Keys to Converting Tilt-Up
By: Ed Sauter, Executive Director Tilt-Up Concrete Association
Adaptability is key to success in today’s design and construction industry, where having the wisdom to change direction often makes the difference in bringing a project in on time and under budget. One such change in direction that is becoming increasingly prevalent among new construction projects is the conversion of a project to the Tilt-Up method of construction. In fact, Tilt-Up construction continues to gain favor among designers and owners looking for solid and unique solutions, while contractors deliver what remains one of the fastest- growing industries. However, the key to success is understanding how to recognize if Tilt-Up is a fit and proven estimating techniques. With this basis, the method can be appropriately applied for project success.
“The Tilt-Up construction method continues to gain market share for several reasons: speed of construction, advances in architectural treatments, and adaptability to markets such as schools, retail centers and office buildings,” says Jim Baty, TCA Technical Director.
When these benefits of Tilt-Up are considered, many times converting a project to Tilt-Up is the best solution to a project’s unique challenges. Glenn Doncaster, President of Citadel Contractors, an Apex, N.C.-based firm specializing in Tilt-Up construction and design-build project management, explains there are two common ways a project is converted to Tilt- Up.
“First is redesigning the existing documents,” says Doncaster. “This can be a tough process because
you are really in a value-engineering position. However, we do this successfully all the time. The second method of converting a project to Tilt-Up is when Tilt-Up is considered to be the designer’s preferred method. After working with Tilt-Up, many designers recognize the versatility and durability of the system and make it their construction method of choice.”
REDESIGN TO TILT-UP
Projects often become candidates for redesign to Tilt-Up for several reasons, though the most common reasons are inability to meet the current schedule or budget with the existing construction method. When a project is over budget, the economy of Tilt-Up construction with a proven cost-effectiveness becomes attractive. With regards to meeting tight schedules, the lack of dependency on manufactured parts helps contractors solve time constraints. Further, value engineering (often a dreaded term) becomes a frequent factor in redesigning to Tilt-Up. However, Doncaster cautions members of the industry not to simply choose Tilt-Up as a cheap solution.
“When converting to Tilt-Up, be careful to not just do it on the premise that Tilt-Up is cheaper,” says Doncaster. “Offer value. Show that you improve the schedule. Don’t use the conversion as a means to create the mindset that Tilt-Up is simply cheap unless tied to value.”
A redesign to Tilt-Up offered great value to the construction of the 11,000- square-foot St. Julia’s Catholic Church in Siler City, N.C. Originally designed to be a load-bearing masonry facility, this building has walls with a shape and height that presented budget and constructability issues. But, by switching to load-bearing insulated panels, the designers had the freedom they needed to construct this facility. Because of the project’s many bracing and erection challenges, some panel engineers and product representatives thought the project could not be done. For example, one wall of the bell tower was designed to be sloped, and traditional masonry would not allow this without expensive structural steel back-up. Space was very limited on the site, so all the panels were constructed either on the floor slab or small casting beds. This solution still did not allow for enough space, so panels were both stack-cast and sequenced to match the required erection schedule.
To create visual appeal for the facility, heavy architectural reveals developed shadow lines, while textured paint was used to emulate a plaster finish. Engineered wood beams and a tongue-and-groove wood ceiling in the sanctuary create a striking interior, complementing the strength of the concrete, while stained-glass windows enhance the stark contrast of wood and concrete. The bell tower is composed of panels laid on one another to create the appearance that the tower is leaning. And the use of insulated concrete panels allowed the owner to achieve cost and energy savings without altering the desired appearance. Centurion Construction Co. of Raleigh, N.C. performed the Tilt-Up construction on this project, which received a TCA 2006 Tilt-Up Achievement Award.
A second example of a project where redesign to Tilt-Up provided significant value to the owner is The Harbor Shops, a 135,350-square-foot retail facility in Fort Lauderdale, Fla. Originally designed as a masonry facility, this project underwent a major redesign in its early phases to make it adaptable to Tilt- Up, which required the construction team to work together to value-engineer the project. Composed of five buildings that were erected simultaneously, the construction process was coordinated extensively to ensure that all of the trades were in order and that the project was running smoothly. TILT-CON Corporation of Altamonte Springs, Fla., performed the Tilt-Up construction for the project on a site with poor swampy soil, which necessitated the construction of a special slab. After drilling piles, the contractor placed the building pad sub-base and then installed a geo-grid foundation system support below the bottom depth of the grade beam and foundation elevations. The fiber mesh system used polypropylene fibers rather than a welded wire fabric to provide the additional structural support to the systems.
One of the project’s goals was to achieve a Key West look and feel. The design team responded accordingly, using a variety of building heights, towers and reveals. Bevel reveals, overlapped panels framing blocks of color to offset the panels, sunshades and a second-story balcony all add architectural appeal to the retail center. Designed for flexibility, knock-out panels were used so future building and storefronts could be created. Viewed as a success by the community, this project was part of a redevelopment/revitalization effort for this area of Fort Lauderdale and received a TCA 2006 Tilt-Up Achievement Award.
