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040120MSBA Accelerated Repair Program RK Finn/Ryan Road and Leeds Elementary Schools Northampton, Massachusetts 04 01 20 - 1 SECTION 04 01 20 MASONRY RESTORATION AND REPAIR – LEEDS SCHOOL FILED SUB BID REQUIRED PART 1 - GENERAL 1.01 Filing Sub-Bid A. Sub-Bids for Work under this Section shall be for the complete Work required hereunder and shall be filed in a sealed envelope with the Awarding Authority before the time and date and at the location indicated in the Instructions to Bidders and at that time will be publicly opened and read aloud. B. Procedure for filing Sub-Bids shall be as set forth in the Instructions to Bidders contained in this Project Manual and shall conform to all requirements of the Commonwealth of Massachusetts General Laws, Chapter 149, as amended to date. C. Every Sub-Bid submitted for Work under this Section shall be on a form furnished by the Awarding Authority as required by Section 44G of Chapter 149, as amended, which form is required to be completely filled in. A sample bid form for Subcontractors is contained in this Project Manual and the bid form to be used in filing a Sub-Bid is available at the office of the Architect. D. Every Sub-Bid filed with the Awarding Authority shall be accompanied by bid security in the form and amount stipulated in the Instructions to Bidders. E. The Work to be done under this Section is shown on the Drawings and as specified herein. 1.02 General A. General Conditions, Supplementary Conditions and applicable parts of Division 1 form a part of this specification and the Contractor shall consult them in detail for instructions. 1.03 The drawings on which this Contract is based are listed in Section 00860. Consult all drawings, note all conditions that may affect the work, and care for same executing this contract. 1.04 Reference Drawings: The Work of this Filed Sub-Bid is shown on the following Contract Drawings: A1.0, A1.1, A1.3, A2.3, A2.14, A2.15, A2.16, A2.17, A3.0, A3.1, A3.4, A3.6, A3.7, A3.8 and A3.14, (Leeds Elementary Schools). 1.05 The Contractor under this Section shall provide all materials, labor, equipment and appliances required to do all the masonry restoration and related work including but not limited, to the following: A. Refer to the drawings for specific work notes. 1. Scaffolding for all the work of this section. 2. Repair and replace areas of existing cracked brick and precast. MSBA Accelerated Repair Program RK Finn/Ryan Road and Leeds Elementary Schools Northampton, Massachusetts 04 01 20 - 2 3. Clean and pressure wash existing brick surfaces where indicated. 4. Re-caulk existing joints where indicated. 5. Install new through-wall flashings in existing brick masonry / glass block cavity walls where indicated. This shall include the selective demolition and reinstallation of new brick masonry / glass block affected by the installation of the new through-wall flashing. 6. Clean metal work where indicated. 7. Thru-wall flashing, weep holes, metal counter flashings and ties at new exterior walls 8. Cavity wall drainage mats / mortar net. 9. Reinforcing steel and wire joint reinforcing. 10. Rake and new sealant for masonry joints where indicated 11. All staging, scaffolding and hoisting for the work of this Section. 1.06 Related Sections A. Section 02 41 19 - Selective Demolition B. Section 01 27 00 – Unit Prices C. Section 06 10 00 - Rough Carpentry D. Section 07 53 23 - Roofing E. Section 07 92 00 – Joint Sealants 1.07 Submittals A. Submit for approval in accordance with the requirements of Section 01300, the following: 1. Manufacturers brochures and product data for all manufactured and purchased products. 2. Actual color samples of: a. Caulking b. Mortar Mix c. Brick Samples proposed for Repair to install through wall flashings. Individual brick masonry units for each type of masonry used with manufacturer's certificate of compliance with project specifications. Units shall show the extreme variations in colors, textures, finishes and dimensions and shall match existing color and texture of adjacent masonry surfaces. d. Glass Block Samples proposed for repair of through wall flashings. Submit two (2) glass block units of each type specified, showing size, design and pattern of MSBA Accelerated Repair Program RK Finn/Ryan Road and Leeds Elementary Schools Northampton, Massachusetts 04 01 20 - 3 faces. Submit representative samples of (panel reinforcing), (panel anchors), (expansion strips), and (sealant). 