Storage and Care of Architectural Records
This guide is meant to be a general overview of best practices that can be implemented and resources that can be consulted for the preservation of architectural record materials. The intended audiences are institutions that hold architectural records as part of their collections, and private individuals who are caretakers of architectural records and who may be considering their transfer to an archive or repository. For in-depth recommendations on topics and further information, several resources have been created that can be linked to from the menu on the left.
- Temperature and Relative Humidity
- Biological Enemies
- Storage, Use and Handling
- Disaster Prevention, Preparedness, and Response
Definition For the purposes of an architectural archive and these recommendations, architectural records are any document or object where architecture (including: building, engineering, planning) is the subject. Beautiful renderings or perspective drawings are often assumed to be the only valuable part of a collection, but supporting documentary materials such as specifications, site photographs, and contracts are equally important to the history of architecture and historic building preservation. These types of record materials provide valuable information that is lacking in presentation drawings. Presentation drawings, the end result of the design process, are very pretty but they are not as useful as the other types of records because they often do not reflect the “as-built” design. When a building has been altered or destroyed, these other records may be the only witness to the architect's or builder's original design, and the intended relationship to the environment.
Types of Records Architectural records include a great scope of material types, including:
- original drawings (working drawings, colored renderings, structural drawings, sketchbooks, trace papers, linens)
- reproductions (blueprints, sepias, white lines, photographic, hectographic, photomechanical, plotter prints)
- documentation (specifications, planning documents, office records, photographs, films, video, oral histories, computer records)
- three-dimensional objects (architectural models, plaster maquettes, awards, original office furniture, product samples)
Within the material types listed above there coexist an astounding multitude of physical types (paper, plastics, wood, photographic materials, adhesives, traditional art media, magnetic and digital media on tapes, diskettes or other recording medium) all of which are vulnerable to degradation at different rates and by different processes. Light and heat provide energy and humidity provides a pathway for naturally occurring deteriorative processes. Humidity and heat also provide life support for pests and molds. Of course, light, heat and humidity are present in a working environment. The goal for preservation-minded collections managers is to reduce exposure and maintain a stable balance of conditions that are appropriate for the materials. Minimizing environmental impact on your collections by reducing and limiting exposure to light, heat, humidity and handling will reduce deterioration significantly for all material types.
Damage from light is cumulative and nonreversible. The energy in visible and non-visible light is sufficient to drive degradation reactions such as fading of media, or darkening and embrittlement of wood-based papers. Materials should be protected from overexposure due to direct sunlight and from constant interior lighting. If materials are stored in a lit office, viewing room or stack environment, exposure may be controlled by boxing, sleeving or covering materials when not in use. Windows can be covered with blinds or curtains, or window panes with ultra-violet (UV) filtering film (also useful for covering glass-fronted bookcase doors) or double UV filter glazing. Fluorescent lights, which emit higher amounts of UV but less heat than incandescent bulbs, may be shielded with special UV filtering sleeves for the bulbs or with diffusers on the fixtures. Filters and diffusion reduce the amount of UV light, but do not eliminate damage completely. Meters can also be used for testing the efficacy of UV filters over time. Motion-sensing lights or timers can help to reduce light exposure in lesser-used spaces, as well as reduce energy costs. Light levels in exhibition, reading or storage spaces can be monitored with a light meter capable of taking UV and visible light readings. Some types of colored images (blueprints and sepias, drawings made with watercolor, pastel, marker or colored pencil) are extremely susceptible to fading and should be viewed in controlled conditions. In a reading room environment, these materials should be covered with a larger piece of clean acid-free paper whenever they are not in current use.
Acceptable temperatures for storing collections in a working environment range from 65-70° Farenheit with levels of relative humidity in the range of 45-50%. These conditions can be most evenly maintained in inside rooms, away from heat sources such as heating pipes and radiators, windows and exterior walls. Monitoring conditions in your storage areas in a systematic manner over time will give you insight into how well your building adjusts to seasonal climatic conditions and can highlight problem areas. This is best monitored with the use of a recording hygrothermograph. Some options in hygrothermographs include: pen & ink graphing; built-in or portable digital meters that output to computer software; electronic instant readout type available from a household electronics store. Your physical plant manager may also be able to provide you with data regarding your rooms' air handling systems and point out solutions for problem areas.
