Renonvation Contractors Brace Themselves for the Unusual

Renovations always hold surprises, but careful preplanning keeps them to a minimum.

By Lucy Bodilly

No two-renovation projects are alike. While contractors can standardize certain elements of new construction, standardizing a renovation takes more creativity and flexibility. Historic buildings and hospitals are becoming more and more problematic as owners tack on tougher safety and seismic requirements.

Demolition contractor Nuprecon, located in North Bend, Wash., was responsible for the demolition at Roosevelt High School, owned by the Seattle School District. General Contractor is Hoffman Construction, Seattle and the structural engineer is KPFF, which is overseeing the demolition phase and the current construction of the new portion of the school.

Roosevelt was a hodgepodge of remodeling projects already, with the original structure being built in 1922, and additions in 1928, 1960 and 1970. The goal was to save the 1922 structure and some of the walls of the 1928 building for historic preservation purposes. Nuprecon started work on the demolition phase of the project in July 2004 and finished most of the work at the end December.

Hoffman is now building the new structure that will tie into the historic portion of the site. It calls for a new gymnasium, cafeteria and performing arts center.

Demolishing the existing structures was standard fare, but installing shoring and bracing to keep the necessary walls erect was more difficult.

"All the buildings had suffered earthquake damage over the years, so the structural integrity wasn't that great to begin with," said Nuprecon project superintendent Pat Cunningham.

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With the help of a design by structural engineer KPFF, Nuprecon put up temporary shoring to support the 1922 building exterior and floors. Roughly 120 lin. ft. of the three-story brick building was supported only by bracing. When Hoffman's new construction is completed, it will tie into the historic part of the structure.

Work on the Pioneer Courthouse in Portland is also heavily dependent on the bracing and foundation system that was designed by JE Dunn of Portland. Pioneer Courthouse is located in the heart of downtown Portland. Originally built in 1875, the 127 -year old building has not experienced a major earthquake, but in the event that it does, Dunn's work will allow it to withstand an 8.5 magnitude one.

Work includes gutting and reconstructing the building interior, preserving all the original finish work and installing seismic upgrades. Though the walls will have some bracing, the key to the seismic design will be the foundation. Basically the contractor excavated under the building and then poured new concrete columns around the exterior of the foundation as part of the first friction pendulum base isolation system in the Portland area and one of only 50 in the country.

Each column is supported by a base that can move on its own if an earthquake occurs. Foundation beams attach to the columns and then into a concrete base that runs around the building.

Another renovation project with an interesting twist is the work at St. Peter Hospital in Olympia. Designed by Jurgens Giffin Bolte of Portland, work included remodeling and building a new parking structure.

One piece of luck was that departments that needed to be remodeled could be temporarily moved into unoccupied space while the work was completed.

Still, construction workers had to follow the strict protocol for working in a hospital setting.

"Hospitals noticed an increase in the number of patient deaths not related to the specific reason the patient was hospitalized, especially when construction was under way," explained Todd Lee, Sellen project manager. Dust particles in the lungs are the main cause.

The result is an infection control protocol that would make construction workers clean enough to dine with the Queen of England.

Infection controls used at the hospital project called for the use of temporary barriers between occupied spaces and construction zones. Negative air pressure keeps dust from entering the occupied spaces.

"We also made constant sweeps to make sure nothing is being tracked into the occupied space, Lee said. Workers step on sticky floor mats before entering occupied space, or wear booties to make sure dust isn't carried in on their shoes. Vacuuming cothes off before entering the hospital is also part of the process.

Work in the laboratory space is even more controlled, because of the fear that blood borne pathogens may infect the existing space or samples. Workers who bear blood borne diseases such as Hepatitis C may be assigned to a different part of the project, Lee said.

Even air from the outdoors is assumed to be contaminated. When building the pedestrian walkway, Sellen had to place filters over all the air intake systems, to make sure airborne mold or spores did not enter the hospital.

A recent article in Engineering News Record describes the same precautions nationwide and warns that they will become stricter over time.

One of the best time and money savers on any renovation project is planning ahead to decide how to get rid of recyclable materials. At the Villagio, Nupreson scoped out the project ahead of time and decided what to do with the remaining appliances, stove hoods, doors and windows.

The company held a walk through with several salvagers to decide what would be worthwhile to reuse. In all the team came up with 500 windows, appliances, the cedar siding that now has a new purpose.

"We had to piece together about six different buyers, but it was worth it," said Dave Whitely, vice president of marketing for the company. "