.
Michael Behm, AIA, serves as Senior Vice President at Leopardo Construction in Hoffman Estates. He can be reached at 847.783.3212.
Mike Machalinski, serves as Senior Soils Engineer at Testing Service Corporation. He can be reached at 630-784-4086.
Leopardo earned a double feature in the February 2014 issue of Illinois Real Estate Journal with Big Ten and Universal Technical Institute articles on a two-page spread (pgs 10 and 11). Click here to read the digital issue.
HOFFMAN ESTATES, Illinois (February 12, 2014) — Leopardo recently earned three awards for excellence:
Project of the Year (Fox Valley Associated General Contractors): The FVAGC named the DuPage Medical Group’s new medical office building in Lisle (pictured) as its 2013 project of the year. Leopardo built this $28 million, three-story, 100,000-square-foot medical office building at the intersection of I-88 and I-355. The facility houses a state-of-the-art cancer center for DuPage Medical Group with services such as radiation oncology, infusion and medical oncology.
Safety Excellence Award (Fox Valley Associated General Contractors): The FVAGC recognized Leopardo’s outstanding safety record with its annual Safety Excellence Award in the 250,000+ man-hour category.
Award for Business Excellence (Daily Herald Business Ledger): Leopardo is one of 22 suburban Chicago-based companies honored by the Daily Herald Business Ledger newspaper for business excellence. The Annual Awards for Business Excellence are presented in recognition of business achievement, growth and community involvement.
Since its founding in 1979, Leopardo has thrived on a culture of continuous improvement and has won more than 500 industry awards, including 10 project of the year honors in the last five years alone.
Some of Leopardo’s other awards and honors in 2013 included:
NAIOP Chicago Awards for Excellence: Office Development of the Year for Big Ten Conference Headquarters
Chicago’s American Institute of Architects Architecture Award: Citation of Merit for Manifest Digital
American Institute of Architects Northeast Illinois Chapter: Award for Excellence in Design for the Hanover Park Police Headquarters
Restoration Project of the Year: Landmark Illinois’ Richard H. Driehaus Foundation Preservation Award for Walgreens Bucktown
LISLE, Illinois (January 29, 2014) — Designed to complement a new curriculum that offers real world experience, Universal Technical Institute’s (UTI) new flagship campus in Lisle, IL, will provide a true living laboratory for tomorrow’s automotive engineers.
“They let the curriculum drive the building, not the building drive their curriculum,” said architect Erika Carey, partner, Partners by Design, Inc., Chicago. “We designed this building from the inside out. A lot of discussion early on helped shape the building while giving UTI the most efficient and flexible space to shape their facility.”
Opening in November 2013, the $25 million state-of-the-art Midwest regional campus redeveloped an existing 20-acre site into three interconnected buildings to serve 1,500 students and 200 staff members. Leopardo Companies built the new 180,000-sq.-ft. facility for UTI to feature 22 separate laboratories, including a number of manufacturer and part-specific training areas, and most notably, a cornerstone high bay lab that anchors the three buildings and serves as a focal point for the campus, both internally and externally.
From Building Design+Construction magazine:
The new mixed-use headquarters includes a museum, broadcast studios, conference facilities, office spaces, and, oh yeah, a Brazilian steakhouse.
ROSEMONT, Illinois (January 29, 2014) — With 12 institutions, 280 national championships and 120 years of historic intercollegiate sports, the Big Ten Conference will continue its mission of “honoring legends and building leaders” in a new $20 million, 50,000-sq.-ft. headquarters located in Rosemont, IL.
The new mixed-use HQ will feature a 3,500-sq.-ft. interactive museum on the first floor entitled “Big Ten Experience,” showcasing past and present legends, and is scheduled to open in early 2014. The building also includes a conference center on the second floor for more than 130 annual Big Ten academic and athletic meetings that educate tomorrow’s Conference leaders. Oh, and don’t forget the 10,000-sq.-ft. Brazilian steakhouse, Fogo de Chao, on the first floor. Athletes need to eat, too.
Spring Valley, Illinois (November 4, 2013) – Last Wednesday, construction manager Leopardo, architect Healy Bender and the Hall Township High School Board of Education were joined by local dignitaries to break ground on the new Hall Township High School.
The new $28-million, 133,000-square-foot, three-story high school will consist of an academic building, athletic complex and performing arts center. The academic building will house science, technology, engineering and math classrooms along with a learning resource center and administrative offices. The athletic complex will comprise two gymnasiums, weight training and fitness room, locker rooms and a concession area. The performing arts center will feature a theatre and stage with a high-end sound and recording system. An art lab, kiln room, dark room, set design area, and cafeteria with kitchen area also part of the plans.
