Historic Napa Winery Standing Tall Again

Restoration of quake-damaged Trefethen barn may be complete in a year

by Andrew Adams
The historic winery building at Trefethen Family Vineyards, damaged by an earthquake that struck south of Napa, Calif., on Aug. 24, 2014, is standing much straighter following the first stage of a major repair project.

Napa, Calif.—The first phase of restoration and repair of the historic winery at Trefethen Family Vineyards is nearing completion with the building already standing straighter.

The structure, which dates back to 1886, suffered significant damage in the Aug. 24 earthquake that occurred just south of Napa, Calif. While the building had been stabilized in the days immediately after the quake, there was some uncertainty about whether it could be saved or restored to its former historical appearance.

The winery’s president Jon Ruel told Wines & Vines that after assembling a team of contractors, engineers, architects and historians the first goal of the restoration project involved getting the building back into vertical alignment. After the earthquake, the upper floors of the structure were leaning precipitously to the west by nearly 4 feet. The exterior of the structure was reinforced with a framework of stout metal beams, and the interior was reinforced with “cribbing,” or stacks of timber as thick as railroad ties and large jacks.

‘Chiropractic’ treatment to get building back in shape
About a month ago work began to get the building realigned. The process involved tightening cables anchored in the building’s cement foundation and in specific spots on the walls. The initial hope was to get the building back into alignment at a rate of about 1 inch per day. “Well, the building reacted positively and quickly, and most of the 40+ inches needed was achieved in just one day,” Ruel said. “It truly felt like a miracle.…It's like we did chiropractic work, and you could almost hear the building say ‘Ahhhh, that feels better.’”

Ruel said the experts on site were also impressed by the elasticity of wood structures snapping back in to place. Trost Jacking and Heavy Moving in Bay Point, Calif., pulled the building in to place and continue to work on the structure. To keep the building straight, the engineers adjusted the cribbing and jacks and added steel beams to the external frame. “Anyhow, that is the first phase, nearly complete, but there remains much work to be done,” Ruel said.

Santa Rosa, Calif.-based ZFA Structural Engineers, which helped build Dominus Estate, Alpha Omega, Quintessa Vineyards and the seismic retrofit at Chateau Montelena Winery is the structural engineering firm on the project. Executive principal and CEO Kevin Zucco said despite the building being righted into place, “A large percentage of the structural members were damaged during the earthquake, and the structure remains in a very vulnerable state.”

He said ZFA used a 3-D scan of the building created by the construction team to build a model of the structure’s framing elements. “It was very interesting to see the building’s damaged shape overlaid with the true structural model,” Zucco said.

ZFA’s plan to strengthen the building includes reinforcing the existing walls, incorporating a new steel frame into the architectural design and upgrading the foundation and anchorage. “There are still too many variables involved in the design to accurately predict a completion date, but the building stabilization process was completed much quicker than anticipated,” Zucco said.

trefethen earthquake barn
While restoration work continues on the historic structure (above), the winery is hosting guests elsewhere on the property.

Preserving history
The plan is to not only repair and strengthen the building, but to do so in a way that maintains the historic nature of what is the only remaining three-storey, timber-framed winery building still in use in California. “All this work is being done in consultation with our preservation architect to ensure that we maintain the historic integrity of this special building,” Ruel said.

“The family is really delighted that we will be able to maintain so much of the original look and feel,” he said. “The responses from our colleagues, customers and friends after the earthquake only furthered our conviction that we should do everything we can to preserve this historic landmark.”

The entire cost of the project is still being determined. Ruel said earthquake insurance is expensive for a modern building and “near impossible” for a building that’s 129 years old.

As the restoration work continues, the winery has been hosting visitors in a tented pavilion the staff is calling “The Conservatory.” While the “pop-up” tasting room has proved quite popular, Ruel said it is temporary and the Trefethen family is planning to convert an existing house on the estate into a tasting room, although there’s no set date on when that would open.

Posted on 05.05.2015 - 13:34:31 PST
Very Interesting, I'm so glad the building is successfully being saved.

Posted on 05.12.2015 - 07:38:56 PST
It would be nice to know that Trost Jacking and Heavy Moving is the structural mover that was on site and responsible for pulling the building back.

(Editor's Note: We added that info to the story, thanks.)