San Rafael, CA – During the first week of March, the southern half of the Marin County Civic Center will enter the construction phase of its roof replacement project. A large, white fabric sheet will partially cover that section the roof for the duration of the construction phase, which the Marin County Department of Public Works (DPW) expects to last until early fall.
Workers will soon add an enclosure around the scaffolding in place for the Civic Center Roof Replacement project.
The enclosure material will attach to the scaffolding that was recently installed along the Administration Wing and library dome. The enclosure is intended for public safety and is designed to stop debris, work dust and other particulate materials from leaving the construction area. Measuring from the roof’s overhang, the protective material will reach eight feet high.
Removal of all the old roof material and application of the new polyurethane membrane will be conducted in alternating sections. While one section is undergoing the removal process, a previously exposed section will have the new roofing material installed. For efficiency, a variety of removal methods ranging from pressure washing to hammer and chisel will be utilized. Since some of the methods will produce noise, removal of the old material will take place on weekdays after 3 p.m. to minimize disturbance to the building’s occupants.
The roof replacement for the Administration Wing and the library dome is expected to be completed this fall, at which point preliminary work will start on the northern half of the building, which houses the Hall of Justice. Scaffolding is expected to be installed on the Hall of Justice in early 2019. DPW intends to refurbish the building’s skylights as a separate project after the roof replacement is complete.
The new roofing system will be durable, resistant to fire and high winds, easy to maintain and includes a comprehensive 20-year warranty. The membrane material is expected to increase the safety and longevity of the iconic building. Through extensive testing, the membrane has shown significant color stability and should maintain the historic building’s look for years to come.
Designed by the legendary Frank Lloyd Wright, the 470,168-square-foot building is the largest completed public project of the architect’s career and is listed in the National Register of Historic Places. The Civic Center is characterized by a concrete roof with distinctive blue coating and stylized ornamentation. Dating to the original construction more than 55 years ago, the current roof has four layers of recoating and patchwork. Despite several repair projects over the years, the membrane is fracturing and peeling, resulting in leaks and substantial fading of the color.
In 2015, DPW sought the expertise of independent architectural specialists at Wiss Janney Elstner Associates, Inc., to assess the roof. The company determined that repairs were no longer a solution and the 220,000-square-foot roof needed to be replaced to preserve the historic building.
The new roof will be one of the largest construction projects on the Civic Center since it was built in the 1960s. Not accounting for inflation, the Civic Center’s Administration Wing and Hall of Justice originally cost approximately $14.6 million to construct.
On September 26, 2017, the Marin County Board of Supervisors awarded a $17,842,799 contract to Arntz Builders, Inc., a Novato-based company, to direct the project. Rainbow Waterproofing and Restoration Company, which specializes in historically significant landmarks, will handle the removal of the old roof and the construction of the new one.
The project is being funded by the Capital Improvements Fund. The County’s Department of Finance raised the necessary money by refinancing Certificates of Participation, which essentially are bonds for municipal and government agencies, in 2015 when market conditions were favorable.