1. Test Reports —Fire Tests Submit documents verifying glass block units are classified for a 1 hour fire exposure according to ASTM E2010, Underwriters Laboratories of Canada CAN 4-S106-M80, UL® 9, or NFPA 257 “Fire Tests of Window Assemblies.” All such glass block unit cartons shall carry appropriate UL® labels. e. Metal Flashing B. Sample Panels (Each Mortar Type) 1. Construct at the site, mock-up panels as requested by the Architect for face brick and glass unit masonry. Panel shall show brickwork, joint finishing and construction methods to be incorporated into the work. Incorporate ties, flashing and weeps. All masonry work constructed subsequently shall conform to the approved panel. Construct new panels as necessary until approved by the Architect. 1.08 Test Panels A. Before full scale application, review manufacturer's product data sheets to determine the suitability of each product for the specific surfaces. Apply each restoration cleaner and paint stripper to test panels to determine dilution rates, dwell times, number of applications, compatibility, effectiveness, application procedures, effects of pressure rinsing, and desired results. B. Apply restoration cleaners and paint strippers to test panels in accordance with manufacturer's instruction. Allow 48 hours or until test panels are thoroughly dry, before evaluating final appearance and results. Do not begin full scale application until test panels are inspected and approved by the Architect. 1. Size: Minimum 4 fee by 4 feet each. 2. Locations: As determined by the Architect. 3. Restoration Cleaners: Number of test panels as required to completely test each restoration cleaner with each type of substrate and with each type of material or stain to be cleaned. 4. Paint Strippers: Number of test panels as required to completely test each paint stripper with each type of substrate and with each type of coating or paint to be stripped. C. Test all cleaning effluents generated by the restoration cleaning and paint stripping of the test panels to determine any hazardous characteristics. Comply with applicable federal, state, and local environmental regulations regarding testing, handling, treatment, containment, collection, transport, disposal, and discharge of hazardous wastes. D. Retain and protect approved test panels in undisturbed condition during the work of this section, as a standard for judging the restoration cleaning work. 1.09 Quality Assurance MSBA Accelerated Repair Program RK Finn/Ryan Road and Leeds Elementary Schools Northampton, Massachusetts 04 01 20 - 4 A. Applicator Qualifications: 1. Experienced in the application of the specified products. 2. Employs persons trained for the application of the specified products. B. Pre-Application Meeting: Convene a pre-application meeting two (2) weeks before the start of exterior masonry restoration cleaning. Require attendance of parties directly affecting work of this section, including the Contractor, Architect, applicator and ProSoCo representative. Review environmental regulations, test panel procedures, protection of surrounding areas and non-masonry surfaces, surface preparation, application and coordination with other work. C. Through-wall flashing installation in existing masonry wall procedures: Provide application and method procedures including bracing and shore for installation of new through wall flashings in existing masonry walls. D. Product Data: Provide manufacturer's product data sheets on all products to be used for the work. E. Applicator Qualifications: Submit qualifications of applicator. 1. Certification that applicator is experienced in the application of the specified products. 2. List of recently completed exterior masonry restoration cleaning projects, including project name and location, names of owner and architect, and description of cleaning products used, substrates, environmental regulations and application procedures. F. Environmental Regulations: Describe testing, handling, treatment, containment, collection, transport, disposal and discharge of hazardous wastes and cleaning effluents. Describe any hazardous materials to be cleaned from substrates. Describe types of coatings and paints to be stripped from substrates. Indicate any lead-based paints. Submit applicable local environmental regulations. G. Protection: Describe methods for protecting surrounding areas, landscaping, building occupants, pedestrians, vehicles and non-masonry surfaces during the work from contact with chemical restoration cleaners and paint strippers, residues, rinse water, fumes, wastes, and cleaning effluents. H. Surface Preparation: Describe surface preparation to be completed before application of restoration cleaners and paint strippers. I. Application: Describe application procedures of restoration cleaners and paint strippers. 