The work of temporarily closing a building or other structure includes four major tasks:

1. Documentation—Determining and recording current conditions
2. Stabilization—Performing work to prevent deterioration while the building is not being used
3. Mothballing—Shutting systems down and securing the building for storage
4. Monitoring—Making sure that stabilization and mothballing protect the building while it is not being used

Taken together, these steps represent the best way to prevent the deterioration that can occur quickly when buildings are empty.

Mothballing structures that have fallen into a state of disrepair (for instance, some historic facilities) can be very expensive. In contrast, temporarily closing a newer, wellmaintained building can be much less expensive.

Determining how long the structure will be unoccupied is important. Then you can determine the type of work to be done and the level of maintenance you can expect. If the closure is only going to be for a year or two, some buildings can simply be closed up, the doors and windows secured, and the heating set to just above freezing. Forest Service maintenance and facility managers have closed many buildings and rental facilities seasonally, so they have lots of experience with this type of facility closure.

If the facility is to be mothballed for more than 2 years, more costly measures must be taken. However, the cost of stabilizing current structures, implementing procedures to protect the building, and periodically monitoring the building's condition, can be money well spent when the building is brought back into service.

Documentation

The first step in the process of mothballing is to get a clear sense of the facility's current condition. Knowing the condition will help you set the priorities for the work that needs to be done. The structure's most current facility condition assessment survey provides a starting point for documentation. An extensive condition assessment survey should provide a clear view of the building's needs.

For buildings 50 years old or older, the starting point should be any documentation required for the Forest Service's Heritage Program. Mothballing historic structures eligible for the National Register of Historic Places will require additional documentation. The Missoula Technology and Development Center (MTDC) "Facility Toolbox" http://www.fs.fed.us/eng/toolbox/ (figure 3) has information on the special requirements for historically significant facilities. Also, NPS Preservation Brief No. 31 (Park 1993) details special considerations for documentation and minimal stabilization work for historic buildings.

Figure 3—The "Facility Toolbox" Web site http://www.fs.fed.us/eng/toolbox/
has information on historically significant facilities.

For any mothballing project, the initial documentation should provide information on the age and condition of the basic features of the building, including:

• Foundation
• Structural systems
• Exterior materials
• Roof and gutters
• Exterior porches and steps
• Interior finishes
• Staircases
• Plumbing
• Electrical systems
• Mechanical systems
• Special features such as chimneys
• Site drainage

The building's condition assessment survey may not have enough detailed information for this documentation, but if a survey has been conducted recently, it will have all, or most, of the information you need. If there is no current facilities condition assessment survey, refer to the MTDC report "So That's Why It's Always Cold in Here: A Guide for Conducting Facilities Condition Assessment Surveys" (Peacock and Snodgrass 2004).

Once you have a clear sense of the conditions of the facility's major features, priorities can be set for the work that needs to be done. For example, if the foundation and the roof are sound, you will have many years of service from the building. If there are major problems in either of these areas, you should probably attend to them first.

The initial documentation can also help confirm whether the facility is worth mothballing or whether the building should be demolished or sold. If, for example, the facility is less than 50 years old and in a state of disrepair or if the construction quality was poor, it may be more cost effective to sell or demolish the facility than to mothball it for future use. In such cases, mothballing may not keep management options open but may simply tie a manager's hands. Future costs may include not just mothballing, but also rehabilitation, maintenance, and updating to meet new building standards.

If, on the other hand, the facility condition assessment survey and current documentation support mothballing, the documentation process will help to identify any initial stabilization the structure needs.

Stabilization

Stabilization of certain features may be needed before mothballing to slow deterioration of the building. "If either the roof or the foundation is in poor condition, you will need to stabilize it in some fashion before you can mothball the building" (Matthew 2009). Stabilization of the roof should take into account its structural ability to sustain snow loads in northern climates (figure 4). Structural stabilization should focus on bracing at the ridge and midpoints, particularly if the roof is sagging.

Figure 4—The Moose Creek Cookhouse on the Moose Creek Ranger District,
Nez Perce National Forest, ID, relieved of a heavy snow load.

Ensuring that the building has an adequate roof with sufficient drainage is often mentioned as the single most important step to preventing deterioration in mothballed buildings. "A secure roof is the most important protection the building needs. Water should run off the roof and away from the building. Damaged or insufficient gutters can cause severe problems for wood corners and fascia boards" (Frazier Associates 2002). Repairing leaks, especially from faulty flashing, is an important part of mothballing. Also, roofs and gutters need to be maintained while the building is mothballed.

With historic facilities, there will be resistance to putting on a metal roof. A case can be made however for installing a metal roof, even on historic structures (Matthew 2009). A metal roof may be justified as one way to comply with the requirement that historic buildings are not allowed to deteriorate. A metal roof can be a temporary installation while the building is mothballed and be replaced with a historic roof during restoration. A metal roof could even be put over an existing roof if the structure will support the weight.