Drier conditions will reduce the flexibility of materials resulting in: difficulty opening books and and unrolling papers; shrinkage and separation of adhered materials; increased cracking of brittle paper, wood, and paint. More humid conditions will increase the potential for mold outbreaks and increase the rate of acid hydrolysis of paper and plastics. Be aware that photographic materials benefit from cooler, drier conditions than exist in a working environment. If the photographic or other collections are not accessed often, consider creating or sharing in an alternate storage space where the temperatures can be held at lower temperatures and relative humidity and more tightly controlled. Materials which are accessed from cold storage should be allowed to come to equilibrium with the climate of the working environment before they are used.
Organic materials in archival record materials, food and food garbage provide nourishment for the digestive systems of a host of unwanted visitors to your collections. Microscopic molds and insects which feed on glue, paper and cloth are themselves prey for pests such as larger insects, rodents, lizards, birds and all manner of species along the food chain. These pests are not only a danger to the collections, but can present a health hazard for the user and worker as well. Pests and molds seek warmth and water to survive, so the presence of pests and molds are indicative of environmental and maintenance problem(s) affecting your collections, such as unsealed windows or doors, poor sanitation, poor drainage, or poor air circulation. Eliminating standing water sources such as blocked drains, plants, constant or recurring leaks is also key to reducing infestation.
Pests - About Integrated Pest Management (IPM) is a systematic approach to reducing and eliminating pest problems. It involves ongoing identification of species, of pest behavior and actively reduces pest populations through monitoring, improving the cleanliness and conditions of the environment, and staff-wide education. IPM also advocates quarantining and inspecting incoming collections for evidence of infestation before materials are processed into collections. Approaches to pest eradication in objects and buildings include fumigation, non-toxic fumigation (including anoxic or oxygen-displacement treatments), freezing and thermal treatments. If you suspect you have an infestation and need immediate help, see the Additional Resources page to contact preservation support organizations or disaster recovery specialists for further advice. Further reading is suggested in the Bibliography.
Pests - Health & Safety
Pests can present a real health and safety threat to the immediate users of the collections (custodians, handlers, users) and non-users (others present in the building).
Mold - About Mold (including mildew and fungi, there are thousands of distinct varieties) is an perennially present problem in book and paper collections, especially in hot and humid climates. Mold spores are everywhere and are spread by touch, handling, air circulation, or generative growth. Molds are usually dormant, waiting for climatic conditions that are favorable to their feeding and growth. Molds feed on organic material present in paper, adhesives, leather, photographs, etc.
Mold - Health & Safety Molds present a real threat to the health and safety of immediate users of the collections (custodians, handlers, users) and non-users (others present in the building - mold travels and thrives in air-handling systems and walls). Some molds are toxic in small amounts, all molds can be dangerous in excess amounts. Threats to health and safety may differ between persons depending on their medical histories; repeated exposure to molds can result in increased allergic reactivity.
Mold - Preventing Outbreaks High humidity (above 70% for most molds) is extremely favorable to mold regeneration, speedy growth and equally speedy destruction of the material on which the mold feeds. Stagnant air and darkness are also favorable to mold growth, because the two keep the humidity levels constant. Dampness due to seasonal conditions, leaks, and water-damaged materials are excellent breeding grounds for the source of an outbreak. Please see section above on Temperature and Relative Humidity and Bibliography for readings on mold.
Mold - Responding to Outbreaks Use common sense and consider health and safety first! A severe mold outbreak can be extremely hazardous to your health. If the situation does not appear safe, do not attempt to touch, move or clean materials without outside help. Consult immediately with preservation support organizations who offer disaster-related support (see Disaster Prevention, Preparedness, and Response below). They can help you determine the severity of the situation, point you to appropriate resources and some may be able to assist in recovery efforts. Inform your disaster action team, administration and physical plant. If it is a small outbreak or if you are familiar with emergency mold response, do as much as you safely can to: determine the cause of the outbreak; isolate materials or restrict access to the objects or room; take steps to lower the temperature and relative humidity, install and empty dehumidifiers frequently; consult print and web resources, preservation support organizations or your disaster recovery contacts regarding recovery, cleaning, disposal and remediation of the source problem.