1.010 Protection A. All materials shall be carefully handled in transit and on the site so as to keep units whole, edges sharp and faces clean and undamaged. Masonry units shall not be dumped out, but shall be delivered in pallets, handles individually or in suitable groups and properly stacked. B. Masonry units of all types shall be protected from wetting by rain or snow and shall be kept covered when not in use. MSBA Accelerated Repair Program RK Finn/Ryan Road and Leeds Elementary Schools Northampton, Massachusetts 04 01 20 - 5 C. Manufactured materials such as cleaning agents, mortar mix, cement and lime shall be delivered and stored in their original containers, plainly marked with product identification and manufacturer's name. D. Materials in broken containers or in packages showing watermarks or other evidence of damage shall not be incorporated into the Work and shall be removed from the site. E. Store unopened cartons of glass block in a clean, cool, dry area. F. Protect opened cartons of glass block against windblown rain or water run-off with tarpaulins or plastic covering. G. Project/Site Conditions: Do not install glass block / masonry brick units when temperature is 40°F (4°C) and falling. Maintain the temperature of glass unit masonry / masonry brick units above 40°F (4°C) for the first 48 hours after construction. 1.11 Environmental Requirements A. Do not repoint, coat, caulk, clean, wash down or wet surfaces, or waterproof when temperature may drop below 40 degrees F within 24 hours. Follow cold weather procedures as set out in ASNI A41.1 when temperatures may drop below 40 degrees F. B. For work not listed above, follow manufacturers recommendations for environmental requirements. 1.12 Scaffolding, Limited Access Zone, Bracing and Equipment A. Furnish, install and maintain as long as is necessary, removing when no longer needed safe and adequate staging, scaffolding, hoisting, centering and other equipment necessary for the proper execution of the Work specified and indicated. B. Safety requirements for masonry wall construction are to be coordinated with the General Contractor and include the following: 1. A limited access zone shall be established whenever a masonry wall is being constructed. The limited access zone shall conform to the following: a. The limited access zone shall be established prior to the start of construction of the wall. b. The limited access zone shall be equal to the height of the wall to be constructed plus four feet and shall run the entire length of the wall. c. The limited access zone shall be established on the side of the wall which will be unscaffolded. d. The limited access zone shall be restricted to entry by employees actively engaged in constructing the wall. No other employees shall be permitted to enter the zone. e. The limited access zone shall remain in place until the wall is adequately supported to prevent overturning and to prevent collapse unless the height of the wall is over eight feet, in which case the limited access zone shall remain in place until the requirements of paragraph (b) of this Section have been met. MSBA Accelerated Repair Program RK Finn/Ryan Road and Leeds Elementary Schools Northampton, Massachusetts 04 01 20 - 6 f. All masonry walls over 8 feet in height shall be adequately braced to prevent overturning and to prevent collapse unless the wall is adequately supported so that it will not overturn or collapse. The bracing shall remain in place until permanent supporting elements of the structure are in place. C. Staging and scaffolding shall comply with all applicable legal codes and regulations, including the Williams-Steiger Occupational Safety and Health Act of 1970 (OSHA). 1.12 Warranty A. Provide a 5-year manufacturer’s warranty on Glass Block units, including labor and materials for repair and replacement. B. This Contractor further states that he will, at his own expense, repair and replace all such defective materials or workmanship and all other Work damaged thereby which is so damaged during the two (2) year warranty period. PART 2 - MATERIALS 2.01 Masonry Materials A. All materials not specified by trade name shall meet the approval of the Architect. B. Materials shall be stored and handles so as to prevent damage and deterioration. Manufactured materials such as cement and lime shall be delivered and stored in the original containers and those showing evidence of damage shall be wholly rejected. C. Portland cement shall conform to ASTM-C-150, current specifications, Type 1. D. Hydrated