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.
A. This procedure includes guidance on removing built-up floor coatings from terrazzo floors.
B. 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).
A. National Terrazzo and Mosaic Association, Inc.(NTMA)
3166 Des Plaines Avenue,
Des Plaines, IL 60018,
800/323-9736 or 708/635-7744, FAX 708-635-9127.
1.03 SYSTEM DESCRIPTION
A. Performance Requirements: The objectives for terrazzo cleaning are to remove dirt, grime and coatings from the surfaces without damaging the underlying material and to give all the terrazzo a clean uniform appearance without blotches.
- Sample panels for cleaning and terrazzo patching shall be prepared for approval and shall establish a standard for all terrazzo work. The locations and types of control samples are to be indicated on a plan, with a photograph of each control sample to be submitted to the Contracting Officer's representative. No work shall commence until written approval for the control samples has been obtained from the Contracting Officer's representative.
- The Contractor shall clean sample panels 2'-0" by 2'-0" in area, on each color and type of terrazzo, for approval by the Contracting Officer's representative. Locations of sample panels to be selected by the Contracting Officer's representative.
1.05 QUALITY ASSURANCE
A. Regulatory Requirements:
- Comply with specified provisions and recommendations of the National Terrazzo and Mosaic Association, Inc. (NTMA Standards).
- Comply with municipal and Federal regulations governing all work included in this section and including, but not limited to, cleaning, waste disposal and protection to adjacent properties.
- Contractor: The work shall be performed by a firm possessing a minimum of five (5) years of specialized experience in the restoration and cleaning of historic architectural terrazzo, similar to that which is required in this project. The Contractor shall submit to the Contracting Officer's representative references of previous work, justifying the firm's experience. The Contracting Officer's representative reserves the right to approve or disapprove the use of the Contractor contingent upon their experience.
- NOTE: The quality of the work is highly dependent on the competence of the Contractor because it is not possible to anticipate every variation encountered int he surfaces, job conditions and methods used.
- Where current codes cannot be complied with, and/or construction limitations (including deterioration of existing substrate) are such that the intended finish cannot be achieved, notify the Regional Historic Preservation Officer (RHPO) for clarification and/or decision prior to proceeding with the work.
- Mock-ups: Strip and clean 20 square feet of each terrazzo type for review by RHPO before stripping and cleaning all the terrazzo.
A. General Paint and Chemical Company - Division of Cotter and Company
Chicago IL 30314
A. Water: Potable, non-staining and free of oils, acids, alkalis and organic matter.
B. Interior Terrazzo Floor Sealer: Colorless slip and stain resistant non-penetrating sealer with pH factor between 7 and 10, that does not affect the color or physical properties of the existing terrazzo surface.
C. Cleaning Agents - (Built-Up Coatings): A non-ammoniated liquid wax stripper/floor cleaner, such as "Tru-Test Floor Stripper FS10" (General Paint and Chemical Company), or approved equal.
A. Wood scrapers
B. Fiber bristle brushes
- Take all necessary precautions and measures to protect all surrounding materials from damage that might be incurred during the terrazzo restoration work describe din this outline specification. Any damage caused by the Contractor to other materials is unacceptable and shall be repaired or replaced by the Contractor to the satisfaction of the Contracting Officer's representative, at not cost to the Government.
- Improper use of chemicals may constitute a health hazard. Refer to manufacturer's Material Safety Data Sheets for hazard data, special protection, for use and precautions to be taken in handling and storage. Comply with manufacturer's recommendations for proper use of chemicals.
3.02 ERECTION, INSTALLATION, APPLICATION
A. Strip built-up floor coatings from the terrazzo flooring by applying a dilute cleaner (such as Tru-Test Stripper FS.10). Let dwell for 5 to 20 minutes depending on test trial results, scrub with fiber bristle brush, a mechanical floor machine, or white nylon pad, and rinse with low pressure cold water (less than 100 psi).
B. Do not use metal brushes. Repeat application for stubborn build up. Do not allow cleaner to dry on the floor. A testing program monitored by the Contracting Officer's representative should be undertaken to verify procedures, methods and dwell times.
C. Apply penetrating type sealer to reduce the porosity of the terrazzo and increase its resistance to acid and alkalis. Follow manufacturer's instructions.