Specification:In-kind replacement of deteriorated stone masonry

__NUMBEREDHEADINGS__

=GENERAL=

DESCRIPTION
 This specification has been developed for use on historic properties (defined as any district, site, building, structure, or object that is listed in or eligible for listing in the National Register of Historic Places) and provides an overview of accepted practices. Site-specific specifications, when appropriate, will be provided by the Architect. All work described herein and related work must conform to the Secretary of the Interior’s Standards for the Treatment of Historic Properties. The Contractor shall provide all labor, materials, equipment, and operations required to complete the rehabilitation work indicated herein. All work described herein and related work must have the approval of a Cultural Resources Manager, Conservator, Historic Architect, or other professional who meets the standards outlined in the Secretary of the Interior’s Standards – Professional Qualifications Standards pursuant to 36 CFR 61. Such person is referred to in this document as the Architect. 

SECTION INCLUDES
 Assessment of deteriorated units and criteria for replacement Stone masonry replacement procedure including selection, fabrication, and installation. 

RELATED SECTIONS
<ol type="A"> Section 04100 – Historic Mortar</li> Section 04400 – Stone</li> Section 04500 – Masonry Restoration</li> Section 04510 – Masonry Cleaning</li> Section 07900 – Joint Sealers</li> </ol>

SUBMITTALS
The Contractor shall submit to the Architect: <ol type="A"> A detailed schedule of the areas for repair, including an assessment of the problem areas, historic mortar analysis, and stone identification, and a detailed procedure for masonry repair for approval.</li> Product data for all manufactured masonry restoration materials, including stone materials, adhesives, and mortar components. Manufacturer’s product data shall include certification of compliance with specified standards and instructions for handling, storage, and installation of the material. The Contractor shall also submit Material Safety Data Sheets for each material if available.</li> Fabricator’s shop drawings for new fabricated-stone-masonry units to be provided. Shop drawings shall include all dimensions, piece, marks, anchoring. and installation details. Indicate surface finish and special tooling required.</li> Samples of the following masonry repair and replacement materials for approval of color and texture match. No masonry restoration work shall proceed until all samples are approved.  Cured pointing mortar for stone masonry: the Contractor shall prepare portable samples using drywall channel or similar material of the approximate width of a mortar joint. Once a matching mortar color is achieved, placement of on-site mock- ups may begin.</li> Replacement stone materials: The Contractor shall provide at least three samples (minimum size 6x6 inches) of each type of replacement stone required for the project. Samples shall illustrate the full range of color variation and figuring to be expected. If stone units required for the project are larger than 12x12 inches, the Contractor shall provide larger samples to illustrate true appearance of the fabricated units.</li> </ol> </li> </ol>

QUALITY ASSURANCE
<ol type="A"> Work Experience: The Contractor to perform the work in this section shall have a minimum of ten (10) years experience in historic masonry restoration and shall have successfully completed at least three projects of similar scope within the previous five years. He/she shall demonstrate a working knowledge of The Secretary of the Interior’s Standards for the Treatment of Historic Properties with Guidelines for Preserving, Rehabilitating, Restoring & Reconstructing Historic Buildings.</li> The Contractor shall not change sources or manufacturers of stone or mortar materials during the course of the work without prior Architect approval.</li> Warranty: The Contractor shall provide a warranty in writing against defects in material and installation for a period of five (5) years.</li> </ol>

MOCK-UPS
<ol type="A"> The Contractor shall provide samples of stone and mortar matches for stone masonry restoration for approval by the Architect of color and texture. After approval the Contractor shall prepare test panels: <ol> <li>Stone Masonry Restoration: All personnel proposed for work on the project shall prepare 3x3-foot samples demonstrating stone restoration techniques, including mortar removal, repointing, and stone replacement. Personnel whose mock-up panels are rejected shall not be utilized for masonry restoration work.</li> <li>Mock-ups will be reviewed after the mortar removal and again after completion of repointing.</li> <li>Mock-ups shall display the full range of materials and workmanship required for completion of the project for approval by the Architect.</li> <li>Color matching: Contractor shall match existing mortar color(s). The Contractor shall place the initial sample panel using the mix from the approved sample. The sample panel must be cured in the same manner as is expected for the work based on anticipated temperatures.</li> </ol> </li> <li>The Contractor shall prepare up to three additional mock-ups of each mortar, joint type, and mortar color without further compensation. Approved test panel(s) shall become part of the work and shall serve as the quality standard for all subsequent work.</li> </ol>