lime shall be high calcium type conforming to ASTM C-207, current specifications, Type S. 2.02 Brick Units A. Face bricks for repairs shall match adjacent units as nearly as possible as approved by the Architect. Face brick shall be Brick shall be modular size, conforming to ASTM C216, Type SW, Grade FBS Acceptable manufacturers are: 1. Stiles and Hart Brick Company, Bridgewater, MA 2. Morin Brick company, Auburn, ME 3. Glen Gary Brick, Bigler, PA 2.03 Glass Unit Masonry A. Solid glass units, nominally 8 inch x 8 inch x 4 inch thick made of clear colorless glass with a polyvinyl butyral edge coating. Pattern type: VISTABRIK® Solid Glass Block. NOTE: Provide a polyvinyl butyral edge coating for better bonding and to provide for an expansion/contraction mechanism for each block. Acceptable manufacturers are: 1. Pittsburgh Corning Corporation, Pittsburgh, PA 2. Medina Glass Block Inc. MSBA Accelerated Repair Program RK Finn/Ryan Road and Leeds Elementary Schools Northampton, Massachusetts 04 01 20 - 7 3. Glass Block of America, Inc. 2.04 Masonry Filler Materials A. Filler for top joint of interior non-bearing masonry partitions, at control joints and where otherwise indicated or required shall be non-combustible compressible filler, 3/8 inch thick and in widths required to fill joints to a point 3/8 inch from each face of walls. 2.05 Glass Unit Masonry Reinforcement A. Panel Reinforcing: two parallel 9 gauge wires either 15/8 inch or 2 inch on center with electrically butt-welded crosswires spaced at regular intervals, Type 304 stainless steel. B. Panel Anchors: 22 gauge by 16 inches long by 1¾ inches wide of Type 304 stainless steel. C. Expansion Strips: made of polyethylene foam with a thickness of 3/8 inch. D. Joint Reinforcing Placement for Masonry Units: Reinforcing shall be placed at all masonry unit walls. In general, place reinforcing every 16 inch on centers every other block course laid continuous. Use 6 inch laps for continuity. Reinforcement shall be placed in first and second bed joints above openings and in every second block course thereafter and throughout partitions. Extend reinforcing onto intersecting partitions to sufficient depth for proper bond. Provide performed corners and "tee" pieces at all intersections and corners. Comply with drawings when more stringent requirements are indicated. 2.06 Reinforcing Bars A. Type: Where indicated on the Drawings and where required, reinforcing bars used at masonry reinforcing wall conditions shall conform to ASTM A-615, Grade 60, including all applicable requirements set forth under Section 03300, Concrete. B. Placement: Refer to Drawings for spacing and sizes of reinforcing bars required at bearing and non-bearing masonry wall conditions including horizontal bar where required to top of masonry unit bond beam. Maintain 1 inch minimum clearance on all sides of reinforcing bars. Support and secure bars against displacement during grouting. Bars shall be a minimum of 4'-0" long except as otherwise indicated on the Drawings. Lapping at splices at horizontal applications and single lengths and where shown at vertical application shall be in accordance with published recommendations. 2.07 Masonry Ties: A. Brick Veneer Anchors and Ties: Pos-I-Tie by Heckmann Building Products, Chicago, IL or equal with the following characteristics: B. Veneer Anchors: Zinc alloy barrel, with flanged head and eye with corrosion resistant self- drilling threaded screws to cover fastener hole. Length of barrel shaft sized to suit depth of material penetrated, allowing shoulder to seat directly on back-up, with ¾ inch diameter washer under flanged head sealing surface penetration at anchor. 1. Screws for Brick Veneer to Steel Studs: Heckmann Self-Drilling Screw. 2. Screws for Brick Veneer to Concrete, CMU, Wood or Brick: Heckmann Tapcon. 3. Screws for Brick Veneer to Structural Steel: Heckmann Dril-It. MSBA Accelerated Repair Program RK Finn/Ryan Road and Leeds Elementary Schools Northampton, Massachusetts 04 01 20 - 8 a. Ties: 3/16 inch diameter, triangular shape, hot-dip galvanized wire ties, ASTM A 641 or ASTM A 82 with 1.30 ounces per square foot zinc coating conforming to ASTM A 153, Class B-3. Length as required for not less than 75% embedment in mortar joints. b. At stack bond areas and where heights of brick of other than running or flemish bond exceed 8 inches shall be Vee wall ties, minimum 3/16 inch diameter wire, 5 inch length for use with high strength anchor with continuous 9 GA galvanized wire extending a minimum of 1’-0” beyond stack bond joint. Finish shall be hot-dipped galvanized. c. In general, ties are to be spaced at 1’-4” horizontally and 1’-4” vertically. The minimum quantity is one (1) per two (2) square feet. d. Ties for new block walls to existing walls shall be continuous channels AHB 360 C with slots for #363 Gripstay Anchors. 