Promotions Committee Corner: Cold Weather Tilt-Up
By: Kim Corwin, A.H. Harris/HarMac Rebar
For years, site-cast Tilt-Up construction has been dominant in warm-weather states like California, Florida and Texas. But in today’s challenging market, innovative contractors are bringing the method to the northern states, proving that Tilt-Up can be a cost-effective construction solution for colder climates, too.
“There is still a great misconception that site cast Tilt-Up construction is only suitable in areas with year-long sunshine,” said Ed Sauter, executive director of the Tilt-Up Concrete Association (TCA). “However, not only are northern contractors proving this to be false, but many are leading the industry innovation and application of the medium to new building types.”
Although Tilt-Up construction has historically experienced the most growth in the sunshine pockets of the United States, there are certain aspects of Tilt-Up that make it more conducive to cold-weather construction. Since floor slabs are cast early in the construction process to facilitate casting of the wall panels, workers benefit from a hard, dry work surface and a quick building envelope. Once the walls are constructed, valuable workdays won’t be lost due to harsh weather, as is commonplace with other building methods. Today’s construction schedules are driven by owner’s program requirements – not weather. New technologies that allow for winter construction are eliminating previous objections to Tilt-Up as a winter-constructed envelope system.
Like any other type of construction performed under wintry conditions, Tilt-Up is not without its challenges. To meet these challenges, many contractors are turning to innovative solutions such as ground heating systems, special mix designs, specialized insulating systems and intensified placement strategies to equalize conditions and facilitate construction in all types of weather.
For instance, to construct a 45,500-square-foot manufacturing facility for aerospace machinist Brinkman Precision in Rochester, N.Y., Tilt-Up contractor, The Nichols Team, integrated a glycol heating system into the pour area to help maintain a consistent 60-degree slab temperature, even as outdoor temperatures hovered around 15-degrees Fahrenheit. To create architectural interest on the panels, The Nichols Team cast-in reveals using plastic extrusions, which stay flexible even in bitterly cold conditions. Although technological innovations like these can add a slight cost to a project’s bottom line (The Nichols Team estimates that the glycol heating system added about $3 to $4 per square-foot of wall panel), the payoff is an efficient construction schedule: the panels for the Brinkman Precision project were formed and poured in just four weeks, and the entire building was completed in under six months.
“The technology is out there to build in any type of weather conditions,” says John Nichols, President of The Nichols Team. “You just have to have an informed customer who is willing to invest a small premium in order to achieve an accelerated schedule.”
Plenty of advance planning — including purchasing five-gallon buckets of water-based bondbreaker to facilitate on-site mixing and reduce the need for outside storage and potential freezing, as well as bumping up the number of crew members from eight to 13 on pour days so work could be completed more quickly — was equally crucial in ensuring The Nichols Team’s success.
“Our membership in the TCA and the CON/STEEL Alliance, as well as our strategic partnership with our supplier A.H. Harris has dramatically accelerated our learning curve and cemented our credibility as experts in Tilt-Up construction,” said Nichols.
In addition to the benefits Tilt-Up concrete provides during construction, buildings constructed via the medium also hold plenty of value for the end-users in cold climates. Concrete naturally retains and stores energy, and the use of insulated panels (such as THERMOMASS Insulated Sandwich Panels used on the Brinkman Precision project) can push this retention even further, meaning users can spend less money on heating during the winter. In some cases, the heating systems used to regulate temperatures for slab pouring can be integrated into the finished building as an energy-efficient in-floor radiant heating system. Tilt-Up concrete walls also provide a reduction in noise from outside traffic and weather, which increases comfort levels. In addition, insulated panels often allow the building owner to reduce the size of the HVAC system and take advantage of the mass effect of concrete that enables concrete to absorb and store energy.
The Brinkman project was the fifth cold-weather Tilt-Up project The Nichols Team has completed in Rochester, and it certainly won’t be the last. “I am extremely confident that Tilt-Up will gain market share in the Rochester area quickly,” said Nichols. “In 2010, we will be constructing a 60,000-square-foot faith center with Tilt-Up panels specified by the project’s Chicago-based architect. This facility will be a showcase for Tilt-Up in the area and will put to rest any reservations about design versatility for the design community in our area.” The Nichols Team has also committed to ensuring that their team is certified through the joint Tilt-Up Concrete (TCA)-American Concrete Institute (ACI) Tilt-Up certification program. Their six-person crew is certified through the program.
The Nichols Team has also created an innovative strategy to get design professionals in the area excited about Tilt-Up. The firm holds Tilt-Up parties during panel erection and invites people in the area to attend. “Our first Tilt-Up party had five attendees and our last had nearly 100,” said Nichols. “Awareness about Tilt-Up is advancing rapidly and we are gaining inroads with architects and engineers who can now see the benefits of Tilt-Up in person.”
Thanks to innovative technology and contractors who are willing to embrace new techniques, Tilt-Up’s reputation as a fair-weather construction method may soon be a thing of the past.