IS TILT-UP RIGHT FOR THE PROJECT?
Just because a project has schedule and budget concerns doesn’t always mean Tilt-Up is the best solution for the project. “There are, unfortunately, examples of buildings that should not have been Tilt-Up, or where the use of Tilt-Up, with a few dramatically placed panels here and there, was almost incidental to the design,” says Hugh Brooks, author of the first four editions of the Tilt-Up Design and Construction Manual and one of the founding members of the TCA. “These square-peg-in-round-hole cases occur either from not knowing why and when to use Tilt-Up or because the architect tries to design the ultimately disguised Tilt-Up building.”
If you are asking yourself if Tilt-Up is an option, consider the viability of taking the architectural vision and panelizing it. Also, what are the site conditions? How much floor space does the project encompass, and can the panels be cast on other portions of the site if need be?
CONVERTING WITHOUT LOSING THE ARCHITECTURAL VISION
Once you determine Tilt-Up is appropriate for the project, it is important to evaluate the architectural possibilities. Look for ways to execute the architectural motif and concept using Tilt-Up. For example, options for openings include curtain walls, as well as punched or storefront windows. If depth is desired, vary the reveals in width and depth instead of being constrained by standard reveals. Or incorporate architectural relief through projection, panel laps, decorative panels, reveals and/or recesses. Architectural features also can be easily applied to the panels with EIFS and structural foam elements, giving architects yet another option for the execution of their vision. The use of colors is also key and achievable through a variety of coatings. Simply, look for ways to make it happen.
Architectural and aesthetic freedom are displayed in the St. Sarkis Armenian Church, a 2006 TCA Tilt-Up Achievement Award-winning project. A dream come true for this congregation, Tilt-Up was selected for this 15,000-square-foot facility in Charlotte, N.C., because of its ability to provide a faux stone finish, lower the construction cost, and offer thermal efficiency due to the insulated Tilt-Up panels. The congregation wanted to have the exterior of the church match the tuffa stone that is native to Armenia. A true stone building would have doubled the cost of construction, and an EIFS solution would not have been durable. Stephens Architectural Associates of Laurel, Md., designed the concept to fit the congregations’s needs, and Seretta Construction of Apopka, Fla., performed the Tilt-Up work, which included more than 10,000 feet of reveals to create decorative patterns in the concrete that mimic a stone building. Lining up the reveals from panel to panel to give the building the stone look was essential in keeping the symmetrical patterns that give the church its unique stone finish.
In order to minimize drilling and cutting of the concrete, boxes for electrical wiring devices were installed in the panels during the casting process. In addition to the wiring boxes, all electric features, switches, lights, and alarms were placed into the panels to avoid cutting them into the panels, which saved both time and money. Located on a tight site, casting beds took up much of the construction location, so precise coordination of the casting bed placement and the panel erection sequence was necessary. Two inches of insulation placed in the panels give a material R-11 value and a performance of far greater, which will minimize operating costs for the church. Also, the interior surface of the panels was able to be exposed and finished with a durable, flecked hard-trowel finish, avoiding costs associated with interior metal studs, insulation and gypsum board.
The congregation is extremely pleased with the outcome of the project. The church features a sanctuary, family life center, utilities for an upcoming ketches, an office area and a classroom area.
TILT-UP AS THE PREFERRED METHOD
The second method of concerting a project is Tilt-Up as the preferred choice. This method requires a believer – the engineer, architect, owner, developer, or contractor. When a project’s time and budget become significant issues, Tilt-Up can often provide the solution. In these cases, however, estimating is key. According to Baty, one of the most common questions received at TCA headquarters is how to best estimate the cost of a Tilt-Up project. From an engineering perspective, it is very important to begin the estimating process by gathering site-specific information.
“I believe in developing a cost estimate based on local codes and conditions – not merely previous cost histories,” explains Philip Kopf, President of The Kopf Consulting Group, an Atlanta- based engineering firm. “You have to be careful if you just use historical data to put together your estimate, as it doesn’t account for the changes in the codes.”
For example, though a project may be very similar in size and scope to a past project, pricing from the past project would not account for recent changes in the code regarding seismic issues. From snow and roof design loads to bay spacing and how the roof will be drained, site-specific information is key for successful estimating.
“In my opinion, if you are an engineer, you are doing your clients a disservice if you simply estimate based on past experience and adjust for today’s cost of materials,” says Kopf.
Being aware of current codes and material costs is especially important when Tilt-Up contractors are estimating with incomplete information at hand. Many times in today’s design-build environment, Tilt-Up contractors are given limited information from which to put together an estimate.
“If we get a schematic, we can make an educated guess as long as we are estimating the foundation, slab and walls as one package,” says John Neyer, President of Neyer Construction, Inc., a Cincinnati, Ohio-based general contractor. “The biggest question I have is how many pounds of reinforcing will be in the wall, since this price changes so drastically. Also, my biggest threat and competition is precast, so many times my estimates are more about speed of delivery than about dollars.”
