It was the Centennial Celebration of the National Park Service (NPS) and I spent the week immersed in the University of Oregon's Pacific Northwest Preservation Field School at Mt. Rainier National Park. The subject of our session was the preservation of a deteriorating workers' cabin built by the Civilian Conservation Corps (CCC) in 1937. From sunrise to sunset, we were engaged in hands-on work under the guidance of professional craftspeople and preservationists with Socratic discourse in the field and formal presentations by experts. We camped in tents along the Nisqually River at Longmire Village and socialized and dined together as a group at Longmire's historic Community Building (1927).
This is particularly interesting for me because my grandfather worked for the CCC when he was a young man in living in the Midwest. Following the Great Depression, the CCC was established as a way to put people to work and build our nation's infrastructure. Men who volunteered worked six days a week, were given meals and lodging, and paid $30 per month but they were only allowed to keep $5 per month. The remaining $25 was sent home to their families. The Corps operated loosely like the military and many of its rank and file were WWI veterans. My grandfather would have gotten a kick out of seeing me doing construction work on a CCC project
Monday, August 22nd:
Discussion this morning was with historical architect Jared Infanger about the history of Longmire Village. Longmire Spring was established in 1883 and a park concessionaire from 1888-1920. NPS development of the village began in 1920 and eventually bought the claim in 1939. It was designated as a historic district in 1991 with a period of significance from 1926-1942. Mt. Rainier National Historic Landmark District was designated in 1997 and is significant, in part, because it is an intact example of NPS master planning and landscape architecture.
For our on-site activity, I joined Sterling Holdorf and Lonnie Maize, preservationists from Channel Islands National Park, to work on the heavy timber lookouts of the southwest face of CCC Workers Cabin L125. The lookouts supporting the roof overhang were 10”x10” beams. Most were rotted from the exterior and missing a significant amount of material. After assembling scaffolding, we removed two lookouts, one at the peak and its neighbor to the northwest.
The peak lookout was 32” in length and showed at least 50% decay which drove the decision to replace it in-kind with a new timber. Our selected timber even had a small amount of wane in the same corner as the original. We reviewed scans of original drawings which indicated that the lookout was designed to be 4’-0” in length. To determine if this was the case we looked at photographs. A photo of the cabin under construction showed the lookout extended about 3 inches from the face of the barge rafter, confirming that the 32” overall length of the original was, in fact, unmodified since its installation.
Nick Vann from Washington State Department of Historic Preservation gave an evening presentation about how historic buildings fit into model codes. We talked about the primary issues with historic buildings are ADA accessibility, life safety, energy efficiency, and seismic upgrades triggered by addition, change of occupancy, or structural modification. We also discussed the significant cost benefits of regular maintenance over deferred maintenance. Historic preservation provides economic benefits to communities including increased property values through reuse rather than blight, tourism, tax credits, and job creation.
Tuesday, August 23rd:
Work continued in the morning session cutting, sanding and installing our new lookout at the roof peak as well as cutting the second lookout. The ridge beam had a fracture along its underside so we glued and clamped this back together prior to installing the replacement lookout. The new timber was date stamped to allow future preservationists to know its age. Significant rot was discovered in the heavy timber column under our second lookout, so preparations were made to cut and replace a portion of it with a lap joint and epoxy.
A piece siding had been damaged at the roof peak and we spent time gluing and clamping its pieces back together to allow the plank to be reinstalled later.
In the afternoon, I switched groups and began working with Suzana Radivojevic on wood science and wood identification. We reviewed samples of hardwood and softwood species and their relative shrinkage, both radially and tangentially, and specific gravity properties.
Growth rings are the result of light spring growth and dark, late-season growth. Quick growth equates to deeper rings while slow growth and old growth have narrower, tighter grain. Over the long life of the tree, some of the sapwood toward the center may develop into structural heartwood. Extractants of some wood types, like cedars, prohibit fungal or insect infestation. Wood is composed of hydrophilic cellulose and hydrophobic lignin. Various types of fungus may attack either component but in the Northwest we typically observe brown rot which eats away at cellulose. Some conifers, such as pine, have resin or pitch which the tree uses to protect wounds. Presence or absence of cellular resin canals can be used to help identify wood type.
We examined CCC cabin L123 for types of wood and evidence of decay. Foundations in direct contact with the ground were subject to much decay from fungus and insects such as termites and carpenter ants. The adjacent paved road directed seasonal meltwater toward the cabin, exacerbating decay.
Our evening lecture was about the preservation of North Head Lighthouse presented by Alex McCurry of Washington State Parks. Two phases of work over about four years will restore the sandstone base, structural steel, ball and vents at the roof, and original windows that were removed and covered up by the Coast Guard, which owned the building until 2012. Original drawings and daymarks are available to guide the fenestration, paint, and stone restoration.
Wednesday, August 24th:
Architect Tim Mitchell presented his work on the preservation and restoration of Paradise Inn at Mt. Rainier, followed by a field trip and tour of the building. The Inn was completed in 1917 and was initially weathered-in by its construction crew in 60 days. It has a lodgepole structural system, a steep roof and gable dormers.
