ASTM E2260-03

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:E2260–03
Standard Guide for
Repointing (Tuckpointing) Historic Masonry
This standard is issued under the fixed designation E2260; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope C67 Test Methods for Sampling and Testing Brick and
Structural Clay Tile
1.1 This guide applies only to existing historic masonry
C140 Test Methods for Sampling and Testing Concrete
construction. For purposes of this guide historic masonry is
Masonry Units and Related Units
intended to refer to buildings that have significant historic,
C170 Test Method for Compressive Strength of Dimension
architectural, cultural or social meaning and are constructed of
Stone
masonry materials. Similar techniques and evaluation should
C270 Specification for Mortar for Unit Masonry
be employed for non-historic masonry, but are not addressed in
C780 Test Method for Preconstruction and Construction
this guide.
Evaluation of Mortars for Plain and Reinforced Unit
1.2 This guide outlines procedures for repointing historic
Masonry
masonry and is intended to provide guidelines for the user to
C1072 Test Method for Measurement of Masonry Flexural
establish project-specific requirements for repointing of his-
Bond Strength
toric masonry.
C1324 Test Method for Examination andAnalysis of Hard-
1.3 This guide only pertains to masonry units: brick, terra
ened Masonry Mortar
cotta, stone, cast stone, and concrete brick laid in mortar, and
E631 Terminology of Building Constructions
may or may not be appropriate for other masonry units.
E1857 Guide for Selection of Cleaning Techniques for
1.4 This guide addresses repointing (tuckpointing) as de-
Masonry, Concrete, and Stucco Surfaces
fined in 3.1.3.
2.2 Other Referenced Documents:
1.5 When considering repointing, especially on masonry of
ACI 530.1/ASCE 6/TMS 602 Specifications for Masonry
artistic, architectural, cultural, or historical significance, guid-
Structures
ance from a specialist experienced in historic masonry and
London, M., Masonry: How to Care for Old and Historic
repointing should be sought.
Brick and Stone,ThePreservationPress,Washington,DC,
1.6 This guide does not address pointing styles or profiles
used on masonry or the methods of producing them.
“The Secretary of the Interior’s Standards for the Treatment
1.7 Additional repairs that may impact the structural integ-
of Historic Properties,” U.S. Department of the Interior,
rity of the masonry may necessitate that a structural stability
National Park Service, Preservation Assistance Division,
analysis be completed prior to the execution of any work.
Washington, DC, revised 1995
1.8 Following this guide may involve hazardous materials,
McKee, H. J., “Introduction to Early American Masonry:
operations, and equipment. This standard does not purport to
Stone, Brick, Mortar, and Plaster,” The National Trust,
address all of the safety concerns, if any, associated with its
Washington, DC, 1973.
use. It is the responsibility of the user of this standard to
Technical Note 7F, “Moisture Resistance of Brick Masonry
establish appropriate safety and health practices and deter-
Maintenance,” Brick Industry Association (BIA), Reston,
mine the applicability of regulatory requirements prior to use.
VA, Reissued October 1998
2. Referenced Documents
Technical Note 1, “All-Weather Construction,” Brick Indus-
tryAssociation (BIA), Reston, VA, Revised March 1992
2.1 ASTM Standards:
“Preparation and Use of Lime Mortars: An Introduction to
the Principles of Using Lime Mortars,” Historic Scotland,
This guide is under the jurisdiction of ASTM Committee E06 on Performance
Edinburgh, Scotland, 1998
of Buildings and is the direct responsibility of Subcommittee E06.24 on Building
Oats, J. A. H., Lime and Limestone—Chemistry and Tech-
Preservation and Rehabilitation Technology.
nology, Production and Uses, Wiley-VCH, New York,
Current edition approved Feb. 10, 2003. Published March 2003. DOI: 10.1520/
E2260-03.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Mack, R. C., and Spewick, J. P., Preservation Brief #2,
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
“Repointing Mortar Joints in Historic Brick Buildings,”
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. National Park Service, U.S. Department of the Interior,
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
E2260–03
Washington, DC, 1998 4.2.6 Establishing the method of execution of the work.