2.08 Mortar and Grout A. Mortar 1. Glass Unit Masonry: Mortar: Limit cementitious materials in mortar to Portland Cement and lime. Type S in accordance with ASTM C270. Mortar shall be 1 part Portland Cement, ½ part lime, and sand equal to 2¼ to 3 times the amount of cementitious material (cement plus lime), all measured by volume. (For exterior glass block panels, an integral type waterproofer should be added to the mortar mix.) No antifreeze compounds or accelerators allowed. 2. Portland Cement: Type I in accordance with ASTM C150. If a waterproof Portland Cement is used, the integral type waterproofer shall be omitted. (Masonry Cement is not acceptable.) Color: White. 3. ___ Lime: Shall be a dolomitic pressure-hydrated lime, special hydrate, Type S, in accordance with ASTM C207. 4. Sand: A clean, white quartzite or silica type, essentially free of iron compounds, in accordance with ASTM C144, not less than 100% passing a No. 8 sieve. 5. Integral Type Water-repellent: Stearate type by The Euclid Chemical Company (Integral Waterpeller® Powder, Not Liquid, 1-800-321-7628), or approved equal. Note: Add Integral Waterpeller® powder to dry mortar mix. Do not add powder to wet mortar mix. 6. External Type Water Proofer: Water based silane sealer type by BASF Corporation (HYDROZO ENVIROSEALTM 40, 1-800-243-6739). Note: Remove excess sealer from glass surfaces soon after application. 7. Veneer Masonry: Type N Mortar – min. 28 day compressive strength: 750 PSI. 8. Grout: Fine Type - Min. 28 day compressive strength: 2500 PSI. 2.09 Mortar Materials MSBA Accelerated Repair Program RK Finn/Ryan Road and Leeds Elementary Schools Northampton, Massachusetts 04 01 20 - 9 A. Cement: Shall be an American Portland Cement, conforming to ASTM C-150, Type II for concrete masonry units as approved by the Architect B. Air Entraining Admixtures: For grout fill shall conform to C-260 C. Lime: Shall be plastic hydrate, conforming to ASTM C-207, Type S (Only) D. Sand: Clean, washed uniformly well graded, conforming to ASTM C144-542, 100% passing a No. 8 sieve with not more than 35% passing a No. 50 sieve, and with a fineness modulus maintained at 2.25 plus-or-minus 0.10, light in color, and obtained from a single source. E. Shrinkage control additive for parging mortar mix for individual brick replacement: Acrylic polymer modifier, specifically formulated for adding to mortar mixes, Rohm & Haas Acrylic Modifier; Sisibond Products, Inc. C-21; Boiardi Products, Inc. Elastiment 150; or equal. F. Integral waterproofing for exterior mortar mixes: Master Builders Omicron Mortarproofing, Sonneborn Hydrocide, Pardee Dycrete, or equal. G. Water: Shall be potable and free from injurious contaminants 2.10 Brick Mortar A. Brick mortar color and texture shall match existing as nearly as possible. Use varying sand colors to affect modification of the final mortar color, to the extent feasible as approved by the Architect. 2.11 Thru-Wall Flashing A. Thru-wall flashing shall be accomplished with two types: 1. A two piece assembly, including a self-adhering membrane flashing combined with a metal drip piece.Membrane flashing: Polygard Products Inc. 650 self-adhering rubberized asphalt membrane. This flashing is a "system" which includes prefabricated end dams and corners which are to be used throughout the installation. Metal Drip: 16 ounce lead coated copper with 1/4 inch drip. 2. One piece bent 22 gauge stainless steel sheet through-wall flashing with ¼ inch crimped drip edge. Fastened with stainless steel fasteners Stainless Steel Type 302 or 304 to glass unit masonry backup wall in continuous bed of sealant and membrane flashing. 2.12 Sheet Copper A. All sheet copper shall be American made; manufacturer's trade name and weight of copper shall be marked on each sheet. Thickness shall match existing in areas of repair. 1. Copper: ASTM B 370; temper 0600 is required for forming; 16 oz. (0.0216 inch thick) except as otherwise indicated. 2. Provide lead coating of 0.06 lbs per sq. ft. on exposed copper surfaces. 2.13 Counter Flashing - Counter Flashing shall be 2-piece 16 ounce copper reglet flashing as manufactured by Fry Reglet company or approved equal. MSBA Accelerated Repair Program RK Finn/Ryan Road and Leeds Elementary Schools Northampton, Massachusetts 04 01 20 - 10 A. Air Barrier Tape: CCW-705 Air Barrier Tape by Carlisle Coatings and Waterproofing or equal. B. Adhesive for Bonding Insulation at Vertical Surfaces: Product recommended by insulation manufacturer with demonstrated capability to bond insulation securely to substrates indicated without damaging insulation or substrates. 