Introduction

Most preservationists involved in the documentation ofhistoric structures utilize conditions glossaries in theirwork. The conditions glossary is an important toolused in the conservation process: describing the condi-tion of a material is the first step in the evaluation ofthe condition, which leads to a better understanding ofthe cause of deterioration and ultimately treatment ofthe condition. Sometimes the glossaries preservation-ists use are internalized, drawn from one’s backgroundand experience with a particular system or material butoften based on terms developed from various disci-plines. Sometimes preservationists refer to glossariesthat have been published for building or preservationprofessionals and have become, to some degree, in-dustry standards. Although it is not necessary foreveryone to use the same list of conditions, it is usefulto have a common reference point on the generalmeaning of condition terms. The purpose of this articleis to review several glossaries used by preservationistsin order to better understand the features of glossariesas a tool in the survey process.

A glossary is simply an alphabetical list of termswith definitions, usually specific to a particular field ofstudy or discipline. A conditions glossary, then, is a listof terms used to describe the condition of the object,system, or material. Its purpose is to assist in the ob-jective documentation of conditions. By practice, condi-tions surveys are usually most concerned with identify-ing problems, so most of the terms in the conditionsglossaries typically relate to deterioration, degradation,and distress.

Trade groups, government agencies, and preserva-tion organizations have developed many different glos-saries that are available to preservationists. The pub-lished preservation glossaries should be used as acommon reference point, although it may be useful todevelop specific glossaries for a project, as long asthey are shared amongst and understood by the proj-ect team. From the outset of a preservation project, aconditions glossary is important for sharing informa-tion among the entire project team, from the surveyand design teams who conduct the investigation to the

Practice Points NUMBER 12

Conditions Glossaries as a Tool in the Survey Process: A Review of Several Glossaries

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owner who approves the scope of work based on theinvestigation to the contractors and tradespeople whoperform the work. Photographs and images are an im-portant part of a glossary, since they help the team un-derstand the terms in the glossary.

A key question in the examination of conditions glos-saries is whether we are documenting cause or effect.Some glossaries include implicit, or sometimes ex-plicit, assumptions about condition causes. Other glos-saries include terms that are purely descriptive, in anattempt to make the glossary as objective as possible.When the initial conditions survey is conducted, theglossary terms should be an objective description ofthe conditions themselves, without assumptions aboutcause or treatment. The analysis to determine thecause of the conditions will follow from the descriptionof the effects, or symptoms.

Fig. 1.Sample entry for thecrack system in brickmasonry joints in theVertical Access conditionglossary. All images byVertical Access.

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Another feature of some glossaries is a hierarchicalstructure of terms. For example, a glossary may in-clude a definition for the gross term “soiling,” as wellas for specific types of soiling, such as atmospheric,biological, and cementitious; it may then have defini-tions for different types of biological soiling on anotherlevel of the hierarchy. Glossaries with a hierarchical or-ganization of terms can be more easily scaled for aparticularly investigation and allow for documentationto move from a general assessment to a detailed de-scription, making them more flexible than a simple listof terms.

Trade-Organization Glossaries

The first group of conditions glossaries examined hereincludes those developed by trade organizations. Agood example is the American Concrete Institute’s“Guide for Conducting a Visual Inspection of Concretein Service,” ACI 201.1R. First published in 1968, thecurrent version dates to 2008. As stated in the ab-stract for the guide, “its purpose is to establish a uni-form system for evaluating the condition of concrete.”The entire document is essentially a list of definitionsof various conditions with associated photographs.The guide also has a classification system, dividingnearly 50 different conditions into three categories:cracks, distress, and textural features and phenom-ena. In some cases the cause of the condition is ex-plicit in the definition, such as temperature cracking:“cracking due to tensile failure, caused by temperaturedrop subjected to external restraints or by a tempera-

ture differential in members subjected to internal re-straints.” In other cases, the definition is purely de-scriptive with no implied cause: “hairline cracks:cracks in an exposed-to-view concrete surface havingwidths so small as to be barely perceptible.” Althoughdeveloped for concrete, the simple hierarchical organi-zation of this glossary can be adapted to other ma-terials.

