Preservation Experts on Campus Closure Plan
From Caitlin Meives, the Director of Preservation of the Preservation League of New York State, upon reading the description from the Wells College Board of Trustees about Christie’s overseeing the closure and “moth-balling” of the campus buildings all winter without heat:
“The idea of Christie's advising them on building preservation is very concerning. I could be wrong but I have never known them to work in the realm of building preservation nor does anything on their website suggest they have such expertise….
The claim that the buildings are less likely to be exposed to moisture and mold without heat is misguided at best. Yes, heat generates humidity and yes, without air circulation and doors opening/closing, things would be more stagnant. But without heat the buildings will also experience extreme temperature and humidity fluctuations, which will lead to mold and rot. The buildings should also be regularly monitored to check for mold, roof leaks, etc.
As far as we’re concerned, only a preservation architect would be qualified to evaluate and develop a plan for building maintenance.”
Ms. Meives also shared highlights from the following publications from the National Park Service. (NPS publishes Preservation Briefs that are highly technical documents prepared by architects with extensive experience w/older buildings. She called them “the gold standard” for treatment of older and historic buildings.)
Preservation Brief 24 - Heating, Ventilating, and Cooling Historic Buildings: Problems and Recommended Approaches
https://www.nps.gov/orgs/1739/upload/preservation-brief-24-heating-cooling.pdf
Excerpt: In general, the greater the differential between the interior and exterior temperature and humidity levels, the greater the potential for damage. As natural vapor pressure moves moisture from a warm area to a colder, dryer area, condensation will occur on or in building materials in the colder area (see figure 4). Too little humidity in winter, for example, can dry and crack historic wooden or painted surfaces. Too much humidity in winter causes moisture to collect on cold surfaces, such as windows, or to migrate into walls. As a result, this condensation deteriorates wooden or metal windows and causes rotting of walls and wooden structural elements, dampening insulation and holding moisture against exterior surfaces. Moisture migration through walls can cause the corrosion of metal anchors, angles, nails or wire lath, can blister and peel exterior paint, or can leave efflorescence and salt deposits on exterior masonry. In cold climates, freeze thaw damage can result from excessive moisture in external walls.
Preservation Brief 31 - Mothballing Historic Buildings
https://www.nps.gov/orgs/1739/upload/preservation-brief-31-mothballing-buildings.pdf
Excerpt: A vacant historic building cannot survive indefinitely in a boarded-up condition, and so even marginal interim uses where there is regular activity and monitoring, such as a caretaker residence or non-flammable storage, are generally preferable to mothballing. In a few limited cases when the vacant building is in good condition and in a location where it can be watched and checked regularly, closing and locking the door, setting heat levels at just above freezing, and securing the windows may provide sufficient protection for a period of a few years. But if long-term mothballing is the only remaining option, it must be done properly (see fig. 1 & 2). This will require stabilization of the exterior, properly designed security protection, generally some form of interior ventilation - either through mechanical or natural air exchange systems - and continued maintenance and surveillance monitoring.
And: Once closed up, a building interior will still be affected by the temperature and humidity of the exterior. Without proper ventilation, moisture from condensation may occur and cause damage by wetting plaster, peeling paint, staining woodwork, warping floors, and in some cases even causing freeze thaw damage to plaster. If moist conditions persist in a property, structural damage can result from rot or returning insects attracted to moist conditions. Poorly mothballed masonry buildings, particularly in damp and humid zones have been so damaged on the interior with just one year of unventilated closure that none of the interior finishes were salvageable when the buildings were rehabilitated. The absolute minimum air exchange for most mothballed buildings consists of one to four air exchanges every hour; one or two air exchanges per hour in winter and often twice that amount in summer. Even this minimal exchange may foster mold and mildew in damp climates, and so monitoring the property during the stabilization period and after the building has been secured will provide useful information on the effectiveness of the ventilation solution.