2.14 Cavity Wall Drainage Mat and Weep Vents A. Drainage mat shall be a polyethylene or nylon mesh in trapezoidal configuration, 10 inches high, thickness equal to cavity width, as manufactured by Mortar Net U.S.A. Ltd. B. Weep vents shall be synthetic fiber bonded with flame-retardant adhesive with 90% open mesh, as manufactured by Mortar Net or approved equal. 2.15 Existing Masonry Surfaces A. Materials used to repair or patch existing masonry surfaces shall match as nearly as possible the existing masonry surfaces being patched in color, size and texture, subject to the approval of the Architect. 2.16 Restoration Cleaners A. Manufacturer: ProSoCo Inc., Kansas City, Kansas. B. Restoration Cleaner: "Sure Klean Restoration Cleaner" General purpose acidic restoration cleaner for brick, terra cotta, sandstone, granite, and many other masonry surfaces. Dissolves heavy atmospheric soiling. Not suitable for limestone, marble, travertine, concrete, or cast stone surfaces. 1. Form: Clear liquid 2. Color: Light Amber 3. pH: 1.2 4. Specific Gravity: 1.05 5. Flash Point: None C. Heavy Duty Restoration Cleaner: "Sure Klean Heavy Duty Restoration Cleaner" concentrated, general purpose acidic restoration cleaner for brick, terra cotta, sandstone, granite and many other masonry surfaces. Dissolves heavy atmospheric soiling. Not suitable for limestone, marble, travertine, concrete or cast stone surfaces. i. Form: Clear liquid ii. Color: Light amber iii. pH 1:3 Dilution: 1.5 iv. Specific Gravity: 1.13 v. Flash Point: None 1. Limestone and Masonry Prewash: "Sure Klean 766 Limestone & Masonry Prewash: Non-acidic alkaline gel for dissolving heavy carbon soiling from masonry surfaces. General purpose cleaner for very dirty surfaces. Spot cleaner for beneath window sills or on other heavily stained areas. Safe for most unpolished limestone, marble, travertine, concrete, and cast stone surfaces. Effective on heavily soiled brick, terra cotta, sandstone, granite and most other masonry. Neutralize treated surfaces with "Sure Klean Limestone & Masonry Afterwash: or "Sure Klean Restoration Cleaner". vi. Form: Gel vii. Color: Translucent viii. pH: 14 MSBA Accelerated Repair Program RK Finn/Ryan Road and Leeds Elementary Schools Northampton, Massachusetts 04 01 20 - 11 ix. Specific Gravity: 1.27 x. Flash Point: None 2. Limestone and Masonry Afterwash: "Sure Klean Limestone & Masonry Afterwash: Mild, acidic afterwash to neutralize surfaces prewashed with alkaline, "Sure Klean 766 Limestone & Masonry Prewash:, "Sure Klean Heavy Duty Paint Stripper:, and "Sure Klean 1217 Heavy Carbon Poultice". Removes cleaning residues and restores masonry to its natural appearance. i. Form: Liquid ii. Color: Clear iii. pH: 1.6 iv. Specific Gravity: 1.02 v. Flash Point: > 200 degrees F. 3. Strippable Masking: "Sure Klean Strippable Masking: Protects most non-porous surfaces such as glass, unpainted metal, and polished stone from cleaning chemicals and residues by forming a temporary protective coating. Do not use on synthetic finishes, window gaskets, caulks, sealants, acrylic or polycarbonate sheeting, reflective films, plastic, wood, porous metal, porous masonry paint and all solvent-sensitive surfaces. i. Form: Thick liquid. ii. Color: White iii. pH: None iv. Specific Gravity: 0.95 v. Flash Point: 20 degrees F. 4. Asphalt and Tar Remover: "Sure Klean Asphalt & Tar Remover". Removes asphalt, tar, grease and hydraulic and motor oil stains from brick, stone, concrete and other masonry surfaces. Removes many clear sealers, caulk residues, and light paint spatters from masonry. Do no use on synthetic finishes, window gaskets, caulks, sealants, acrylic or polycarbonate sheeting, reflective films, plastic, wood, porous metal, porous masonry, paint, and all solvent sensitive surfaces. i. Form: Liquid ii. Color: Clear iii. pH: None iv. Specific Gravity: 0.961 v. Flash Point: 79 degrees F. D. Paint Strippers 1. Heavy Duty Alkaline Paint Stripper: "Sure Klean Heavy Duty Paint Stripper". Solvent-alkaline gel for removal of multiple layers of paint and graffiti from porous masonry surfaces. Highly effective on variety of paint types. Remains active for up to 24 hours. Neutralize treated surfaces with "Sure Klean Limestone & Masonry Afterwash" or "Sure Klean Restoration Cleaner". Do not use on polished marble or aluminum surfaces. May damage or raise grain on wood surfaces. 