Pests and Mold - Quarantine Incoming materials can be a blessing or a boon to your collection, depending on what they bring with them! Your accession protocol should provide a time period for inspection and observation in a "quarantine" room isolated (ideally, physically sealed) from the collection. Quarantine inspection identifies any problematic materials or possible infestation in the objects and packaging materials. The affected materials can then be treated before integrating them into the collection, preventing larger disasters. Please see the Bibliography for further resources.
Storage systems can range from simple in-house boxing to compact storage installations, but they all essentially provide the same function: the isolation of materials from light, dust, harmful adjacent materials, and added protection from physical forces of crushing, bumping and accident.
Storage materials Ideally, non-acid-free storage materials should be replaced wherever possible. When purchasing boxes, paper or folder stock, the term acid-free should not be confused with buffered. Buffered indicates that there is an intentional deposit of alkaline material in the paper stock which can absorb a certain amount of acid from the contents of the folder or the surroundings. This is usually a desirable factor, but contact with alkaline materials may cause color shifts in color photographs, some color media, and in blueprints and cyanotypes (especially if the materials get wet). You will also see the term lignin-free. Lignin is a substance native to trees which contributes to discoloration and brittleness in wood-based paper. It is usually removed during processing of wood pulp destined for “archival” papers.
Boxes and folders are an effective means of creating micro-climates and provide support and organization for loose, rolled materials in storage fixtures or furniture such as stack ranges and flat files. Boxes of acid-free board are available in many standard shapes and sizes for legal files, glass plate negatives, newspapers, film reels, etc. Some vendors will create custom sizes to fit a non-standard size collection of objects with an order of as few as 10 boxes.
If your budget is limited, you may choose to purchase only acid-free and lignin-free paper and folder stocks, instead of both buffered and unbuffered . Another solution is to purchase buffered folders, and interleave color materials with non-buffered papers. Cost-saving options include using non-acid-free materials (such as cardboard roll holders) to temporarily support the materials wrapped in acid-free paper or polyester, but these should not be considered to be safe long-term storage units.
Storage furniture Museum quality metal flat files with baked epoxy finishes are best, and wooden or particle board flat files should be avoided. If the latter are your only options, they should be lined with barrier materials such as archival blotting paper or a metallized polyethylene such as Marvelseal™ to avoid contact with the wood. Normally, per manufacturer's instructions, flat files should not be stacked more than three high. You should always have enough room to open the flat file drawer completely before attempting to take out materials, and have a support board ready to hold the materials you are selecting. Hanging map files are not recommended for use with archival, fragile materials. For examples of storage options see Preservation Administration Work Performed by Kilgarlin Students.
Use and Handling Reduce damage in-house by using proper methods and common sense when handling. Create and use designated carrying boards (oversize sheets of Fome-cor® or acid-free corrugated board) to support flat materials. Have these at the ready when you are taking items out of flat files. Use trucks to transport several rolls, books or boxes at a time and have empty tables at the ends of stacks to hold material. Do not use trucks where oversized materials are sticking out of their storage area.
Reduce damage by users. Most damage to materials happens through use, including careless handling and notetaking. Many institutions create guidelines for users regarding the use of rare and fragile materials. For an example, see our pages How To Research In An Archive and Guidelines for Using Archival Materials.
Self-destructive paper and other materials Some materials such as acidic paper, cellulose nitrate or cellulose acetate plastic films are self-destructive and a danger to other materials. Controlling the environment can slow the deterioration but not completely prevent it. In some cases, the degradation of one type may severely affect neighboring material and should be identified and isolated. Dye components and chemical residues or degredation products in prepared print reproduction or drawing papers (such as sepias) can migrate from sheet to sheet, discoloring and obscuring information. Deteriorating cellulose nitrate motion-picture or print negative film is a definite fire hazard, especially where it is in volume and in an uncontrolled environment; cellulose nitrate film in the form of transparent drawing supports is a lesser hazard. Early formulations of cellulose acetate are subject to deformation, shrinkage, and severe embrittlement. Cellulose nitrate and acetate give off gaseous nitric and acetic acid respectively as they decompose. These acids are irritants in high concentration and contribute to the deterioration of neighboring materials. Isolation by removal, re-foldering or reformatting problematic materials such as these may be the best option to ensure the survival of the information.