DELIVERY, STORAGE, AND HANDLING
<ol type="A"> <li>Materials shall be delivered to the site in original packaging, unopened, with manufacturer’s name and product identification thereon. Cementitious materials shall be protected from contamination by foreign matter and deterioration by moisture or temperature. Contaminated or deteriorated material shall not be used. Products stored longer than six months shall not be used.</li> <li>Masonry materials shall be stored in such a manner as not to interfere with the operation and daily maintenance of the facility. Proposed storage locations shall be approved by the Architect.</li> <li>The Contractor shall store liquids at temperatures between 40 and 85 degrees. Do not allow liquids to freeze.</li> <li>Masonry units shall be stored off the ground, protected from the weather, and kept free from exposure to contaminants such as mud, dust, or materials that could cause staining.</li> <li>Transport and handle masonry stone units in such a manner as to prevent chipping and breakage. Locate storage piles, stacks, or bins to avoid and protect material from heavy and unnecessary traffic. The Contractor shall store stone slabs on pallets on edge.</li> <li>The Contractor shall coordinate stone deliveries with the construction schedule and sequence. Stone materials shall be delivered in an order consistent with the order of installation at the project site to avoid unnecessary handling of materials.</li> </ol>

PROJECT / SITE CONDITIONS
<ol type="A"> <li>Normal conditions for the work of this Section shall be defined as when the air and surface temperatures are 40 degrees F and rising or less than 90 degrees F and falling. When temperatures are predicted to rise above or fall below this temperature range, the Contractor may proceed using approved hot and cold weather procedures as defined by the Masonry Institute of America. Work shall not commence when rain, snow, or below-freezing temperatures are expected within the next 24 hours. All surfaces shall be free of standing water, frost, and ice.</li> <li>The Contractor is responsible for protecting existing adjacent materials and surfaces during the execution of the work, and shall provide all necessary protection and follow all necessary work procedures to avoid damage to existing material assemblies not a part of the work in this Section. The Contractor shall: <ol> <li>Minimize levels of dust during mortar removal and masonry repointing operations.</li> <li>Protect open copings, reglets, and other vulnerable areas from water penetration to prevent leakage during the course of the work. Open areas shall not be left exposed overnight or when inclement weather is predicted.</li> <li>Temporarily remove and store metal downspouts during masonry restoration work. Install temporary drainage leaders if required. Reinstall immediately upon completion of work in the immediate area. Protect open boots at grade from accumulation of masonry debris.</li> <li>Protect existing gutters and gutter outlets from damage and accumulation of mortar debris during restoration of roof elements.</li> <li>Protect window sashes and frames with plywood or other sturdy barrier during repointing and repair of masonry around window openings.</li> <li>Protect the existing roof surfaces from damage during the course of the masonry restoration work. Repair all damage to wood and metal roofing, gutters, flashings, etc., to the satisfaction of, and at no additional cost to, the Owner.</li> <li>Remove and store light fixtures, signage, security devices and miscellaneous appurtenances from masonry surfaces to be repointed. Provide temporary protection for exposed fixture boxes.</li> </ol> </li> <li>The Contractor shall provide visible barriers and / or warning tape around the perimeter of the work area for visitor protection. Nearby vehicles and adjacent structures shall be protected from damage during the course of the work.</li> <li>Stone, brick, mortar, waste material, packaging, and other debris associated with the masonry work shall be disposed of in accordance with local, state, and federal environmental regulations. The Contractor shall remove debris from masonry restoration work from the site on a daily basis and at the completion of the work.</li> <li>The Contractor shall coordinate masonry repairs with the other trades involved in exterior and interior restoration work, including but not limited to masonry cleaning, sealing, and painting.</li> </ol> =PRODUCTS=

MATERIALS
<ol type="A"> <li>Pointing Materials <ol> <li>Lime: ASTM C-207, Type S</li> <li>Portland cement: ASTM C-150, Type I, non-staining and without air entrainment. Gray and white portland cement may be combined as required to match existing mortar.</li> <li>Sand: ASTM-C-144, free of clay, silt, soluble salts and organic matter and shall match the color and texture of the original mortar sand.</li> <li>Water: Potable and free of deleterious amounts of oil, soluble salts, alkali, acids, organic impurities, or other substances that may impair the strength or bond of the finished mortar.</li> <li>Mortar colorant, if required to match the color of the existing mortar, shall be a standard product manufacture by Solomon Grind-Chem Service, Medusa, or other approved manufacturer.</li> </ol> </li> </ol>

MIXES
<ol type="A"> <li>Mortar mixes shall be appropriate the strength and hardness for the masonry units and existing mortar. The mix shall match the composition, color, and texture existing mortars. Refer to Section 04100 – Historic Mortar.</li> </ol>