In the '80s, concrete shear walls were added in the main lobby to reinforce the building. In the most recent renovation these were removed and new structural upgrades were incorporated into the chimneys. Stones were removed and numbered, shear walls and post-tensioned, cantilevered columns were added, and stones were reinstalled in their original configurations. Logs and half logs were used to masked the increased thickness of the shear walls.
Cables with turnbuckles were used to straighten the structural frame of the east wing which was 12” out of plumb. Some gable dormers were altered to shed dormers because snow loading pulled them off the building. Copper flashing was added to exterior horizontal surfaces. Alaskan Yellow Cedar was chosen for new logs on the exterior, for long-term durability. Douglas-fir was used for new interior logs.
Amy McAuley of Oculus Fine Carpentry gave us a tool sharpening demonstration. For window repair, Amy uses only hand tools. Sharpening chisels involves a long process of preparing the face and bevel surfaces by honing them on diamond stones of decreasing coarseness followed by polishing with finer grades of diamond oils. Some chisels have a single bevel at 25°, some employ a secondary bevel at 30°. It is useful to have both fine chisels and junky chisels for different jobs.
Our evening lecture by Suzana Radivojevic was "The Effects of Climate Change on the Long-term Deterioration Trends of Wood in Cultural Heritage." Climate change increases foraging rates for termites and eliminates long cold periods which would otherwise control insect populations. Greater moisture and temperatures support fungal growth which is optimal between 76-86°F at >20% humidity. Most of the world is at higher risk for wood decay except Southern Europe which is becoming drier.
Thursday, August 25th: Founder’s Day, the 100th anniversary of the National Park Service!
Back at the Field School, wood science class continued. We collected wood samples from the CCC cabins and learned how to section the samples for microscope slides. Crosscut, radial and tangential views of wood cells each provide insight into wood type. Crosscut shows growth rings and resin canals (if present). Radial cuts show tracheids running longitudinally with the trunk. Spiral thickenings in tracheids are common in certain species like Douglas-fir and can be seen in radial cuts. Tangential cuts show the horizontal resin ducts. Cross-field pitting is the connection between tracheids and rays, horizontal runs which carry water and nutrients from the core to the bark. Pitting has very specific structural characteristics and help identify one species from another.
My sample from the old peak lookout of L125 showed no resin canals, so we could eliminate pine, spruce, larch, and Douglas-fir. Odor is an important characteristic of many woods. Mine smells like cedar. Cross-field pitting confirms that this sample is Western Red Cedar.
Switching groups, the afternoon was spent with Amy McAuley learning the basics about frame and sash repair. Our first assignment was to complete the puzzle of assembling a window frame from its component pieces and an architectural drawing of the sill and jamb. We reviewed the names and functions of components of the sash (rails, meeting rails, stiles, muntins, glazing) and the frame (sill, stop, blind stop, mullion, apron, casing, parting bead, weight pocket) and the tools for making mortise and tenon connections, glazing rabbets, bevels, and profiles.
Our evening lecture was about paint color analysis by architect Carin Carlson. She talked about the components of a field kit to collect samples and the process of sampling materials, the tools of a conservation lab, and how to report findings. Substrate can be an important to the historical investigation because it shows layers of finish. Good lighting is critical in the lab and at the microscope. Munsell Book of Color is used as a standard for color identification.
Friday, August 26th:
We reglazed existing double-hung sashes for Cabin L125 with newly cut pieces of 3/32” float glass. A cork-backed metal straight edge provides the fence for a glass cutting wheel which scores the cut. The score must be made in one continuous motion and enough pressure used to hear a tearing sound. Then the pane is flipped over and tapped along the score to create the break.
The pane is fitted into the glazing rabbet of the sash. A small gun is used to fire glazing points into the stiles and bottom rail. The top rail has a glazing pocket cut into it. Then we glaze the pane into the sash with DAP 33 glazing putty.
It is important to work the putty and warm it in your hand prior to applying. After applying the initial bead by hand, a wide scraper is used to compress the putty into the joint. Then a thinner putty knife is glided on its side down the length of the joint to remove excess putty and create a smooth bevel even with the interior edge of the rabbet. Small amounts of whiting powder and a brush are used to remove grease from the window and small amounts of remaining loose putty. The putty will never dry out in its useful life but it will develop a skin after about a week. It should not be painted until it develops this skin.
To reinstall the sashes, we reattached the parting beads using stainless steel nails to prevent rust. Parting beads on this frame are applied to the jamb; there is no dado in which to recess them. We predrilled nail holes to prevent the wood from splitting. Care must be taken to set the parting rail so that the sash is held firmly but can glide freely without binding.
In the afternoon, we completed the repair to the rotted column. A 12” lap joint between new and old provides a large adhesive surface and a path for both compressive and lateral forces to transfer. Both sides of the joint were treated with epoxy and the pieces were held tight with deep screws. These will be countersunk and covered. Once set, the surface of the new wood was dressed to be flush with the old surfaces.
The column, as well as the new lookouts, were treated with a borate preservative to deter fungal growth and insect infestation. Borate powder is mixed with water to make a thin solution. This is applied to all exposed surfaces by brush and allowed to soak into the wood. A second application will be done between 6 and 24 hours later.