Weaver, M., Conserving Buildings: A Guide to Techniques
4.2.7 Visual inspection of the work.
and Materials, John Wiley & Sons, Inc., New York, NY,
5. Determination of Joints to be Repointed
IS 240 “Trowel Tips: Tuckpointing,” Portland Cement As-
5.1 In many cases, not all joints in the masonry need to be
sociation, Skokie, IL, 1992
repointed. It may be prudent to repoint only portions of the
3. Terminology masonry or not to repoint at all (see Secretary of the Interior’s
Standards).
3.1 Definitions of Terms Specific to This Standard:
5.2 Closely examine mortar joints to determine which joints
3.1.1 in-situ mortar—mortar existing in the masonry con-
require repointing. Defective joints require repointing. Defec-
structionwhichincludestheoriginalsettingorpointingmortar,
tive joints include joints that are cracked, deteriorated, eroded,
or both and subsequently installed setting or repointing mortar.
contain voids, or are poorly bonded to masonry units. Cleaning
3.1.2 masonry—for this guide, masonry is defined as brick,
of selected areas of the masonry to help identify areas needing
terra cotta, stone, cast stone and concrete brick which is set in
repointing should only be done when necessary for evaluation
mortar.
(see Guide E1857 and Secretary of the Interior’s Standards).
3.1.3 mortar removal techniques:
3.1.3.1 chiseling—use of a hammer and chisel to remove
5.3 If the masonry was previously repointed with a mortar
mortar. which has a higher compressive strength than the adjoining
3.1.3.2 power chiseling—hand-held short stroke pneumatic
masonry, the previously installed repointing mortar should be
carving tool with a round shank chisel blade with no retainer to removed and the joints should be repointed.
remove mortar.
5.4 Visually inappropriate, previously installed repointing
3.1.3.3 power router—hand-held motor driven device using
mortar should be replaced. If color, texture, and joint profiles
a diamond embedded router bit or other suitable abrasive bit to
do not match the existing historic mortar joints, the joints
removal mortar.
should be removed and repointed.
3.1.3.4 raking—use of a hand tool to remove mortar.
5.5 In some cases, sealants or other inappropriate materials
3.1.3.5 sawing/grinding—use of a diamond-tipped, silicon
mayhavebeenusedinjointsofmasonryunits.Thesematerials
carbide-tipped, or other suitable abrasive blade to remove
should be removed and the joints repointed.
mortar.
3.1.4 original mortar—mortarusedintheoriginalconstruc-
6. Evaluation of In-Situ Masonry
tionofthemasonrywallwhichmaybeonlytheoriginalsetting
6.1 If shoring of the masonry is required, the necessary
mortar or may also include original pointing mortar.
materials and methods should be identified.
3.1.5 original pointing mortar—the mortar placed into a
joint (exposed outer edge) from which fresh setting mortar was 6.2 Evaluate In-Situ Mortar:
raked out during original construction of the masonry wall.
6.2.1 In-situ mortar may include previously installed re-
3.1.6 point—placing mortar into a properly prepared joint.
pointing mortar, and each masonry structure may be comprised
3.1.7 repointing—the process of removal of defective mor-
of different mortars of varying ages and materials. Identifica-
tar from between masonry units and placement of fresh mortar.
tion of the original mortar is an integral part of the process of
3.1.8 repointing mortar—the new mortar to be selected by
selecting an appropriate repointing mortar.
the user of this guide.
6.2.2 The color and texture of the in-situ mortar to be
3.1.9 specialist—architect, conservator, engineer or other
matched should be evaluated by visual and laboratory means.
professional with appropriate applicable experience, hereinaf-
Original color can be reasonably determined by visual exami-
ter referred to as the specialist.
nation of a freshly broken surface of a mortar sample.
3.1.10 tuckpointing—for purposes of this guide, synony-
6.3 Evaluate Masonry Materials—The physical properties
mous with repointing.
of masonry units should be assessed to ensure compatibility
with the repointing mortar.