2. Standard Grade i. Form: Gel ii. Color: Light Brown iii. pH: 14 iv. Specific Gravity: 1.27 v. Flash Point: > 175 degrees F. MSBA Accelerated Repair Program RK Finn/Ryan Road and Leeds Elementary Schools Northampton, Massachusetts 04 01 20 - 12 3. Spray Grade i. Form: Loose paste. ii. Color: Brown iii. pH: 14 iv. Specific Gravity: 1.39 v. Flash Point: 138 degrees F. 4. Solvent Paint Stripper: "Sure Klean Fast Acting Paint Stripper". Solvent gel for removal of high strength paints and coatings such as epoxy, polyurethanes, and floor enamels from masonry, wood, and metal surfaces. Removes may types of graffiti. Do not use on synthetic finishes, acrylic or polycarbonate sheeting, reflective films, plastic, and all solvent-sensitive surfaces. i. Form: Gel ii. Color: Translucent iii. pH: None iv. Specific Gravity v. Flash Point: 95 degrees F. E. Caulking 1. Products i. Exterior caulking material shall be a one-part, low modulus, moisture curing, modified polyurethane joint sealant: Sikaflex - 15 LM. The product shall tolerate +100 percent and -50 percent movement. 2. Caulking Primers i. Caulking primers shall be used and shall be liquid type recommended by the manufacturer of the products used for the particular surfaces being caulked. 3. Joint Backing i. Closed cell polyethylene foam or neoprene rod. Rod size to allow for 25% compression when inserted into the joint. Where joints are too shallow to allow for the use of a backer rod, or are right angle joints, a bond breaker tape must be used as "481 Tape" manufactured by "3M" or approved equal. The material shall be compatible with the caulking to be used. If proper joint backing is not used, the work will be rejected. F. Masonry Joint Reinforcement 1. Composite and Single Wythe Types: Longitudinal reinforcement shall be standard, ladur, as manufactured by AA Wire Products, Hohmann and Barnard, Inc., or "Fur-O-Wall", fabricated of cold-drawn, mild-galvanized 9-gauge steel wire conforming to ASTM A-82, with two (2) deformed longitudinal rods welded at 16 inch intervals in the same place to a continuous perpendicular cross rod. 2. Widths: Except as otherwise noted on the Drawings, all longitudinal reinforcement shall be of such width as to place the longitudinal rods within 1 inch of each face of wall or partitions. MSBA Accelerated Repair Program RK Finn/Ryan Road and Leeds Elementary Schools Northampton, Massachusetts 04 01 20 - 13 3. Joint Reinforcing Placement for Masonry Units: Reinforcing shall be placed at all masonry unit walls. In general, place reinforcing every 16 inch on centers laid continuous. Use 6 inch laps for continuity. Provide preformed corners and "tee" pieces at all intersections and corners. G. Reinforcing Bars 1. Type: Where indicated on the Drawings and where required, reinforcing bars used at masonry reinforcing wall conditions shall conform to ASTM A-615, Grade 60, including all applicable requirements set forth under Section 03000, concrete. Provide epoxy coating where indicated. 2. Placement: Refer to Drawings for spacing and sizes of reinforcing bars required. Support and secure bars against displacement during grouting. Bars shall be a minimum of 4'-0" long except as otherwise indicated on the Drawings. 3. Adjustable Wall Ties: For brick veneer walls, ties shall be eye and pintle type rectangular ties. Overall tie size shall be 9-1/2 inches. The ties shall be manufactured by Heckmann Building Products or equal type by AA Wire Products Company, Hohmann and Barnard, Inc., as approved by the Architect. Provide one (1) wall tie per every two (2) square feet of wall area. Ties shall be hot-dipped galvanized. H. Mortar Materials 1. Cement: Shall be an American Portland Cement, conforming to ASTM C- 150, Type II for concrete masonry units as approved by the Architect. 2. Air Entraining Admixtures: For grout fill shall conform to C-260 3. Lime: Shall be plastic hydrate, conforming to ASTM C-207, Type S (Only) 4. Sand for Masonry Units and Brick: shall be clean, washed, uniformly well- graded masonry sand conforming to the requirements of ASTM C-144 5. Aggregate for Grouting: At bearing walls and for anchoring embedded items shall be ASTM C-404 6. Water: Shall be potable and free from injurious contaminants. 2.17 Membrane Flashing A. Masonry thru-wall flashing shall be coated 3 ounce copper equal to Phoenix Building Products Co., "Cop-R-Flash" Type A, AFCO Products Co., "Copper-Fabric", or York Mfg. Co "Cop-R-Tex". 