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.
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.
- This procedure includes guidance on patching small chips and holes in granite. This may include patching small holes in granite left behind with the removal metal bolts and fasteners from the stone.
- See 01100-07-S for general project guidelines to be reviewed along with this procedure. These guidelines cover the following sections:
- Safety Precautions
- Historic Structures Precautions
- Quality Assurance
- Delivery, Storage and Handling
- Project/Site Conditions
- Sequencing and Scheduling
- 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).
- American Society for Testing and Materials (ASTM), www.astm.org
- Two part polyester resin adhesive colored to match existing granite such as "Akemi Transparent" knife grade (Akemi), or approved equal; 15-30 minute cure at 70 degrees F.; can be applied at temperatures as low as 40 degrees F.
- Permanent coloring agent as required, compatible with adhesive, and as recommended by adhesive manufacturer.
- Clean, potable water
- Stiff bristle brushes (natural fiber or nylon bristle)
- Polyethylene plastic mixing vessel for mixing adhesives and patching mortar
- Razor blade(s)
3.01 ERECTION, INSTALLATION, APPLICATION
- Remove loose dirt and debris from the hole and the surrounding stone surface using a stiff bristle brush. Flush with clean, potable water if necessary and allow to dry.
- Mix patching material following manufacturer's instructions and recommendations. Mix coloring agent with mastic before adding hardener. Mixes should be tested to determine finish color after curing, to achieve best color match with surrounding stone.
- Apply patching material to stone following manufacturer's instructions.
- . When the patching material becomes rubbery, carefully remove excess material using a razor blade. Finish patch surface to match surrounding stone surfaces.
- . Any patches determined unacceptable will be removed and refilled as directed by the Regional Historic Preservation Officer. Unacceptable patches include those showing separation at the edges and/or hairline cracking.