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.
PART 1–GENERAL
1.01 SUMMARY
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This procedure includes guidance on embedding threaded rods in epoxy or polyester resin in holes drilled into brick masonry walls to provide anchors for attachment to hardware connected to the framing of the building.
CAUTION: THIS PROCEDURE CAN DAMAGE AND/OR HAVE AN ADVERSE EFFECT ON HISTORIC MASONRY IF NOT PLANNED AND IMPLEMENTED PROPERLY.CONSULT THE REGIONAL HISTORIC PRESERVATION OFFICER FOR APPROVAL BEFORE PERFORMING THIS TYPE OF WORK TO ENSURE THAT THE MOST UNOBTRUSIVE RESULTS WILL BE OBTAINED. -
See 01100-07-S for general project guidelines to be reviewed along with this procedure. These guidelines cover the following sections:
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Safety Precautions
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Historic Structures Precautions
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Submittals
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Quality Assurance
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Delivery, Storage and Handling
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Project/Site Conditions
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Sequencing and Scheduling
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General Protection (Surface and Surrounding)
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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
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Abatron, Inc.
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Sika Corporation
2.02 MATERIALS
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Resin: The resin shall be a two-component, structural epoxy or polyester resin adhesive. The components shall be pre-measured in separate cartridges.
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Threaded Rods: Threaded rods shall be sized according to need and loading requirements. Consult with structural engineer and Regional Historic Preservation Officer (RHPO).
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Screen Tube: Screen tubes shall be 7/8 inch diameter, approximately 28 wire per inch square mesh screen.
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Mixing Nozzle: The resin components may be automatically mixed by a nozzle that is secured to the component cartridge.
2.03 EQUIPMENT
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Electric drill with mixing paddle provided by adhesive manufacturer.
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Pail in which to hand mix adhesive.
PART 3–EXECUTION
3.01 ERECTION, INSTALLATION, APPLICATION
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Holes:
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The drill holes should be sized according to the rod used. Typically, the hole shall be no greater in diameter than 1/8-inch or 1/4-inch (depending on the adhesive used) larger than the pin to be embedded, and ten to fifteen bar diameters deep.
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Drill shall be non-impact type rotary drill with a masonry bit.
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Clean holes with high pressure air and a stiff nylon brush.
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Installation:
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Verify the rod length as appropriate for the depth with at least 1-1/2” projection. NOTE: Projection may be more or less depending on use.
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If using automatic pressure-injection equipment, resin shall be automatically measured and mixed in the mixing nozzle.
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If mixing by hand, mix each component by volume as directed by manufacturer into clean pail. Components shall be used straight, without any additives. Mix thoroughly for time specified by manufacturer with low-speed drill (400-600 rpm) fitted with appropriate paddle. Blend until uniform color is achieved.
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Place the resin into the screen tube. Completely fill the screen tube. Begin placement at the end of the screen and withdraw the nozzle as the screen fills.
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Insert the screen tube and resin into the hole.
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Slowly insert the threaded rod into the resin to the full depth of the hole.
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Do not disturb the anchor until the adhesive has cured. Follow manufacturers instructions.
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No gaps shall be visible between the rod and the masonry.
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Conform with all requirements of the ICBO Research Report for the product, Manufacturers’ Recommendations, and all applicable Building and Safety Guidelines. These referenced documents shall be on the job and referred to when the work of this Section is underway.
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3.02 ADJUSTING/CLEANING
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Remove spills and excess adhesive with absorbent material, flush with water.
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Uncured material can be removed with solvent as recommended by adhesive manufacturer.
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Do not allow excess material to cure as cured adhesive can only be removed mechanically.