U.S. General Services Administration
Technical Procedures Disclaimer
Prior to inclusion in GSA’s library of procedures, documents are reviewed by one or more qualified preservation specialists for general consistency with the Secretary of Interior Standards for rehabilitating historic buildings as understood at the time the procedure is added to the library. All specifications require project-specific editing and professional judgement regarding the applicability of a procedure to a particular building, project or location. References to products and suppliers are to serve as a general guideline and do not constitute a federal endorsement or determination that a product or method is the best or most current alternative, remains available, or is compliant with current environmental regulations and safety standards. The library of procedures is intended to serve as a resource, not a substitute, for specification development by a qualified preservation professional.
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We’ve reviewed these procedures for general consistency with federal standards for rehabilitating historic buildings and provide them only as a reference. Specifications should only be applied under the guidance of a qualified preservation professional who can assess the applicability of a procedure to a particular building, project or location. References to products and suppliers serve as general guidelines and do not constitute a federal endorsement nor a determination that a product or method is the best alternative or compliant with current environmental regulations and safety standards.
PATCHING CRACKS IN BRICK MASONRY
PART 1–GENERAL
1.01 SUMMARY
A. This procedure includes guidance on repairing cracks or infilling small holes in brick masonry using a cementitious patching material.
B. See 01100-07-S for general project guidelines to be reviewed along with this procedure. These guidelines cover the following sections:
1. Safety Precautions
2. Historic Structures Precautions
3. Submittals
4. Quality Assurance
5. Delivery, Storage and Handling
6. Project/Site Conditions
7. Sequencing and Scheduling
8. General Protection (Surface and Surrounding)
These guidelines should be reviewed prior to performing this procedure and should be followed, when applicable, along with recommendations from the Regional Historic Preservation Officer (RHPO).
PART 2–PRODUCTS
2.01 MANUFACTURERS
A. Jahn Restoration Techniques and Research (Cathedral Stone Company)
B. Edison Chemical Systems, Inc.
2.02 MATERIALS
A. Cementitious patching material such as “M70 Stone Restoration Mortar” (Jahn Restoration), “Custom System 45” Edison Chemical Systems), or approved equal.
B. Clean, soft cloths
C. Clean, potable water
2.03 EQUIPMENT
A. Stiff natural bristle brushes
B. Trowel
C. Chisel
D. Hammer
E. Putty knife
PART 3–EXECUTION
3.01 ERECTION, INSTALLATION, APPLICATION
A. Remove all loose materials from cracked brickwork.
B. Widen crack to 1/8” wide and grout crack and any voids with a cementitious grout that is color matched to clean brick. The grout should be compatible in texture and porosity to the adjacent masonry. Tape joint to provide
a clean neat finished appearance.
C. Severely cracked brick associated with displaced masonry should be dismantled. Probe interior conditions and repair following an engineer’s evaluation. Rebuild brickwork to match existing bonding patterns and use
salvaged brick where possible and new brick to match existing color, texture and porosity.