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.
This general checklist is an aid for inspecting the condition of stone. It should be used as a supplement to the following:
- “Marble: Characteristics, Uses and Problems”
- “Granite: Characteristics, Uses and Problems”
- “Limestone: Characteristics, Uses and Problems”
NOTE: THE PRESENCE OF ANY OR SEVERAL OF THE CONDITIONS LISTED IN THE FOLLOWING CHECKLIST IS AN INDICATION OF STONE PROBLEMS. AN EXPERIENCED CONSERVATOR OR MASONRY EXPERT MAY BE NEEDED TO DIAGNOSE ACTUAL CAUSES OF THE PROBLEMS AND SELECT OR PLAN AN APPROPRIATE COURSE OF ACTION.
Assessments should address each type of stone present if multiple types exist.
- Identify the stone type.
- Examine the overall surface condition and appearance considering elevation/exposure factors.
- Note any staining.
- Note nature and color of staining (i.e. orange tains, green stains, etc.)
- Note extent and location of staining or crusting from oxidations.
- Inspect structural soundness of the stone. Note extent and location of:
- Cracks
- Settling
- Block Movement
- Pointing failure
- Repairs
- Moisture
- Examine the condition of caulking. Note nature, location and extent of:
- Flaking
- Powdering
- Leaking
- Distortion
- Failure/absence
- Cracks
- Examine the condition of coatings. Note nature and location of any surface coatings. Look for:
- Pigment residue
- Reservoir appearance
- Partial erosion
- Cracks and crazing of coating
- Cloudiness
- Gilding
- Note the location and condition of areas where water collects and ponds. Look for:
- Standing water
- Streaking
- Pockets and perforations
- Note any loss of finish surface as evidenced by flaking or peeling.
- Peeling and flaking usually follow uncorrected efflorescence or sub-florescence and represent a more advanced stage of failure.
- It is likely that some degree of rust or corrosion will be evident in areas left unprotected as a result of coatings loss through flaking.
- Note extent and location of peeling and/or flaking.
- Is it localized or general?
- Note any areas showing signs of erosion and/or wear.
- Note nature and location of any wear or erosion.
- Distinguish between erosion caused by environmental factors and normal exposure, versus that caused by human factors such as touching or vandalism.
- Carefully monitor and record all noted areas of erosion and wear, and notes on the location of eroded areas will aid in planning for the protection of the stone.
- Note the presence of graffiti.
- Identify the type of material used, such as paint, grease, lipstick, marker, scratches, etc.
- Note the general pattern and area of graffiti.
- Note any structural and/or mechanical problems.
- Examine surfaces for evidence of movement, cracks and breaks in the surface. Look for:
- Hairline cracks/Crevices. Are they active?
- Structural Cracks. Are they active? Many need monitoring (see 04200-02-S “Monitoring and Evaluating Cracks in Masonry”)
- Broken and/or missing pieces.
- Damaged joints.
- Examine surfaces for evidence of movement, cracks and breaks in the surface. Look for:
- Note nature and location of any wear or erosion.