Repointing Mortar Joints in Historic Masonry Buildings

Famous Masonry Buildings

The Roman Colloseum Philadelphia City Hall

Identifying the Problem before Repointing

Ageing of the material, water infiltration, molding, aggressive environment

Examination of deterioration degree

Tracking markings for evolution in time of discontinuities

Tests for finding the proper mortar

Finding an Appropriate Mortar Match

The preparation of the probationary mortarsThe preparation of the probationary mortars

Preparation of joints for repointing using a hammer and a chisel

Preparations

Preparations

Cleaning of the joints with compressed air

Execution of work

This mortar has the proper consistency for repointing historic brick.

This early 19th century building is being repointed with lime mortar.

Execution of work

Masons practice using lime putty mortar to repair historic marble.

Repointing of mortar

Adequate Inadequate

Selected Reading

Ashurst, John & Nicola. Practical Building Conservation. Vol. 3: Mortars, Plasters and Renders. New York: Halsted Press, a Division of John Wiley & Sons, Inc., 1988.

Cliver, E. Blaine. "Tests for the Analysis of Mortar Samples." Bulletin of the Association for Preservation Technology. Vol. 6, No. 1 (1974), pp. 68-73.

Coney, William B., AIA. Masonry Repointing of Twentieth-Century Buildings. Illinois Preservation Series. Number 10. Springfield, IL: Division of Preservation Services, Illinois Historic Preservation Agency, 1989.