At five stories, Kraus-Anderson’s new headquarters building has reached its full height. But it won’t be the tallest point on the mixed-use KA Block for long.
Vertical construction has commenced on H.Q., the 17-story apartment building along Portland Ave., adjacent to the KA office building. With now two buildings going up simultaneously in close proximity, members of each team reported on the progress.
Q: Construction of H.Q. is now underway. What milestones or highlights are planned between now and year end?
CHRIS DOKKEN, PROJECT MANAGER, H.Q. APARTMENTS: We are currently pouring Level 5 and expect to have Level 8 complete by the end of the year. In addition:
• An exterior hoist will be installed at the end of the month for vertical transportation.
• Level 1 exterior enclosure is scheduled to start mid November and we expect enclosure to be installed at Level 4 by the end of the year.
• Window and door installation at Level 1 are scheduled to start at the end of the November. We expect windows and doors to be installed at Level 3 by the end of the year.
Q: You are scheduled to be pouring concrete through the winter months. How does cold weather affect pours? What preparations are you making to maintain productivity in the cold winter months?
CHRIS DOKKEN: Cold weather concrete pours differ from those in the summer months in a number of ways.
• Concrete mixtures contain additives that accelerate the cure time.
• The concrete mixture is delivered to the site warm prior to the pour.
• The area under the slab being poured is enclosed and heated so the concrete is poured on a warm dry surface.
• After the pour and finishing is complete, the concrete is covered with thermal blankets to contain heat while the concrete cures.
• If snow is predicted after the pour, snow tarps are also installed over the thermal blankets so the snow can be lifted off the surface and disposed of off site.
Q: At this writing, the KA office building is not yet enclosed. What preparations are being made for winter?
CHAD REMPE, SENIOR PROJECT MANAGER: With the exception of days with extremely cold temperatures work will proceed uninterrupted in the winter months by using temporary enclosures and heat.
TERRY COLEMAN, PROJECT SUPERINTENDENT, KA OFFICE BUILDING: We are putting up poly sheathing. Each floor also has a 1 million BTU space heater.
Q: While the H.Q. is being constructed of post-tensioned concrete, the KA office building is structural steel. What’s the rationale for the structure choices?
Steel structure offers first cost, schedule, and future design flexibility advantages over concrete for the office building. For the taller hotel and apartment projects where sound transmission is of greater concern, concrete is a better choice. Additionally, concrete provides a more efficient structure that requires less floor to floor height to get same clear height if designed using steel. This ultimately yields a higher GSF to skin ratio meaning you get more leasable/useable GSF per area of exterior enclosure; for the 17 story H.Q. Residential Tower this could mean the difference between a 190-foot building designed using steel vs a 180-foot building designed in concrete.
Q: Since topping off in October, what have been the progress highlights on the KA office building? What are the highlights between now and year end?
CHAD REMPE: Slab on metal deck is complete; Spray applied fireproofing is in progress, with architectural precast concrete exterior panels and exterior glazing scheduled to begin in December.
Q. What trades are currently at work in the KA office building?
• MEP rough in work
• Steel work finishing up on fifth floor
• Concrete pours are being completed on the top floor
• Some of our own carpenters/laborers are self-performing temporary enclosure work.
Q: What are some of the Lean Construction processes being incorporated into this project?
TERRY COLEMAN: BIM, Prefabrication, Daily huddles, weekly work plans, pull planning, PPC (Percentage Planned Complete, defined as the extent to which a plan is an accurate forecast of future events. Think say/do ratio.)
Q: Talk about the innovation in the HVAC material being used in the project.
TERRY COLEMAN: HVAC work is incorporating CoolDuct product material instead of typical metal. It is lighter, easier to handle, pre-insulated. It’s manufactured in Wisconsin, so locally sourced.
Q: Another Lean process is the use of the double gating in some work areas. Explain that.
TERRY COLEMAN: The double gate material landing zones used along the edge of the building allow workers to work more efficiently. They can remove one of the gates to receive a load from the forklift and then replace it before opening the interior gate to access the load. and don’t have to hook up to a safety harness. Ethan Laubach is our on-site safety coordinator, here two days a week. Ethan and I are testing out “Primal Safety.” Primal Safety is focused on reinforcing good behaviors, encouraging work readiness, holistic health and safety, and relating risk behaviors back to repercussions to the workers family if something had happened to them.
Q: Any other Lean approaches you want to mention?
• We’re using Touchplan software instead of Post-It notes for the subs planning meetings. We do a weekly work plan with detailed commitments for the week. The six-week look-ahead details manpower, equipment, long lead time items; and information that will be needed to put work in place six weeks from now. Going out further than six weeks, the Touchplan simulates Post-It notes, and illustrates the sequence and rough time frame materials and personnel will be needed.
• The white crane on Eighth was used to set the steel. It has recently been modified to prepare it to hang precast, which is due onsite in December.
• We’re using a Lull instead of a skip to move materials between floors. It is less expensive, we own the equipment and more flexible use on the site.
• Plumbing units called a bathroom groups were manufactured and assembled off site, part of a lean process. The materials are assembled in a controlled environment, at table height.
• Kitting is another lean process in use. An example is Hunt Electric’s innovation- a little cart with the drilling and water/cooling apparatus, all self-contained. Saves time, efficiency. A kit should include everything a person needs to complete the task including any PPE the task might need.
• The poly frames are being assembled on the upper floor and we’ll let gravity help us take them down.
Q: In addition to the office and apartments, the KA Block development will include The Elliot Hotel and Finnegan’s brewery buildings. How are you coordinating logistics and schedules as multiple projects are simultaneously under way within the block site?
CHAD REMPE: Currently we have an average of approximately 80-100 people on working on site. Each project is being managed individually by each of the project teams. That said, there is daily communication between the teams to coordinate site safety, deliveries, and site logistics.
Q: The hotel and brewery components of the KA Block aren’t scheduled to start until spring. What preparations are happening on the footprints of those sites in the meantime?
CHAD REMPE: The Hotel and Brewery are currently scheduled to start construction in April 2017. Our team is working with KA Development, Wilkinson Corporation, and ESG Architects to finalize design. Our main focus right now is coordinating shafts and sleeves that penetrate the Level 1 slab to insure quantity, size, and layout meet the needs of the current Hotel and Brewery designs; these areas are currently scheduled to be poured within the next two to three weeks.