Other examples of glossaries developed by trade or-ganizations include the Brick Industry Association’s“Technical Notes 2: Glossary of Terms Relating toBrick Masonry,” the Marble Institute’s “Glossary ofStone Industry Terms,” the Forest Products Labora-tory’s “Glossary,” the Society for Protective CoatingsVisual Comparison Manual, the Master Painter’sInstitute’s Master Painter’s Glossary, and the StainedGlass Association of America’s “Glossary.”1

Many of these glossaries are not specifically condi-tions glossaries. Rather, they are comprehensive glos-saries that include many trade terms; typically they in-clude only a handful of terms relating to material con-ditions or defects, such as “chip” or “spall” for ma-sonry materials. Although these glossaries are usefulfor general reference, they have limited value as condi-tions glossaries.

Similar to the trade-organization glossaries and de-veloped with the input of trade-organization leadersare ASTM standard terminologies for different materi-als and systems; they include many industry terms, in-cluding some relating to conditions and defects. Someof the standards relevant to the documentation of his-toric buildings include C119-09 Standard TerminologyRelating to Dimension Stone, D9-09a Standard Ter-minology Relating to Wood and Wood-Based Products,D16-10 Standard Terminology for Paint, Related Coat-ings, Materials, and Applications, and D1076-10 Stan-dard Terminology Relating to Roofing and Waterproof-ing. Like most trade-organization glossaries, they oftenhave only a few terms relating to material conditions.

Government Agencies

Another group of conditions glossaries available topreservationists are those published by governmentagencies. In the United States the National ParkService (NPS) is the government agency tasked withconserving historic sites and developing preservationstandards and guidelines. One of the first NPS condi-tions glossaries was Anne Grimmer’s A Glossary ofHistoric Masonry Deterioration Problems and Preserva-tion Treatments. This glossary, published in 1984, wasthe result of an NPS initiative to develop a “standardset of definitions for masonry deterioration” for fed-eral, state, and local officials conducting conditionsassessments. It has been widely cited in other refer-ence materials. The 22 deterioration terms are clearlydefined and illustrated with black-and-white photo-graphs. The concise definitions and photographs make

Fig. 2. Sample entry for stone

exfoliation in the VerticalAccess condition

glossary.

PRACTICE POINTS 12 3

this a useful resource. Unlike most glossaries, the de-scription of the conditions also includes discussion ofpotential causes. The second part of the glossary iscomprised of preservation treatments, again illustratedwith photographs.

Other NPS reference publications, especially variousPreservation Briefs, include terminology on deteriora-tion and examples of specific defect conditions for var-ious materials, although these are not intended to beglossaries. Because the Preservation Briefs are in-tended as guides not only for the survey of historicstructures but also their preservation, rehabilitation,and restoration, the discussion of conditions terms isput in the context of their treatment. Typically, only themost common conditions of deterioration for a specificmaterial are included.

Preservation Organizations

Non-governmental preservation organizations have alsodeveloped illustrated glossaries for conservation pro-fessionals. One example is the Illustrated Glossary:Mosaics In Situ Project, developed by the Getty Con-servation Institute (GCI) and the Israeli AntiquitiesAuthority in 2003.2 It contains definitions of “currentconditions” divided into previous interventions, struc-tural conditions, and surface conditions and is illus-trated with photographs and drawings. Similar to AnneGrimmer’s Glossary, this is an example of a focusedreference developed for a specific project purpose andmaterial.

