Great Heights
44 Monroe Rises Above Phoenix

By Scott Blair

The 34-story residential tower 44 Monroe rises above Phoenix streets teeming with construction activity. Upon completion, it will be the tallest residential property and the third tallest building in Phoenix.

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While Phoenix had made recent strides in developing its downtown core by bringing in sports facilities, convention centers and schools, it has lacked what many observers felt was essential in forming a vibrant urban community: multistory residential.

The $75.6 million 44 Monroe tower will go a long way toward changing that. Named for its address at First Avenue and Monroe Street, the 34-story building will add 532,000 sq ft of residential space to downtown Phoenix.

Upon completion in spring 2008, 44 Monroe will become the tallest residential building in Arizona.

"The turnaround that's going on in Phoenix depends largely on people actually staying here on nights and weekends," says Rick Fria, president of the Fria Co., a Carefree, Ariz.-based project management firm representing Grace Communities, the project's Scottsdale-based developer.

A long-vacant 11-story office building stood at the small, quarter-block-sized site. The developer had planned to turn this existing structure into roughly 60 condominiums, but in order to maximize the site's potential, the new 202-unit tower was chosen, Fria says.

Demolition began in late 2005 and after the building was totally removed, work on the foundation of 44 Monroe began in February 2006.

The foundation system consists of 52 caissons ranging from 5 to 8 ft in diameter and 55 to 80 ft deep; grade beams; and an 85-ft-long, 64-ft-wide by 12-ft-deep concrete core foundation mat, says Andrew Klem, project engineer with the Phoenix office of the Weitz Co., the project's general contractor. The caissons support the building above through friction with the surrounding soil because bedrock was too deep.

"There are nine caissons located under the north basement wall, which is actually a transfer beam/girder, as the columns above are offset from the caissons below," Klem says. "The remainder of the caissons directly support columns or the foundation walls, and in some places both."

One level of parking is below-grade, while additional parking will take up the second through seventh floors of the structure.

Rudy Erdmann, senior project manager with Weitz, says that the most complicated part of the project has been the parking levels. "There was so much steel [rebar] congestion, especially in the heavier columns and slabs," he adds. "The structural engineer, [Phoenix-based] PK Associates, was onsite virtually full-time directing traffic and answering questions."

Phoenix-based subcontractor Suntec Concrete used 6,000 psi concrete for the floors and 10,000 psi for the columns. "With the help of Wietz and Suntec, we developed a cost-effective concrete tower structural system comprised of an 8-in.-thick post-tensioned flat plate supported on 26-in.-square concrete columns," says Cliff Paul, principal of PK Associates.

After starting out at a floor every 12 days, crews found their rhythm and have been recently pouring a floor every week, Erdmann says. The final floor was poured early this month.

"We need 34 concrete trucks per floor, and they cue all the way around the block," he says. The trucks unload two at a time into the concrete pump, which lifts it with the aid of an auxiliary pump located on the floor that is being poured. A swing-arm spout takes the concrete to its final destination.

"It's a slick, organized system that has worked well," Erdmann adds. The condominium units range from 780 to 4,800 sq ft and range in price from $400,000 to $3.2 million penthouses. The variety of sizes required four different floor plates throughout the tower, each requiring adjustments in the concrete forms.

Suntec devised a forming system specifically for the project, Erdmann says.

"Instead of taking separate forms, erecting them, tying them together and then pouring concrete, they did an entire wall system of forms so that the entire wall could move," he adds. "You could put your rebar in, put the forms back and then pour the concrete, all in one step, saving three days per floor."

The tight urban site adjacent to major light-rail construction prevented all but a miniscule area for staging. "The key to staying on schedule on a job like this is managing the vertical transportation, which includes the crane and the man and material hoists," Fria says. "Material has to come on an as-needed basis and it has to go right up on the crane to where it's going to be used. Weitz has done a good job of managing that."

The building's design initially included five metal fins that started at the base and then continued up to the top and arched over the top of the building, says Sharon Rissling, project manager with San Diego-based Tucker Sadler Architects, who were brought in to complete the job after the original architect dropped off the project. "We subsequently had to cut back some of that due to the high cost of product in the steel especially," she says. The fins will now be formed with metallic paint rather than metal to provide the building's iconic look.

It was important to bring a well-tested and proven exterior skin system in order to prevent water and acoustical intrusion into the residences, Fria says.

"These two elements are usually where class-action litigation in condos comes from, but it doesn't have to be that way," he says.

Glazing contractor Walters & Wolf's Phoenix office installed a system designed by Concord, Ontario-based manufacturer Toro Aluminum. "In our engineering and specifications we incorporate the requirement to do field tests once it was installed on site," Fria says.

During the test, 12 lbs of negative pressure are applied to test portions of glass in specially sealed areas. "On the outside we sprayed the entire one-story glass segment with water and with that kind of negative pressure on the backside, if there was a leak it would show up, guaranteed," Fria adds.

The first two of five tests were recently completed with no leaks detected.

Key Players

GC: The Weitz Co.
Architect: Tucker Sadler Architects
Developer: Grace Communities
Owner Representative: The Fria Co.
Structural Engineer: PK Associates LLC
Subcontractors: Suntec Concrete; Wilson Electric; Tri-City Mechanical; W.D. Manor Mechanical; Powers Steel & Wire; Walters & Wolf; Arizona Partition