Bandelier Historic Structure Report: CCC Buildings

THE BUILDINGS

Stabilization and preservation (as defined in NPS-28) are the primary aims of the rehabilitation work that has been undertaken to date and the further work that has been recommended. Arresting material deterioration and maintaining the structures' ability to withstand weather are the project goals. Some features of the type of construction used at Bandelier have inherent defects. Although exposed, projecting wood members are stylistically correct, have a long traditional base, and are primary character-defining features, they also invite decay and require continual maintenance. Within this context at Bandelier, exposed vigas and canales can be assessed more as character-defining features than as historic fabric. Because of the inherent characteristics of wood in a natural, exposed environment, these members have required replacement approximately every 30 to 40 years. Proper maintenance can help extend this life span. Using project completion reports, as-built drawings, and project histories will greatly assist this effort.

Although no recommendations are made to restore the buildings, it is recommended that — through cyclic maintenance and future rehabilitation — elements of the buildings' past character be reintroduced. Doing so consists of the previously mentioned vegetation control, reintroducing the varied door and window color scheme, and maintaining a more weathered stucco appearance. Future interior rehabilitation for adaptive use should seek to retain the buildings' essential historic character and ambience.

The goal of preservation projects should be to use maintenance to retain original fabric and halt deterioration, to use original materials and methods whenever possible, and to restore missing or deteriorated features where needed to understand the structure or ensure its function. These actions should be undertaken with respect for the original fabric, the district, the individual structure's character and significant characteristics, and recognition of maintenance concerns. Work performed and recommended under Package 224 will maintain the existing district and individual structures' character.

Roofs

For the time being, the roofs are in sound condition but require periodic repair to correct ongoing, and undoubtedly future, leaks. With an equitable balance between proper maintenance and benign neglect, they can be expected to last for some time. Proper maintenance is defined as keeping all canales, scuppers, gutters, and drainage outlets clear of obstructive debris and excessive ice buildup. It also means keeping the roofs clear of excessive overhanging vegetation to limit the number of limbs falling onto the roofs. Cyclic and proper tree pruning are significant components of the roofs' longevity. Much of this cyclic maintenance can be done from ladders to avoid excessive use of the roof surface itself. Benign neglect is defined as staying off the roofs as much as possible except for cyclic inspection and required maintenance. Laying tools and equipment on roofs should be avoided as much as possible. Any temporary repairs should be undertaken through manufacturer warranty or with manufacturer approved materials and methods.

Addressing the aesthetic incompatibility and leakage history of the roof membranes (and its eventual need for replacement) was a major design consideration during the design of the package-related canale work. The majority of the canale replacement project was oriented toward the April 16, 1985, consensus acceptance of a proposal to pursue roof replacement through a cyclic program. The flashing technique employed will allow for new roofing material to form an effective seal at canales without disturbing the metal flashing.

As roof-attached utilities lines are replaced, it is recommended that no effort be made to remove embedded conduit, thereby avoiding the need for additional foam and membrane patching. Any new utility routing should avoid mechanical connections to the roof membrane or wood members.

Over time, as roofs need replacement, it is recommended that single-ply membranes or more traditional roofing systems be pursued. Various ballasting systems should be explored with particular emphasis on loading constraints, flashing requirements, and visual impacts. Recent developments in modified bituminous materials have significantly improved the life cycle performance of built-up systems. One guide to use in the assessment of alternative roofing systems is the degree to which the materials are shop manufactured versus dependent solely on successful quality control in the field. During any replacement work, it is recommended that all the existing roofing system be removed to allow sheathing inspection. In the new work, rigid closed-cell foam insulation board should be installed rather than spray forms containing fluorocarbons. It is also recommended that, during future roof replacement, the top parapet course be removed to allow for the installation of copper through-wall counterflashing and then reset to its original configuration. New coping material should slope to the roof rather than to the wall face.

It is recommended that a small interior access scuttle be provided in each building for periodic inspection and verification of roof framing. Scuffles can be located in closets or other unobtrusive areas to mitigate their visual impact.

Because of their location and the required roof repair, no recommendation is made to reconstruct the missing parapets on B-1 and B-25.

Estimated cost to replace all urethane roofs, including new insulation and metal counterflashing, is $300,000.

Vigas, Canales, Columns, and Lintels

Work undertaken to date has put the majority of the buildings' wood members (with the exception of B-25) in sound condition and within park capabilities of cyclic maintenance. B-25 requires a similar inventory and treatment. Again, with proper maintenance, these members will remain sound for years to come. This proper maintenance consists of keeping canales and their masonry openings free of vegetation and ice buildup; keeping exposed wood (particularly column bases) free of snow and organic debris; maintaining the protective stain coating; and maintaining the integrity of the seal at adjoining masonry surfaces. Those members not replaced or treated should be inspected periodically. Where replacement is required, methods similar to those undertaken to date should be pursued.

