American Conservation Consortium

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Moisture intrusion through foundation.

Moisture Management Services

Holistic Moisture Control Solutions for Collections, Museums and Historic Buildings

Mildew growth on floor joist.

Most discussion about environmental control centers around systems - heating, air conditioning, dehumidifying, and humidifying.  Providing environmental conditions that are good for collections and people often creates problems for preservation of the building itself.  This can be unacceptable if an historic structure is involved, leading to inadequate preservation of either the collections or the building or both.

Focusing on the source of the moisture and preventing it from entering the building is often more effective, less expensive and reduces the need for mechanical systems and precious energy resources, annually saving money in utility and maintenance costs.  This approach also can allow for good preservation of both the building and the collections at the same time.  The vast majority of moisture that causes unsatisfactory interior RH levels comes from outdoors, either as rain or as high humidity that infiltrate the building.  This does not have to happen!  With a careful holistic plan, much of this infiltration can be prevented, leading to more favorable and stable interior environmental conditions.

American Conservation Consortium provides the following moisture management services.

bulletPreparation of Moisture Management and Control Plans.  This comprehensive document looks at all of the factors influencing the relative humidity of the interior environment.
bulletDesign and management of efficient, inexpensive environmental monitoring programs.  Monitoring provides a baseline of existing conditions and allows determination of the effectiveness of improvement efforts.
bulletEvaluation and design of moisture infiltration improvement options, including site topography and grading, drainage systems, and building envelope tightening.  Some of these activities also can provide dual preservation benefits in other areas, such as light control.  This is an advantage of working with a conservator who understands all aspects of preservation, rather than an HVAC engineer.
bulletDesign of simple, inexpensive environmental control systems for heating, dehumidification and ventilation.  Effective does not have to mean sophisticated and expensive.
bulletDesign and production of inexpensive low-tech environmental controls.

Each site has its own unique needs.  Many projects can be accomplished with in-house staff.  However, when necessary, a team of consultants can be assembled, including preservation architects, architectural historians, HVAC engineers, and product specialists.

Moisture Management and Control Plan

A moisture management and control plan is a fluid document that reflects the then-current conditions, needs and proposed solutions. Once created, it must be updated as needed to accurately reflect changes.  The plan is unique for each site, but commonly includes many or all of the following.

a) Read and evaluate all previous written reports and evaluations concerning moisture issues. Determine what is relevant and accurate, and what suggested improvements or repairs have been implemented. As required, talk with the authors of the reports. Identify recurrent moisture problem areas.

b) Visit the site and perform visual water and moisture infiltration inspections overall, as well as in identified problem areas. Formulate potential solutions, including any necessary testing or applied evaluation.

c) Evaluate the existing guttering system and determine which improvements are required. If necessary, redesign the guttering system.

d) Evaluate overall site drainage and provide suggestions to be incorporated into site grading improvements, if needed. Determine if auxiliary drainage systems are required. Monitoring of the effectiveness of other improvements may have to occur first.

e) Evaluate the moisture management needs of foundations and basement floors. Consider the merits and drawbacks of plastic sheeting and concrete on the basement floors.

f) Evaluate moisture issues with chimneys, both at the fireplace flues and the chimney tops.

g) Evaluate data-logged environmental monitoring data, both before and after improvements.

h) Determine if the existing system of furnaces, dehumidifiers, ductwork and air conditioners, if any, can be adapted with low-tech controls to perform adequately, or if a holistically-designed simple new system is required.

i) Evaluate potential improvements in environmental stability, including the advantages and disadvantages of storm windows and insulation, and the isolation and ventilation of attic spaces. Provide improvement suggestions.

j) Prepare a moisture control inspection and maintenance plan that addresses all of the issues affecting water and moisture intrusion and control. Include specific activities and frequency schedules.

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American Conservation Consortium. Ltd.

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