In 2008 the ICOMOS International Scientific Com-mittee for Stone (ISCS) published the Illustrated Glos-sary on Stone Deterioration Patterns,3 which drawsfrom international sources of previously published andunpublished glossaries, including the National ParkService’s Glossary of Historic Masonry. One of thestrengths of the ISCS glossary is its hierarchical organ-ization. Each of the six “families,” or categories —general terms, crack and deformation, detachment,features induced by material loss, discoloration anddeposit, and biological colonization — contains be-tween two and eleven terms, with some terms havingsub-terms. The hierarchy of terms facilitates identifica-tion of a condition within the glossary. The glossary isalso useful as a cross-reference resource, citing bothequivalent terms found in other glossaries and similarbut inequivalent terms for each condition. Another im-portant feature of the glossary is the use of multiplephotographs to illustrate each condition, which cansometimes be as helpful as the written definition inunderstanding the meaning of a condition term. Thephotographs supplement the definitions by providingexamples of different types of stone or stones in differ-ent environments for each condition.

The GCI illustrated glossary for mosaics and theISCS glossary on stone deterioration are both hierar-chical glossaries. The hierarchical structure facilitates

identification of problems on a gross scale by startingwith general classes of conditions. It may be helpful ina conditions survey to first identify the general class ofcondition and then focus on the specific type of fault.The hierarchy allows flexibility in applying the glossaryterms. In some cases it may be appropriate to use themore general terms in the evaluation rather than moredetailed descriptions of the deterioration. For instance,if the intent of a survey is to provide a first-pass as-sessment without necessarily developing treatments, itmay be sufficient to document areas of loss due toerosion and mechanical damage without differentiatingbetween rounding or roughening erosion or cut or abra-sion mechanical damage.4

Vertical Access Conditions Glossary

The unpublished conditions glossary used by VerticalAccess is an example of a material-based glossarywith a hierarchical structure that has been developedfrom other glossaries. It uses libraries of conditions formaterials such as architectural metal, brick, concrete,stone, and wood. Within each material library there areclasses of conditions, such as corrosion for metals,cracks for masonry materials, and infestation anddamage for wood. Each condition may have up to fiveor six types. For example, “surface,” “pitted,” and “per-forated” are used to describe corrosion of metal. Manyof the definitions are drawn from published sources,such as ACI’s “Guide for Conducting a Visual Inspec-tion of Concrete in Service“ and Grimmer’s Glossary.As a reference, there are illustrated entries for eachcondition (Figs. 1 and 2).

Using the condition of “spall” as an example, it isclear that there are many different working definitionsfor this term. The working definition of “spall” for ma-sonry materials that Vertical Access uses is “a pieceof material dislodged from a masonry unit by exces-

Fig. 3. Bonded spall inlimestone.

Fig. 4. Incipient spall inlimestone.

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sive, localized stress; may result from an impact or alocalized accumulation of stress within the masonry.”Within each library of conditions for masonry materi-als, spalls are further characterized as bonded, incipi-ent, missing, missing with metal, removed, or removedwith metal.• Bonded. Piece of material dislodged from masonry

that appears, based on visual inspection and onsounding with a mallet where possible, to still be at-tached to substrate, typically by means of mortar oradhesive (Fig. 3).

• Incipient. Partially formed spall that appears to bewell attached (Fig. 4).

• Missing. The location of a spall that is no longer insitu at the time of investigation; no steel or othermetal evident (Fig. 5).

• Missing with metal. Location of spall with steel, iron,or other metal evident within depression left bymissing spall.

• Removed. Location of spall taken from the buildingat the time of investigation (Fig. 6).

• Removed with metal. Location of spall taken fromthe building at the time of investigation; steel, iron,or other metal evident within depression left by re-moved spall.

These terms provide a snapshot of the existing condi-tions of the material at the time of survey. They are rel-atively objective, focusing more on effect than cause.The terms are hierarchical, starting with the generalterm “spall,” which is then divided into specific typesof spalls. Depending on the purpose of the survey, itmay be sufficient to document the general class ofcondition without identifying specific types.

For comparison, listed below are definitions of“spall” or “spalling” from some other glossaries:• Marble Institute: “a chip or splinter separated from

the main mass of a stone.” This is very simple, de-

scriptive definition, but the choice of words (chipand splinter) implies a small area relative to the unitand leaves open the question of what to call largerareas of loss (Fig. 7).