4. Significance and Use
6.3.1 When required, the physical properties of the masonry
4.1 Repointing masonry improves weather resistance, re-
should be tested in accordance with Methods C67, C140, and
duces water penetration, maintains structural and visual integ-
C170, respectively.
rity, and prolongs the life of the building by allowing a mortar
joint to shed water and avoid the accumulation and penetration 6.3.2 For some repointing projects, sampling and testing of
of rainwater between mortar and masonry units. masonry units and materials is not permitted or necessary. In
4.2 This guide provides for the selection of the most such cases, a qualitative assessment of the physical properties
effective methods appropriate for repointing masonry based of materials can suffice. Such qualitative assessment should
upon the following parameters: include identification of the type of masonry materials and a
4.2.1 Determination of joints to be repointed. visual inspection of the condition of the materials. Literature
4.2.2 Evaluation of in-situ masonry. from the appropriate period can be reviewed for an indication
4.2.3 Evaluation of techniques for removal of mortar. of properties of the materials. When available, the original
4.2.4 Determination of appropriate repointing mortar. material specifications and relevant maintenance and repair
4.2.5 Selection of repointing mortar. work for the building should be reviewed.
E2260–03
7. Evaluation of Techniques for Removal of Mortar 8.3.3 Test areas should permit visual inspection and com-
parison to adjacent masonry surfaces that have not been
7.1 In determining the method of mortar removal, a stan-
repointed. Inspection should be performed under similar light-
dard should be established for joint preparation that limits the
ing and exposure conditions.
damage to masonry units and provides a proper substrate for
bonding of new mortar. Prior to beginning the work, potential
9. Selection of Repointing Mortar
techniques for mortar removal should be evaluated.
9.1 The repointing mortar should be selected based on the
7.2 Mortarremovalproceduresshouldattempttoremoveall
purpose of repointing and with consideration given to its
mortar from joints to the specified depth and to provide a
historic proportions and compatibility with masonry materials.
substrate to which the repair mortar can properly adhere.
Formulationoftherepointingmortarshouldnotbebasedonan
7.3 Mortar can be removed using various procedures. Tech-
inappropriate, previously installed pointing mortar.
niques including raking, chiseling, routing, and grinding, are
9.2 The selected repointing mortar should match the origi-
listed and described in Section 3. Combinations of these
nal mortar (if originally used) or exposed mortar unless it is
techniques can also be used.
determined that either is inappropriate for use.
7.4 On historic masonry, it is recommended that the most
9.3 Theselectedrepointingmortarshouldbetheappropriate
effective and least damaging technique be used as the method
color and texture as determined by the user of this guide and
of mortar removal.
exhibit the durability and performance desired. See 8.1.
NOTE 1—Handrakingaloneasatechniqueshouldonlybeusedifitcan
9.4 The visual matching of in-situ mortar with the repoint-
be determined that hand raking can be performed without causing damage
ing mortar may be desired but can be difficult to achieve. An
to masonry. If hand raking is determined to damage the masonry units,
acceptable match can require analysis of the in-situ mortar
other techniques of mortar removal shall be considered.
materials, trial mix proportions using new mortar materials,
7.5 Although some damage may be inevitable, careful joint and variations in placement and tooling of the repointing
preparation can help limit damage to masonry units.
mortar.Ifitisdesiredtomatchtheappearanceoftherepointing
7.6 It is the responsibility of the user of this guide to mortar to the in-situ mortar, the unsoiled color, determined by
evaluate the advantages and disadvantages of the various examining the interior surface of the mortar, should be
removal techniques as they relate to type and condition of the matched. Proposed repointing mortars should be installed and
evaluated in test areas, refer to Section 8.
masonry to be repointed.
9.5 The composition of the repointing mortar should be
7.7 The use of power tools is not recommended for joints of
designed and assessed to ensure compatibility of the physical
less than 3 mm, where the geometry of the joint limits access,
properties with the in-situ mortar and masonry units. Mortar
or where the masonry units are weak or friable.
composition may be evaluated in accordance with Method
7.8 Evaluate the method of mortar removal with regard to
C1324.
the structural and visual integrity of the masonry.
7.9 Technicians should be evaluated with regard to their
NOTE 2—Substantial disparity between the compressive strengths or
abilitytoremovein-situmortarwithoutdamagetothemasonry
otherphysicalpropertiesofthein-situmortarandtherepointingmortar,or
units.Ademonstration of their ability should be conducted and the repointing mortar and the masonry units can lead to spalling or other
distress of the masonry units.Acommon approach to ensure compatibility
approved on a test area representative of the work to be
of physical properties is to evaluate the composition of the in-situ mortar
performed.
and approximate the compressive strength of the mortar before selecting
the repointing mortar. The repointing mortar should have a similar or
8. Use of Mortar Samples and Test Areas
lower compressive strength and greater water vapor permeability than the
masonry units.
8.1 Samples of the proposed repointing mortar should be
prepared for comparison with the original mort
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