Because of their location on rear unseen facades and to lessen future maintenance expenditure, no recommendation is made to reintroduce exposed viga ends on B-1, B-6, and B-25. It is recommended that the visitor center sign be removed from the facade and a smaller sign installed on the lawn. Then the missing viga stubs could be reinstalled over the entry portal.

Walls

A program of continued repointing is required to ensure the proper role of the masonry mortar joints. This work should also include maintaining the integrity of parging at window and door jambs and at the parapet copings.

Because the buildings were constructed over a number of years and each has its own unique, although similar, design, repointing efforts should respect those subtle variations. The results of analysis work undertaken and to be included in the historical structures preservation guide will assist in setting acceptable parameters on the range of pointing mix and texture. Similarly, any stucco work should be guided by historic precedents. Stucco on the buildings is primarily an aesthetic concern, and it provides only minimal protection to the stonework. Wholesale restuccoing has no historic precedent, noticeably changes the buildings' appearance, and is not recommended. Any effective results toward sealing the stonework below would prove visually incompatible.

A great deal of discussion has centered on the "functional" role of the original stucco. It may have helped to seal the mortar joints, but its success is questionable. Because of the stucco's formula, the material undoubtedly allowed air and moisture to move in and out. Even if it were acting as a seal and given the lack of a full stucco coating to the exteriors, any moisture migration through the porous stonework would merely wick around any seal or barrier and continue. Similar action would have occurred for any thermal performance. The whole relationship between mortar and stucco and their original and future replacement compositions is a complex issue that requires careful thought before any parkwide application is made.

Windows and Doors

Like most other building components in the CCC complex, the windows and doors require a system of ongoing cyclic maintenance. Although there are many of them, following a system of inspection, maintenance, and record keeping will greatly assist this effort and lessen the perception that it is overwhelming.

It is recommended that, through cyclic maintenance, missing screens be replaced, wood members that have deteriorated be repaired or replaced in kind, and nonhistoric hardware be replaced with more compatible hardware. If undertaken through contract, this work is estimated at $15,000 to $20,000. Maintaining sound caulking and putty will always be a maintenance concern. To reintroduce much of the complex's former character, it is recommended that the return to a more varied exterior color scheme be considered. This change can easily be reintroduced gradually, in the normal painting cycle.

No effort is recommended to reproduce the original multipane sash in the residential area. However, it is strongly emphasized that no further efforts of wholesale removal of historic fabric should be undertaken without project compliance with section 106 of the National Historic Preservation Act.

On the insulating windows installed to date under this package, a survey should be taken to determine on which windows condensate forms, when, and to what degree.

Alternative treatments should be explored, including drilling air weep holes (from one or both sides) and installing a different seal material to ascertain corrective measures. Until the internal combustion air problem is resolved, no further weather stripping is recommended. In view of the current use of the buildings, insulating windows may not be required on B-1, B-26, and B-30 (no winter use) and B-4, B-5, B-6, B-14, B-21, B-22, and B-25 (unheated, maintenance-oriented structures).

Floors

The continued upkeep of flagstone floors is a strongly expressed maintenance concern. The preferred recommendation is to restore or retain the original oil-and-varnish treatment. A valid alternative is the use of colored waxes, which is a reversible treatment that can be installed adjacent to the former treatment; the comparative wear and maintenance requirements can be evaluated.

In any future replacement of tile flooring, similar material, color, and size should be used. Acceptable replacements are readily available. Wood floors should be power sanded only when absolutely necessary. The application of carpet over concrete floors, where required, should be done with the use of carpet-to-pad adhesives or reversible adhesives only.

Utilities

The only utility-related recommendation concerns resolution of the cabins' combustion air problem. First and foremost, a survey should be conducted on all buildings with all gas appliances (range, water heater, and furnace) in operation. Windows and doors should be temporarily sealed to simulate the presence of weather stripping. Readings of the carbon monoxide level will indicate the level of treatment needed. On buildings with low readings, the solution may be merely to substitute an electric appliance. High readings may indicate the need to acquire all-electric appliances. This substitution of electric for gas appliances is preferred over alternative fabric modification treatments, which would consist of providing direct exterior double-wall vents for the furnaces or water heaters or both.

Asbestos

Following the findings of Los Alamos Laboratory's survey, appropriate action can be developed. Pending these findings and any remedial treatment, caution should be used around the material to avoid any further disturbance. The material may be intact and pose no health hazard. At the least, the material should be visibly labeled and a cyclic inspection program implemented.