NAPA — Tens of thousands of Napans have had to straighten out their daily lives since the August earthquake. So, too, has the Trefethen Family Vineyards – only literally.
Since the quake of Aug. 24, Trefethen’s historic tasting room building, a three-story redwood edifice erected in 1886, has listed 4 feet to the west, its still-vertical upper half perched atop slanted walls and loosened planks below.
Amid the placid backdrop of grapevines, the leaning Eshcol/Trefethen Building stands – aided by steel buttresses sunk into 12 feet of concrete – as a reminder of the quake’s violence.
“We were all in such shock from the earthquake, it didn’t seem real. Still doesn’t,” Hailey Trefethen, who works in the family’s winemaking and viticulture operations, recalled Wednesday. “It looks more like some painting that Salvador Dali did.”
Now, engineers and winery staff say work to straighten the damaged Eshcol/Trefethen Building may begin this month, the prelude to a repair program expected to last as long as two years. The cost of the overhaul is not yet known.
Before the earthquake, the Eshcol/Trefethen Building, which is listed on the National Register of Historic Places, housed a tasting room at ground level and barrels upstairs. Trefethen has since consolidated all barrels into a separate, undamaged building on the grounds, while guests sample wines inside a large banquet-style tent with views of the surrounding 400 acres of vineyards in the Oak Knoll district north of Napa.
The 1886 building’s flexible wood construction allowed it — barely — to endure the West Napa Fault’s magnitude-6.0 jolt, but not without damage to its support structure, according to the engineer consulting Trefethen on the repair plan.
“Some columns that were continuous through the floors fractured,” said Kevin Zucco, chief executive of ZFA Structural Engineers in Santa Rosa. “The posts themselves, top and bottom, didn’t have hardware holding them to the foundation or the beams they’re supporting. They rocked over and just happened to stay there by gravity alone.
“It was one more aftershock or one more seismic wave away from being disastrous.”
Even with the resulting tilt, however, the winery building held, and within two weeks a set of vertical and diagonal steel I-beams was erected to form a brace against the west wall. The temporary buttress has bought Trefethen time to craft a repair plan, for which equipment was to be brought to the winery starting this month, according to winery president Jon Ruel.
The first phase of repair will involve slow, methodical hydraulic jacking to tilt the structure back to a vertical position, a process Ruel said cannot proceed at more than an inch per day to avoid weakening other parts of the structure. Fully straightening the building is expected to take three months.
As straightening continues this spring, ZFA as well as a historic architect and winery leaders will work on a final repair plan, which Trefethen will submit to Napa County for a construction permit. The overhaul is expected to last one to two years, Hailey Trefethen said.
Storage tanks that had occupied the second floor have been removed, and that floor will be put to a different use that will place less weight on the structure, according to Zucco.
A major goal is to schedule repair work to avoid disrupting growing and harvest activity at Trefethen, an estate winery that uses only grapes grown on-site or at a family-owned 40-acre property 2 miles away in the Mayacamas foothills.
Despite the quake, the winery has operated largely as normal, helped by the quake’s timing just days before the 2014 harvest – a quirk Hailey Trefethen said prevented a costly loss of wine that could have been stored inside the historic building had it occurred later. Ruel said the number of visitors has remained close to the levels of a year ago, despite a switch to appointment-only tasting due to the banquet tent’s smaller space.
Still, the impending start of repairs had Hailey Trefethen eager to turn a page in her family winery’s recovery.
“Everyone is ready for action, as are we,” she said while looking through the chain-link fence surrounding the building. “The next couple of weeks will be exciting.”
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