To prepare the (Plymouth Church) sanctuary for the new organ, Rafn lowered the existing chancel, requiring demolishing the existing structural concrete slab and replacing it with a new one. To improve the acoustics, Rafn raised the height of the ambulatory ceilings and installed curved glass fiber-reinforced gypsum panels.
Halfway through the project, Rafn noticed cracks in the existing glulam beams that supported the sanctuary roof. Review by structural engineer Swenson Say Faget concluded that the beams were under-designed by nearly a factor of 10 and that the roof structure was gradually failing.
The engineers recommended the addition of steel king posts and tension rods and that the roof beams be converted into a truss system, adding visual interest as well as strength. Costs and impacts to the schedule were kept to a minimum by carefully refining the methods for installing the tensioning.
The project also involved installing CMU mass walls on three sides of the sanctuary along with ductwork for the organ blower and de-stratification ductwork below, new oak flooring on the chancel and new Italian floor tile in the sanctuary. Existing walls were painted, the stained glass was cleaned, lighting was replaced with custom ornamental wall sconces, and a halo-shaped fixture that was assembled on the ground was hoisted into place.
The organ, handmade by renowned organ maker C.B. Fisk in Gloucester, Massachusetts, is called the Opus 140. It has 3,398 metal and wood pipes and is the focal point of the sanctuary. Rafn worked with C.B. Fisk and On Sight Access to build the three-story case with tall swinging maple panel reflector screens that double as mass walls and doors to storage rooms surrounding the organ.
The project budget and schedule were affected by the need to redo the roof, but the client is pleased with the finished structure. There were no time-loss or medical injuries during the 6,168 hours worked.
ABC 2016 Excellence in Construction Award Winners
Historic Preservation/Restoration: Plymouth Church sanctuary-Rafn Co.
Architect: LMN Architects
Engineer: Swenson Say Faget
Owner: Plymouth Church
ABC members: Crystal Soda Blast; Clark Nuber; Propel Insurance
Pike Place Market / / 08.06.14
This $68 million seismic renovation improved safety of the market facilities without changing the market's character.
Proposed rules for URM Buildings / / 02.16.17
The owner of the Whitworth Apartments on Capitol Hill is planning a seismic retrofit in advance of new city rules that could require retrofits for unreinforced masonry buildings.
Sherman Clay Building Renovation / / 07.09.14
SSF was the structural engineer for the $3 million upgrade of this 1926 Neoclassical, historic building.