Six Month Mark of Restoration Shows Progress and Promise!
Redwood Cellar awaits final paint touches before tin roof is laid.
ST. HELENA, CA. October 25, 2007 - Few surprises were unveiled over the past two months of construction but a dramatic change is seen as the plywood base of both the Redwood Cellar and Carriage House roofs are now in place. Painting has begun on the cellar dormers and windows and the meticulous process of stonework is under way on both buildings.
Interior changes are abundant as well. It was discovered that the original foundation, exposed to examine the structural integrity, is unusual in its irregular patchwork structure of volcanic igneous rock. It is quite stable, however, and will only require moderate reinforcement.
The three feet wide by two feet deep pink rhyolite foundation (similar to sandstone), was mined from nearby in the Napa Valley between 1870 and 1871, from a well-kept secret location as was the custom of the day. Sourcing replacement stone today is still a challenge and proves the secrecy of these private quarries.
Inside the Redwood Cellar, large cracks were examined by architect Naomi Miroglio, our restoration specialist. Many of the six-to-ten foot fissures do not pose a threat to the structure itself but will require careful repair to avoid splitting again after the reinforcing earthquake rods are in place (see Renovation Tidbits for details). Another challenge is matching the color of the patch to the original material and 'aging' the final concrete colors and textures.
At ground level, new footings for the main columns in the cellar were poured for the final aspect of this portion of the seismic upgrade. Columns not required for the structural support of the cellar were removed and the atmosphere inside is truly cathedral-like. Watching a supporting column being put in place by a crane operator and foremen is like a bit of steel choreography and should be viewed at a safe distance. As the column is hoisted with the crane at two-thirds of the height of the column, a dance ensues for nearly twenty minutes before it is hoisted onto the four-foot high column support and secured on the column footings or 'embedds' with massive washers and bolts.
Outside, the colors for the trim, flashing and ornamental details are approved, the base primer is applied and the finishing paint touches will provide a dramatic comparison to the way the cellar looked six months ago.
Up on the roof, the plywood base is in place, and the labor intensive removal of stone below the trusses is almost complete. The bond beam is nearly installed and the trusses are resting securely on top.
To meet the demands of historical restoration, the architectural integrity will actually be a mélange of what existed fifty years ago and elements of what the cellar looked like in 1872. For instance, the original roof was a 'shake' roof (near the cupola, some of the shake, secured by hand-forged square nails, is still in view as one climbs the spiral staircase), but tin replaced it sometime in the 1940s and tin will be used for the restoration. The final brick-red color is based on tin found in storage at the winery. Although intermittent rains have set in, huge sheets of plastic are nailed to the plywood for protection. When painting is complete (no chance of paint drips on the new roof!), the new roof will be installed over the next 30 weather-dependent days.
Another blend of architectural elements is seen in the sprayed concrete, or gunite, on the north, east and west sides of the cellar that was applied after the purchase of the winery by Cesare Mondavi in 1943. It was never applied to the south side, and the lime-based plaster 'pargite' and faux brick stenciling from 1872 will be restored. On some sections of the south wall, the worn plaster gave way to the interior stone walls, and will be left as is.
At each window, doorway, arch, base and corners of the cellar and Carriage House, the pink rhyolite stone is being meticulously restored. Simple warm-water low-pressure washing is all that is needed on many of the arches and doorways. Where needed, minimal solutions of environmentally safe cleaning chemicals (absolute minimum used to avoid further deterioration of the stone) will be used to renew the color of the rock.
The masonry work to reinforce and stabilize the window openings requires extreme care to avoid chipping the fragile edges of the stone. Seventeen containers of stone culled from construction on the bond beam are being transformed into replacement pieces for severely chipped stone around window and door arches. The repair pieces, or Dutchmen, are distinguished from small repair patches. While still wet, the clay patches are distressed with chunks of stone to match the aged stonework. Not a high-tech solution, but an artistic addition to our historic structures!
RENOVATION TIDBITS
Interior: Seeming like the game of how many M&Ms are in a fish bowl, one would be hard pressed to guess that 2,257 holes must be drilled to accommodate the earthquake reinforcing rods. 1,800 in the Redwood Cellar and 457 in the Carriage House. The drilling method was patented by the HILTI manufacturing company. Cramped quarters add to the tedious job. Holes are drilled and mesh collars are inserted into the holes. HILTI epoxy is then squirted into the collar and the reinforcing rods are screwed in and cut off.
Exterior: The stone workers involved in this part of the restoration take great artistic pride in their craftsmanship. Mark Murray, of Everest Restoration, explained the difference between a 'Dutchman' and a patch.
Grout color would seem to be a small decision, but several samples were reviewed before the final rose brown and yellow clay mixture was chosen. We think blending wine requires finesse, but this 'blend' is one example of the care the architect and contractor must take to ensure the historical significance and landmark status of the buildings.