• ASTM Standard Terminology Relating to DimensionStone: “fragments or chips from a piece of dimen-sion stone.”

• Brick Industry Association: “a small fragment re-moved from the face of a masonry unit by a blow orby action of the elements.” This definition includesan explicit description of cause.

• American Concrete Institute: “a fragment, usually inthe shape of a flake, detached from a concretemember by a blow, by the action of weather, by pres-sure, by fire, or by expansion within the largermass.” Spalls are further divided into joint spalls(spalls adjacent to joints), small spalls (less than0.8 inches in depth and 6 inches in any dimension),and large spalls (greater than 0.8 inches in depthand 6 inches in the greatest dimension).

• Preservation Brief No. 7: “the partial loss of the ma-sonry material itself, is, like crazing, caused by waterand is usually a result not only of airborne water butmore commonly of water trapped within the masonrysystem itself.” It focuses even more on the cause ofthe condition.

• ICOMOS International Scientific Committee for Stoneglossary: Spalling is a type of contour scaling foundin flat dimension stone “in which the interface withthe sound part of the stone is parallel to the stonesurface.” Loss of stone sections having greaterdepth would be called “bursting” or “chipping” (Fig.8). It also focuses on the process of deterioration.

These examples illustrate the variation in definitionsfor one type of condition. Some descriptions of spallsprovide information, whether stated or implied, on sizeor extent. Other definitions are more general. Withoutan agreed-upon definition, two people looking at thesame condition might use different terms to describethe same fault. Even using predefined terms in thesurvey, it is important that the entire project team un-derstands the definitions of the terms. Photographscan be helpful to visualize and better understand thedefinitions.

Another difference between definitions in the exam-ple of “spall” and “spalling” is the intent of the glos-sary. In some cases, the definition of a term is derivedfrom the process of deterioration, such as the descrip-tions of spalling found in the NPS Preservation Briefand the ICOMOS ISCS glossary. Other terms, espe-cially those from trade-organization glossaries, aremore objective descriptions of the observable condi-tions without assumptions about the cause orprocess.

Although it is necessary to understand the causesof deterioration, it is important not to prematurely as-sign causes to observed conditions. The conditionssurvey is the first step in the evaluation of the material

Fig. 5. Missing spall in

limestone.

Fig. 6. Removed spall in granite.

PRACTICE POINTS 12 5

defects and should be as objective as possible. Thecauses of the conditions documented during the sur-vey are typically evaluated as part of the next step inthe conservation process, the conditions assessment.

Conclusion

A conditions glossary is a tool used during the docu-mentation phase of a project, which is the first step ina multiphase process. The terms used in the glossaryand survey should be objective descriptions of the con-ditions. The documentation phase might also includereview of archival material on as-built construction andalterations, maintenance records, and previous repaircampaigns; analysis of fault patterns using the com-plete set of survey data; and investigative probes ornondestructive testing. This holistic approach duringthe documentation phase will help to determine thecauses of the deterioration observed in the conditionssurvey so that appropriate treatments can be devel-oped from the conditions assessment.

Conditions glossaries help preservationists under-stand materials by focusing on their observable andcurrent state. The published glossaries described inthis Practice Point are valuable tools for documentingconcrete, stone, and other masonry materials. Theywere developed for a specific purpose, however, and so they may not completely serve the needs of everyproject.

There are likely many glossaries developed for spe-cific projects or by preservationists for their in-houseuse. Sometimes the glossaries are used in the field asa reference, but more often they are internalized orused as a general guide. It is important to know aboutthese resources to understand the origin of theseterms. Whether using a published glossary or a glos-sary developed for a project, all members of theproject team should understand the terms and theirdefinitions.

Hierarchical glossaries tend to be more dynamicthan simple alphabetized glossaries. They typically pro-vide a greater range of terms for measuring, describ-ing, and documenting existing conditions. Dependingon the scope of the survey and detail required, it ispossible to use more general condition terms or a sub-set of terms rather than the full list of conditions.

