Photos courtesy of Arbor Building Group Inc., Lafayette, Calif. The beginning of the roofing project

Park Station Condominiums is a four-story, 99-unit condominium complex in South San Francisco, Calif. Adjacent to the Bay Area Rapid Transit Station (BART), the complex also includes parking for up to 121 vehicles, fitness facilities and media lounge.

When planning the $27 million project, city officials wanted a distinctive roofing material that did not require much maintenance. A standing-seam metal roof system was chosen, and Arbor Building Group Inc., Lafayette, Calif., the project's general contractor, asked Lefco Inc., Sunnyvale, Calif., to bid the project as the roofing subcontractor.

Installation

A Custom-Bilt Metals roof system was chosen for the project, which required 85 squares of metal for one building and 116 squares for a second building.

The buildings were located close to electrical lines, making it more difficult to move materials to the roofs.

"The project documents required a generic standing-seam metal roof system," says Mark Ebner, principal of Arbor Building Group. "Lefco proposed a product provided by Custom-Bilt Metals, and the project team approved it. The product could be ordered in advance and shipped to the site ready for installation. This was a plus because we had a tight schedule.

"Additionally, the material could be rolled and bent into lengths that, though more difficult to ship, would eliminate cross seams in the finished product," he continues. "Also, pre-finished material was available to create the many custom shapes and fittings the roof's design required."

The roofing project began in January 2008. Lefco first installed the Grace Ice and Water Shield® to help waterproof the building while other trades finished their work. At the end of March, Lefco began installing a Custom-Bilt Metals Titan® Cap Seam CS100 roof system, which consists of snap-on batten seams that lock individual panels in place. The roof system was installed over a self-adhering membrane.

Lefco also fabricated and installed counterflashings, other parapet capping and gutters, using the same materials used for the roof panels.

Facing challenges

When possible, a crane was used to hoist materials to the roofs.

Weather caused some problems for the roofing crew during the project.

"Wind, rain and cold conditions were major obstacles during installation," says Bill Leffler, president of Lefco. "We were under pressure to make the building watertight. We could not install the panels on the steep-slope roof areas when there was wind and rain, and we could not leave the unfastened panels sitting on the roof until the next day. We had to move panels constantly, taking them on the roof when installing and then off the roof overnight."

However, the company met this challenge and overcame it.

"We had to plan daily for safety staging, rigging and working through these natural contingencies," Leffler says. "Through excellent communication between our crews, we were able to safely and efficiently install the roof system."

The standing-seam material was rolled off-site and shipped to the project location. Getting the materials to the job site also provided a challenge.

"There were no parking areas, and we could not set up on the two side streets because of continuous traffic, as well as requirements from the city of South San Francisco and BART," Leffler says. "Because of the building's height, we had to use a crane to move the panels onto the roof."

The roofing project progresses.

However, even crane use had its limits.

"High-voltage electrical lines by the local utility company ran parallel to the building and restricted the metal's placement on the roof by crane," Ebner says. "In some cases, it was easier to have the workers hand the 20-foot-long pieces of metal up to the roof using the scaffold system. Also, because the site was adjacent to a regional transportation hub&emdash;BART&emdash;delivery hours were restricted."

Another obstacle was a radius corner on the smaller building that had to incorporate various angles.

"Each metal panel had to be made to taper from the standard width down to a narrow width to create the uniformed fan effect," Ebner says. "This was a success because of careful coordination with the metal manufacturer."

Various other roof features complicated the roof system fabrication and installation.

"The roofs included dormers and different roof levels, and all this had to be engineered, fabricated and installed to create the look of a professional application and also be watertight," Leffler says.

Working safely

The finished product

"Safety was a major concern during this project because the building is four stories tall with steep-slope roofs all around," Leffler says. "The slope of the roof is about 5-in-12, which makes working on the surface a task."

The company used full-body harnesses, safety belts, supports, ropes and tie-offs to meet Occupational Safety and Health Administration requirements.

Arbor Building Group provided pipe scaffolding around the entire project.

"Scaffolding was used as fall protection and a working surface for installing windows, stucco, metal flashings, gutters, caulking and the roof system," Ebner says. "When the scaffolding was removed, Lefco and other subcontractors used body harnesses and lanyards as part of their fall-protection system."

A classic, contemporary look

Leffler says finishing a challenging project in difficult conditions was satisfying.

Park Station Condominiums, South San Francisco, Calif.

"Meeting the tight schedule even though installation conditions were poor for the majority of the project was rewarding," he says. "We finished the project without any leaks, and people voiced their approval of the roof's appearance."

"The project owner and local city planning department wanted a look that was both classic and contemporary," Ebner says. "The metal roof system provides a clean, contemporary look but also a classic, old world appearance. The owner and planner were happy with the look and achieved their desire with a metal roof system."

Krista Reisdorf is Professional Roofing's director of online communications.

Project name: Park Station Condominiums
Project location: South San Francisco, Calif.
Project duration: January 2008-April 2008
Roof system type: Metal
Roofing contractor: Lefco Inc., Sunnyvale, Calif.
Roofing manufacturer: Custom-Bilt Metals, Chino, Calif.