Rafn Co.
Cadillac Hotel
Architect: Stickney Murphy Romine Architects
Owner: Historic Seattle
ABC members: Benjamin Asphalt, DeBolte Plumbing & Heating, Evergreen Concrete Cutting, Ketchikan Drywall Services, Ralph’s Concrete Pumping, SME Inc. of Seattle
The 1889 Cadillac Hotel was severely damaged in the 2001 Nisqually earthquake and was scheduled for demolition before being bought by Historic Seattle.
Although engineers initially recommended demolition as the most cost-effective option, Historic Seattle persevered with shoring the building until it could be restored.
Rehabilitation work included repairing and restoring the exterior masonry walls; seismic reinforcement consisting of steel brace frames on the east, west and south elevations; reconstructing parapets; wall ties; additional roof and floor sheathing; and new interior shear and load bearing framing.
In addition, Rafn installed a new roof, skylights, storefront windows and doors, and restored the existing wood-frame windows.
The Cadillac was vacant for nearly three years before renovation started and the only work done was shoring the masonry walls to ensure public safety. Deferred maintenance before the earthquake resulted in sagging wooden floors and roof joists, and rotting roof members. Also, a set of interior stairs had been removed, reducing the load capacity and weakening the building.
Making the Cadillac structurally sound again required a complete seismic retrofit. Unfortunately, the building had originally stood right at the edge of tidal flats and the sandy soil conditions required excavating 14 feet to place the seismic frame footings.
Crews used 60-foot steel beams to raise and level each floor, and installed new support columns. After the steel beams were placed and the first floor completely shored, hydraulic jacks were placed approximately 4 feet apart, and the entire second and third floors were lifted together.
With the floors leveled, crews installed additional steel beams as seismic bracing and reinforced the existing walls with CMU and historic brick.
Conserving the historical character of the Cadillac entailed collecting fallen brick to reuse, and removing and restoring wood-frame windows and doors as well as much of the window and door trim, wainscoting and stair rails.
There were no time lost accidents on the project, and only one recordable incident for bruising abrasions and minor muscle strain.