It is important to keep in mind the limitations ofconditions glossaries. A working glossary can be devel-oped to cover many defects, although there will alwaysbe outlier conditions that are not included. It is neces-sary to recognize these outliers and document them inan understandable way. Another limitation is that con-ditions glossaries are often material-based. By focus-ing on specific materials, defects related to buildingsystems may be overlooked. It is important to be mind-ful to look at the big picture, in addition to the detaileddescription of individual faults. Although the intent ofmost conditions glossaries is to develop a reference

for the objective documentation of existing conditions,judgment derived from experience is useful in applyingthe information.

EVAN KOPELSON is a partner with Vertical Access, LLC, wherehe has helped to manage the firm’s field projects since 2005.An architectural conservator, his professional practice focuseson conditions surveys and the documentation of materials aspart of building investigations.

Notes

1. For more information, see the Condition Glossary ReferenceList.

2. Getty Conservation Institute and the Israeli Antiquities Authority,Mosaics In Situ Project: Illustrated Glossary (Los Angeles: GettyConservation Institute, 2003).

3. ICOMOS-ISCS, Illustrated Glossary on Stone DeteriorationPatterns (Paris: ICOMOS, 2008).

4. Ibid.

Condition Glossary Reference List

Trade OrganizationsAmerican Concrete Institute Committee 201. ACI 201.1R-08:

“Guide for Conducting a Visual Inspection of Concrete inService.” Farmington Hills, Mich.: American ConcreteInstitute, 2008.

Brick Industry Association, “Technical Notes 2: Glossary of TermsRelating to Brick Masonry,” Jan./Feb. 1975, reissued Mar1999. http://www.gobrick.com/BIA/technotes/t2.htm

Forest Products Laboratory. “Glossary” in Wood Handbook: Woodas an Engineering Material. General Technical Report FPL-GTR-190. Madison, Wisc.: U.S. Dept. of Agriculture, ForestService, Forest Products Laboratory, 2010. http://www.fpl.fs.fed.us/documents/fplgtr/fplgtr190/glossary.pdf

Marble Institute. “Glossary of Stone Industry Terms.” http://www.marble-institute.com/consumerresources/glossary.pdf

Master Painters Institute. The Master Painter’s Glossary.Burnaby, B.C.: Master Painters Institute, 1997, revised 2004.

Fig. 7. Chipping at edge ofmarble unit, which meetsthe Marble Institute’sdefinition of “spall.”

Fig. 8. Spall in sandstone unit,similar to the photographin the ISCS IllustratedGlossary showing“bursting.”

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fax (toll free) 888.723.4242administration@apti.orgwww.apti.org

Society for Protective Coatings. Visual Comparison Manual:Application and Coating Defects. Pittsburgh, Penn.: Societyfor Protective Coatings, 1999.

Stained Glass Association of America. “Glossary” in Conser-vation and Restoration of Stained Glass: An Owner’s Guide.Raleigh, N.C.: Census of Stained Glass Windows, 1988.

American Society for Testing and MaterialsStandard TerminologiesASTM International. C119-09 Standard Terminology Relating to

Dimension Stone. West Conshohocken, Penn.: ASTM Inter-national, 2009.

ASTM International. D9-09a Standard Terminology Relating toWood and Wood-Based Products. West Conshohocken, Penn.:ASTM International, 2009.

ASTM International. D16-10 Standard Terminology for Paint,Related Coatings, Materials, and Applications. West Consho-hocken, Penn.: ASTM International, 2010.

ASTM International. D1076-10 Standard Terminology Relating toRoofing and Waterproofing. West Conshohocken, Penn.:ASTM International, 2010.

Practice Points presents essential information on technicaltopics related to preservation practice for both new and expe-rienced professionals.

© 2011 by the Association for Preservation Technology Inter-national. This Practice Point originally appeared in Vol. XLII,No. 1, of the APT Bulletin, The Journal of Preservation Tech-nology. Reprint requests should be submitted in writing to theAssociation for Preservation Technology International, 3085Stevenson Drive, Suite 200, Springfield, IL 62703, or toinfo@apti.org.