Capitol dome cleaning and preservation work begins soon

Photo of workers cleaning the dome in 2012

Workers last performed cleaning and preservation work in 2012.

Building access and noise impacts will occur during the project

OLYMPIA -- Masonry preservation work on the Legislative Building, which includes cleaning, will begin Sept. 4. The state Capitol Campus building also is frequently referred to as the Capitol Building.

The preservation work will be done in three phases:

  • The central dome atop the building
  • The band that circles the building beneath the dome, including the parapet walls
  • The plaza area

“There is a limited 'weather window' for work on the building for both project success and safety,” said Bill Frare, Enterprise Services Assistant Director for Facility Professional Services. “We are confident there is enough time to finish work on the dome this fall, but we may have to do the lower sections next year.”

Enterprise Services has contracted with a consulting team and masonry firm to perform the work following a competitive bidding process:

  • SHKS Architects of Seattle completed design work for the project in August, and will work on an ongoing basis to develop solutions for repairs as more is discovered about the building’s condition during cleaning.
  • Pioneer Masonry of Seattle will perform the cleaning and restoration work.

September work

During the first week of September, crews will begin mobilizing and will be testing a cleaning product on the building’s sandstone to double check that it won’t cause damage and will be effective. Crews will be working with Portland-based conservators ARG, a firm that Enterprise Services contracts with.
“The conservators’ expertise is vital to each project performed on a campus historic building: Considerable science is involved in the preservation and cleaning materials like sandstone -- and the science as well as best practices are continually evolving,” Frare said.
During the second week of September, the actual cleaning and preservation work is scheduled to begin.

Time frames for the work are weather dependent and subject to change.

Noise and access impacts

As crews work on the building, there will be impacts to:
  • A small number of parking stalls
  • Exterior areas of building periodically will be closed for safety, including the building’s stairs and front entry
  • There also will be slight noise impacts

Work is planned to minimize impacts during business day as much as possible.

Preservation cycle

Masonry preservation work on the Legislative Building’s dome, which includes cleaning, is generally performed about every seven years. The dome’s darkened appearance is from a lichen that grows on the sandstone. The growth is a natural occurrence in the northwest and typically reappears within five to six years of cleaning.

In early 2018, the Legislature approved $3.4 million for masonry preservation work on the dome.

Learn more

Learn more about preservation work on this historic building and find work updates on the building project web page.