Three-dimensional objects (such as architectural models, material samples, and plaster maquettes) are often fragile due to the materials and methods used in their construction, are subject to all the vulnerablities mentioned in the above sections, and may be structurally unsound. They should be stored in a location that protects them from bumping and frequent movement. Sturdy, braced, deep open shelving rated for the weight of the objects is an excellent option. The objects or shelves can be draped in undyed cloth (to prevent light fading) and/or polyethylene sheeting to prevent build-up of dust. Smaller objects can be custom-boxed or put in standard boxes filled with acid-free tissue or polyethylene foam spacers to prevent movement within the box. If you wish to display three-dimensional objects such as models, they should be enclosed in a display case and covered when visitors are not present. If you do not have access to a display case, the object should be covered whenever possible to prevent fading and the accumulation of dirt. Accumulated dirt may be brushed off with a soft brush, but one risks dislodging flaking media or unstable parts of the object. Vacuuming with a standard vacuum cleaner is not recommended. It is best to seek the advice of an objects conservator before attempting to clean an object.
Prevention Some disasters can be avoided by following guidelines for the environment, storage, use and handling for your collections. Keep an eye on the building fabric and its relationship to your storage area. Identify, repair or avoid sites of previous leaks or problems. Monitor your storage locations throughout the year to identify any hazard or patterns (ex. leaves building up in outdoor drain, causing water to back up around a basement window). Proper storage and handling will reduce accident risk. Avoid below-ground or attic storage wherever possible.
Preparedness Have a PLAN. A disaster plan is your best friend in case of emergency, whether that be flood, fire, pest/mold invasion or accident (ex. shelving collapse). A disaster plan has many components, including identifying and creating a team of staff members and contacts responsible for disaster response and salvage, identifing salvage priorities and procedures, insurance, communications, payroll, cataloging, etc.
Learn disaster assessment, communication and salvage skills. Many resources are available to help you learn how to assess and handle emergencies appropriately, showing you how and when to respond yourself or when to call in additional help. Disaster related preservation support organizations, printed manuals, books, and online resources are all listed in the Bibliography and Additional Resources pages.
Response In the event of collections-related disaster, do not attempt to enter the area if there is any danger to your health and safety. Do not enter a flooded room until you know the electrical current has been shut off. Unless you have had disaster recovery training, do not attempt to rescue materials yourself and consult immediately with preservation support organizations offering disaster-related support (see list below). They can help you determine the severity of the situation, point you to appropriate resources and some may be able to assist in recovery efforts. Inform your disaster action team, administration and physical plant.
If it is a small controllable disaster or if you are familiar with emergency response procedures, do as much as you safely can to: determine and mitigate the source of the problem (ex. pipe burst, locate and shut off water valve); isolate materials or restrict access to the objects or room; take steps to lower the temperature and relative humidity, install fans and dehumidifiers, empty dehumidifiers frequently; consult print and web resources, preservation support organizations or your disaster recovery contacts regarding recovery, cleaning, disposal and remediation of the source problem.
Response - Assistance For federal emergency response in a large scale disaster, you can find your state Federal Emergency Management Director at their page, State Offices and Agencies of Emergency Management. For a smaller scale disasters, many library and preservation organizations operate disaster response activities serving discrete regional areas of the US.
|Organization||Support Offered||Phone Number|
|Southeastern Library Network, Inc. (SOLINET)||emergency support, consultation and recovery assistance||800-999-8558|
|AMIGOS Library Services||24-hour emergency support, consultation and recovery assistance||
(after 6 pm CST)
|Northeast Document Conservation Center (NEDCC)||24-hour emergency support, serves callers nationwide||978-470-1010|
|Midwest Art Conservation Center (MACC)||24-hour emergency response and recovery assistance||612-870-3120
(8:30 am-5:30 pm CST)
See the Disaster Preparedness Clearinghouse to find your local library disaster network and for more resources. Please also see our Additional Resources page to locate Preservation Support Organizations and information resources.