Significance and Use

Repointing masonry improves weather resistance, reduces water penetration, maintains structural and visual integrity, and prolongs the life of the building by allowing a mortar joint to shed water and avoid the accumulation and penetration of rainwater between mortar and masonry units.

This guide provides for the selection of the most effective methods appropriate for repointing masonry based upon the following parameters:

Determination of joints to be repointed.

Evaluation of in-situ masonry.

Evaluation of techniques for removal of mortar.

Determination of appropriate repointing mortar.

Selection of repointing mortar.

Establishing the method of execution of the work.

Visual inspection of the work.

1. Scope

1.1 This guide applies only to existing historic masonry construction. For purposes of this guide historic masonry is intended to refer to buildings that have significant historic, architectural, cultural or social meaning and are constructed of masonry materials. Similar techniques and evaluation should be employed for non-historic masonry, but are not addressed in this guide.

1.2 This guide outlines procedures for repointing historic masonry and is intended to provide guidelines for the user to establish project-specific requirements for repointing of historic masonry.

1.3 This guide only pertains to masonry units: brick, terra cotta, stone, cast stone, and concrete brick laid in mortar, and may or may not be appropriate for other masonry units.

1.4 This guide addresses repointing (tuckpointing) as defined in 3.1.3.

1.5 When considering repointing, especially on masonry of artistic, architectural, cultural, or historical significance, guidance from a specialist experienced in historic masonry and repointing should be sought.

1.6 This guide does not address pointing styles or profiles used on masonry or the methods of producing them.

1.7 Additional repairs that may impact the structural integrity of the masonry may necessitate that a structural stability analysis be completed prior to the execution of any work.

1.8 Following this guide may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory requirements prior to use.

2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

ASTM Standards

C67 Test Methods for Sampling and Testing Brick and Structural Clay Tile

C140 Test Methods for Sampling and Testing Concrete Masonry Units and Related Units

C170 Test Method for Compressive Strength of Dimension Stone

C270 Specification for Mortar for Unit Masonry

C780 Test Method for Preconstruction and Construction Evaluation of Mortars for Plain and Reinforced Unit Masonry

C1072 Test Methods for Measurement of Masonry Flexural Bond Strength

C1324 Test Method for Examination and Analysis of Hardened Masonry Mortar

E631 Terminology of Building Constructions

E1857 Guide for Selection of Cleaning Techniques for Masonry, Concrete, and Stucco Surfaces

Keywords

historic masonry; mortar; pointing; repointing; tuckpointing; Brick; Cast stone (architectural); Historic masonry/preservation; In-situ inspection/analysis; Mortar; Pointing; Removal of mortar; Repointing; Stone; Terra cotta; Tuck pointing

ICS Code

ICS Number Code 91.080.30 (Masonry)

DOI: 10.1520/E2260-03R12

ASTM International is a member of CrossRef.

ASTM E2260