Foundations that are weakened by poor drainage, poor design, neglect, or age will need underpinning or bracing. Regional differences in climate, moisture, and construction designs influence the types of stabilization efforts, particularly for foundations, roofs, decks, patios, and other exterior portions of the structure. "If the building is in a southern or humid climate and termites or other insects are a particular problem, the foundation and floor framing should be inspected to ensure that there are no major structural weaknesses" (Park 1993).

If there are known structural problems with the facility, they must be attended to first. A structural engineer or specialist should direct the stabilization efforts to make sure that the existing structure can accommodate any reinforcements, additions, or bracing.

Controlling Infestations

The types and number of pests are influenced by a host of factors related to the building condition, the climate, and the region of the country where the facility is located (figure 5). The full range of pests and instructions on excluding them is beyond the scope of this report. Some of the possible pests include "squirrels, raccoons, bats, mice, rats, snakes, termites, moths, beetles, ants, bees, wasps, pigeons, and other birds" (Park 1993). These invaders can damage the building's structure or, in the case of mouse, pigeon, and bat droppings, pose a health hazard. "If the property is infested with animals or insects, it is important to get them out and to seal off their access to the building" (Park 1993).

Excluding rodents receives a great deal of attention because of the threats they pose to both the condition of buildings and to human health. MTDC has compiled information from Forest Service and the Bureau of Land Management (BLM) field personnel on techniques they have found helpful in "Controlling Rodents in Forest Service Facilities: Reports from the Field" (Snodgrass 2004). Also, the "National Park Service Rodent-Exclusion Manual" (Hoddenbach and others 2005) offers a comprehensive approach to building inspections, preventing and controlling rodent infestations, and sanitation treatments, as well as monitoring and evaluation after treatment.

Figure 5—Insect infestations that have not been controlled before
mothballing can quickly become apparent on windowsills and floors.

Even if animals or insects are kept out of a building, they can still cause extensive damage to the exterior. Birds and animals peck and chew surfaces on buildings, causing damage and sometimes creating new entry points for other animals and insects (figure 6), particularly if buildings are unoccupied.

Several approaches can be used to discourage this type of damage. MTDC has identified a habanero pepper coating that can protect Forest Service buildings, signs, wiring and fencing from damage by porcupines, horses, rodents, and possibly woodpeckers (Snodgrass 2005).

Figure 6—Birds or other animals can peck or chew the exterior of buildings,
damaging a building that has been mothballed.

Preventing woodpeckers from damaging buildings is an issue whether the building is in the city or in a rural area. Another report by MTDC identified some long- and short-term methods to discourage woodpecker damage. These methods include providing nest boxes, developing alternative nest sites, net coverings, and harassment (Jasumback and others 2000).

The U.S. General Services Administration (1998) has prepared an evaluation of the pros and cons of a range of bird control methods http://w3.gsa.gov/web/p/HPTP.NSF/gsagovAllProceduresDisplay/1029601S. This document evaluates bird deterrent systems, including lethal and nonlethal systems.

Controlling Moisture

Preventing moisture from penetrating the exterior of buildings is essential when buildings are stabilized for mothballing. "Leaks from deteriorated or damaged roofing, from around windows and doors, or through deteriorated materials, as well as ground moisture from improper site run-off or rising damp at foundations, can cause long-term damage to interior finishes and structural systems" (Park 1993). While buildings need some moisture for human comfort and for the building's longevity, the challenge is to prevent unwanted moisture from damaging the building.

The NPS Preservation Brief No. 39 "Holding the Line: Controlling Unwanted Moisture in Historic Buildings" (Park 1996) is a detailed resource for identifying and responding to moisture problems. The brief explains: "There is never a single answer to a moisture problem. Diagnosis and treatment will always differ depending on where the building is located, climatic and soil conditions, ground water effects, and local traditions in building construction."

When stabilizing a building for mothballing, identifying signs of moisture is the first step in devising management options.

Although stabilizing a building with moisture problems can seem daunting, most issues can be dealt with through basic repairs, roofing, grade changes, or ventilation treatments.

For high-value historic structures that use older construction techniques, "It is usually advantageous to eliminate one potential source of moisture at a time. Simultaneous treatments may set up a new dynamic in the building with its own set of moisture problems" (Park 1996). Newer buildings have different construction techniques that are better suited to working on several moisture issues at a time.

Successfully dealing with moisture problems requires ongoing maintenance and monitoring. Those charged with monitoring the site, whether they are employees or contractors, need to be familiar with the site, the building, its mechanical systems, and previous moisture treatments.