Clay Fischer of Woodland Construction Co., a Tilt-Up subcontractor located in Jupiter, Fla., knows first-hand about making estimates based on incomplete information. “As a Tilt-Up subcontractor, we often get a lot of jobs that are somewhat designed with regards to the roof, but not the panels,” says Fischer. “Therefore, one of the first things we do to make sure we assemble a realistic cost estimate is to get an experienced structural engineer involved. I should note that we are careful to match the right engineer with the right project.”
For example, on complex projects, Woodland Construction consults with an engineer who specializes in that type of construction. That same engineer may be too specialized for a project such as a box warehouse. When it comes to conceptual projects, though, such as a multi-building school campus, estimates can be a challenge. In such cases, by partnering with the engineering consultant, Woodland Construction can assemble its best estimate based on historical data coupled with today’s prices.
“On simpler buildings, if we get involved early enough — which is easier with private developers – we can pull the engineer in right away,” explains Fischer. “If we have the opportunity to use one of our engineers, we’ll commit to his or her budget because we trust that engineer’s experience. This is a win/win situation for us, as well as the owner/developer, since we are willing to stand behind our number, and the numbers are pretty firm.”
Engineers such as Kopf understand the importance of this type of coordination between engineers and Tilt-Up contractors when putting together an accurate estimate. In fact, Kopf says it takes a team approach to put together a good estimate.
“Although I don’t get paid to do pricing work, I have a vested interest in putting a lot of time and effort into assembling a meaningful estimate so we all get the work from the owner,” says Kopf. “That is why one of the first phone calls I make in my preparations is to the contractor so I can get the prices for the concrete and steel, as all of this costing information is utilized in the analysis and worked into the estimate. It also is important that an engineer includes as much detail as possible and explains how the numbers were derived so the contractor understands the pricing.”
Laurence Smith, a partner and director at J.W. Lindsay Enterprises, explains how his firm, a Dartmouth, Nova Scotia-based design-build contractor, achieves accurate estimates of Tilt-Up projects. Smith says J.W. Lindsay Enterprises takes a three-step approach when estimating. The first step is reviewing the take-off – all factors that cannot be controlled, such as height of building, usage, etc.
“Although we have to make some guesses, they are educated, as we go through every panel and review dimensions, quantities, thickness, how much rebar, rigging considerations, etc.,” says Smith. “In the second step, we move to pricing, which is job-specific since the price of concrete and rebar differs from city to city. We also take into consideration the time of year construction will occur, whether or not bay spacing has been determined or if we can impact that decision, and more.”
J.W. Lindsay Enterprises’ third step involves analyzing the estimate to determine if it seems reasonable. For example, if the price is drastically different compared to other jobs of similar size, the firm finds out why.
“If the last four jobs we did averaged $10 per square foot, and this one comes out to $18 per square foot, we must be able to answer why,” Smith says. “What is different?”
Another key to estimating accurately is understanding the project’s architectural elements. That is why it is key to ask questions upfront, but if you don’t get face time with the owner, this can be a real challenge.
“An owner or architect new to Tilt-Up may not have the experience to accurately estimate architectural features, and this really hinders the budget,” Neyer says. “It also is really important to be involved in those early meetings to better understand the project goal. For example, one owner may care a lot about energy efficiency, while another may not. All of these factors impact the estimate.”
“That extends to the construction approach as well,” says Kopf. “The earlier you can get a structural engineer that is qualified involved in the project, the better.”
For example, if you have to hold a spandrel panel in the air because the engineer detailed it that way, it will cost you more money. You’ll save money if you have an engineer who understands both architecture and construction.
“Also, there is a misconception that thinner panels are always cheaper, and that is not always the case,” Kopf explains. “Many times a thicker panel with less steel makes sense, and with the fluctuating prices of steel and concrete, a thicker panel may be cheaper than a thinner panel.”
So be wary of anyone who wants to simply base an estimate on the “thinner is better” philosophy. “If I am given a lot of information and the opportunity to really understand the project objectives, my estimate is drastically different and more realistic than if someone is just looking for a quick number,” says Kopf.
Finally, as Tilt-Up gains acceptance, many people who are new to the method may ask the question, “How much does Tilt-Up cost?” But there is no simple answer to such a complex question, as there are a myriad of variables unique to each project. Providing an accurate estimate requires examining the entire building package, says Kopf.
“Oftentimes people who ask this question are just looking for a number, not a solution,” says Neyer.
“In that instance, if we have half a shot with working with the owner or developer, we’ll offer to help guide them through the planning process to put together a good estimate,” Fischer explains. “In fact, we’ll commit to spending some money on our own to obtain a floor layout and elevation, and – most of the time – the effort results in a contract.”
Tilt-Up’s increasing popularity means more and more projects will and should be converted to this cost-efficient, time-saving and value-provid-ing method of construction. But not every project should be converted to Tilt-Up. By understanding what makes Tilt-Up a good fit for a project, educating architects about the Tilt- Up process and its benefits, and by learning how to provide accurate Tilt-Up estimates, contractors will reap the rewards of building with this proven construction method.