The new high school, expected to be completed in early fall 2015, will be built with several sustainable energy features such as permeable pavers, bioswales for storm water management, daylight harvesting and occupancy sensors.
HOFFMAN ESTATES, Illinois (October 29, 2013) – Leopardo recently completed the new, 50,000-square-foot Audi Hoffman Estates dealership, featuring a 12-car showroom, service workshop and customer service center.
Located at 1200 Golf Road, near the intersection of Golf and Higgins Road, the dealership is the first new construction in Chicagoland to use the “terminal” prototype design by renowned Munich-based architecture firm Allmann Sattler Wappner. The design combines the efficiency, performance, luxury and environmental themes that the Audi brand is known for in its vehicles. Chicago-based Dobbins Group was architect of record. Hoffman Estates-based Leopardo served as the construction manager and Colliers International represented the owner.
Watch the video below for a tour of the new Audi dealership while General Manager Brian Hall discusses his experience working with Leopardo.
CHICAGO, Illinois (October 21, 2013) — For the third time since 2007, a Leopardo project was named one of Chicago’s coolest offices by Crain’s Chicago Business. This year, Mintel made the short list of the five coolest offices. Watch Crain’s video tour and read its feature story on the Mintel office space. In 2007, Radio Flyer made the cut, and AbelsonTaylor was featured in 2008.
Rosemont, Illinois (September 26, 2013) — Big Ten Commissioner Jim Delany recently gave Crain’s Chicago Business a tour of the conference’s new Rosemont headquarters, which Leopardo successfully completed on a very aggressive schedule. Today, Crain’s published a video of the tour, which is also embedded below.
“Commissioner Jim Delany hopes what’s inside the building will transform the way the Big Ten does business and interacts with everyone it serves from coaches to university presidents and refs to fans. The new headquarters will include meeting space equipped with the newest technology and a museum called the Big Ten Experience that will be free to public,” said Crain’s reporter Alby Gallun on the video. “The 50,000-square-foot building sits in MB Financial Park, an entertainment district in Rosemont… The new headquarters will include offices for the Big Ten’s 40-or-so employees as well as a command center where conference officials will monitor multiple games in real-time and break down film… The museum, which will open on the building’s first floor later this year, will include video displays and games. One exhibit will allow visitors to photograph themselves in the Heisman pose.”
HOFFMAN ESTATES, Illinois (August 26, 2013) – Hoffman Estates, IL-based Leopardo, one of the nation’s largest contractors, recently started work on four suburban Chicago municipal construction projects. The projects are as follows:
West Chicago Community Recreation Center: Ground was recently broken on a new $15.5 million, 70,000-square-foot recreation center at Reed-Keppler Park. The facility (pictured), which will be the only large one-story recreation center in the Chicago area, will feature a three-court gymnasium, three-lane elevated jogging track, large fitness equipment area, dance/aerobic studio and group fitness room and indoor playground.
New Lenox Police Department: Work started on a new $11.2 million, 31,000-square-foot police station. When complete, the public safety facility will feature a state-of-the-art multi-purpose/training room, and staff areas for code enforcement, investigations and command staff. New detention facilities include an enclosed, secure sally port, detention block, DUI processing area, interview rooms and juvenile detention area.
Bartlett Fire Station: Renovation and expansion work started on the fire protection district’s existing station No. 2. The $2.2 million, 10,000-square-foot project includes demolition of the existing building save for the apparatus bay, which will be renovated. The new addition will feature a kitchen/dining room, dayroom, exercise room, work room, office, meeting room, alarm room, laundry room, living quarters, showers and restrooms.
South Barrington Village Hall: Leopardo began work in August on a two-story, $2.1 million, 10,000-square-foot expansion of the existing 7,000-square-foot South Barrington Village Hall. The project will shift the police department completely to the lower level, allowing the village administration, including council chambers and village offices, to be relocated to the entire upstairs. The lower-level addition also includes a training facility/emergency command center.
Leopardo is widely recognized as a leader in civic and community construction projects. Other recent Leopardo civic projects include a 14,000-square-foot fire station in Romeoville, 200,000-square-foot police headquarters in Aurora, 63,000-square-foot police station in Hanover Park, and a 24,000-square-foot fire station in Mount Prospect.