IN-KIND STONE REPLACEMENT
<ol type="A"> <li>Architectural stone: New stone must be compatible with the existing stone and match in color and texture. Any chosen product must be justified accordingly and approved by Architect. <ol> <li>Granite: ASTM C615</li> <li>Marble: ASTM C503</li> <li>Sandstone: ASTM C616</li> <li>Limestone: ASTM C568</li> <li>Slate: ASTM C629</li> <li>Other varieties of material, such as fieldstone, that are not subject to referenced standards shall be selected for their soundness, color, and texture match to the original masonry.</li> </ol> </li> <li>One supplier for approved stone shall be used for completion of the work.</li> <li>Fabrication: <ol> <li>New ashlar stone units shall be fabricated in accordance with approved shop drawings. Fabricated units shall match all dimensions indicated on the approved shop drawings within a tolerance of +/- ? inch in 12 inches.</li> <li>The Contractor shall cut masonry units with a motor-driven saw designed to cut masonry with clean, sharp, unchipped edges.</li> <li>Exposed surfaces shall be tooled by hand or machine as required to match the original stone.</li> <li>The Contractor shall provide slots or holes for anchors as indicated on the shop drawings.</li> </ol> </li> </ol>

ACCESSORY MATERIALS
<ol type="A"> <li>Stainless-steel pins for anchoring patches shall be Type 304 or 316 stainless-steel all-thread rods, ¼ inch diameter. Length shall be as required by the depth of the patch. All other embedments such as eye bolts to be used for anchoring reinforcing pins and wire shall be stainless steel.</li> <li>Stainless-steel rods for stitching vertical cracks shall be Type 304 or 316 stainless-steel all- thread rods, ¼ inch diameter. Length shall be approximately 24 inches or as required to span crack 12 inches on either side.</li> <li>Epoxy adhesive for embedding anchors and pins shall be a high modulus epoxy resin conforming to ASTM C-881, Type I, II, IV, and V, Grade 3 epoxy resin adhesives.</li> </ol> =EXECUTION=

GENERAL
<ol type="A"> <li>Masonry cleaning shall be completed prior to masonry repair and repointing. New replacement materials and mortars shall be matched to the color of the cleaned stone.</li> <li>The Contractor shall examine areas and conditions under which masonry restoration is to be performed and notify the Architect of any conditions detrimental to the proper and timely completion of the work. Do not commence work until all unsatisfactory conditions have been adequately corrected.</li> <li>Masonry repairs shall be completed prior to beginning masonry repointing.</li> </ol>

IN-KIND REPLACEMENT OF HISTORIC STONE
<ol type="A"> <li>Carefully dismantle selected areas of masonry where designated on the Drawings, and dismantle adjacent assemblies as required for access to the designated masonry, salvaging components for reuse to the greatest extent possible. The Contractor shall permanently label individual masonry units to remain on a concealed face to allow reassembly in original locations.</li> <li>Rake or grind mortar from joints to the greatest extent possible before attempted removal of the building stones. Avoid excessive prying against the arrises of the masonry units to remain to avoid spalling and chipping. Deteriorated masonry units to be replaced may be broken out using pneumatic chisels or grinders.</li> <li>Clean old mortar and sealants from masonry units to be reused.</li> <li>Install new masonry units where indicated to match the depth of the surrounding walls. Patch in kind and/or reinstall to match adjacent materials as required to complete the installation. The Contractor shall: <ol> <li>Cut units as required to provide bonding pattern to match the existing masonry and to fit adjoining work neatly. Use full units without cutting wherever possible.</li> <li>Lay masonry units straight, plumb, and true to line and level in full mortar bed with full coverage for horizontal bed and vertical head joints. Rake back all mortar joints ½ inch for installation of pointing mortar.</li> <li>Install stainless-steel pins or anchors as indicated on the approved shop drawings to secure stone units to the existing substrate. Pins shall penetrate a minimum of one third the thickness of the stone to be installed but under no circumstance be allowed to penetrate beyond half the depth of the stone.</li> <li>The diameter of the holes for stainless steel anchor pins shall be drilled ? inch greater than the diameter of the pins. The use of hammer drills is NOT permitted. Anchor pins in specified setting adhesive.</li> <li>Use lead, slate, or plastic shims of the thickness required to maintain the required joint width. The use of wood shims is NOT permitted.</li> </ol> </li> <li>Brush, vacuum, or flush joints to remove all dirt and loose debris. Dampen joints prior to pointing to prevent suction of moisture from the pointing mortar.</li> <li>Where finish mortar joints are indicated, install pointing mortar in ¼-inch-thick layers, allowing each layer to reach thumbprint hardness before applying the succeeding layer. When the final layer of mortar is thumbprint hard, tool joint to match existing profile.</li> <li>The Contractor shall keep joints damp for 48 hours after pointing.</li> </ol>

FINAL REPORT
The Contractor shall: <ol type="A"> <li>Revisit the site with the Architect and compare the finish and color of the repair to see if the desired affect has been achieved after the brick repairs have been executed and new mortar has cured at least 30 days.</li> <li>Document the work and finished product with photographs.</li> <li>Provide a written summary of the project and results upon final inspection and approval. The summary shall outline steps taken or new findings not addressed in the initial documentation.</li> </ol>