2.18 Coating for Reinforcing Steel A. Corrosion protection for all steel reinforcing exposed during cast stone restoration shall be Sika Armatec 110 CPO CEM as manufactured by Sika Corp. This is a two component, factory proportioned mix. 2.19 Epoxy Repair Gel MSBA Accelerated Repair Program RK Finn/Ryan Road and Leeds Elementary Schools Northampton, Massachusetts 04 01 20 - 14 A. Epoxy: Sikadur Injection Gel PART 3 - EXECUTION 3.01 Masonry A. All masonry shall be laid with and shall be reinforced and tied as detailed and in accord with the recommendations of the applicable trade publications. Bond and coursing shall match existing. B. Installation of through wall flashing in existing masonry walls shall be done in increments / sections as not affect the structural integrity of the existing masonry wall. The contractor shall submit for approval procedures for the installation of the through wall flashings including all bracing and shoring required to do the work prior to commencement of work. 3.02 Mixing Proportions A. Mixing: Mortars shall be machine-mixed in an approved type of mixer in which the quantity of water can be accurately and uniformly controlled. Where hydrated limes are used for mortars requiring a lime content, use the dry mix method. Where the dry mix method is employed, the materials for each batch shall be well raked and turned over together before the water is added until the even color of the mixed materials indicates that the cementitious materials have been thoroughly distributed throughout the mass, after which the water shall be gradually added until a thoroughly mixed mortar of the required plasticity is obtained. The same mortar mixture shall be used throughout. B. The method of measuring materials shall be such that the specified proportions of the materials can be controlled and accurately maintained. Shovel measurement will not be allowed. C. All cementitious materials and aggregate shall be mixed for a least three (3) minutes in a mechanical batch mixer with the maximum amount of water to produce a workable consistency. Hand mixing shall not be used unless approved. D. Mortar which has begun to set or is not used within 2-1/2 hours after initial mixing shall be discarded. Mortar which has stiffened due to evaporation within the 2-1/2 hour period shall be retempered to restore its workability. Retempering mortar which has partially hardened without additional cement aggregate or water will not be permitted. 3.03 Workmanship A. All masonry shall be laid by skilled workers under adequate supervision, shall be laid plumb, true to lines and levels with joints of uniform thickness (unless otherwise noted), all surfaces true and corner straight and plumb. B. The Masonry Subcontractor shall examine all Drawings as to requirements for accomodations and/or installation of work of other trades and shall provide all required recesses, chases, slots, cutouts, and built-ins for such work and shall also be responsible for the accommodations and/or installations of bearing plates, setting plates, setting of loose lintels, placement of anchors, bolts, reinforcing bars, and other items occurring in the masonry work. Every precaution should be taken to minimize future cutting and patching. MSBA Accelerated Repair Program RK Finn/Ryan Road and Leeds Elementary Schools Northampton, Massachusetts 04 01 20 - 15 C. No masonry shall be erected when the ambient temperature is below 40 degrees F. on a falling temperature or when there is a probability of freezing conditions existing within forty- eight (48) hours, unless directed or approved by the Architect. D. No frozen work shall be built upon and no brick or other unit having a film of water or frost on its surfaces shall be laid. E. Measurements: Proportions shall be by volume. One (1) bag of Portland cement (94 pounds) shall be considered as one (1) cubic foot; one (1) bag of lime (50 pounds) as 1 1/4 cubic foot; and sand shall be measured in dry condition (80 pounds being equal to one (1) cubic foot). F. Mortars shall be as follows: 1. Match color and texture of existing mortar. Refer to paragraphs on repointing. 2. Conduct tests using the ingredients specified and make recommendations as to mix that will produce the most satisfactory results depending on the conditions prevailing at the time of mixing proportions. G. Mortar Strengths: Mortar for units except reinforced masonry units shall possess a strength of Type S mortar when tested in cubes or cylinders at the end of a 28-day aging period, all in accordance with ASTM C-270. Reinforced masonry unit mortar shall possess strength of 2500 psi in 28 days, in accordance with ASTM C-476, Type PM or PL. H. Anti-freeze admixtures will not be allowed to be in the mortar. I. Bond shall be kept plumb throughout. Units with greater than 12% absorption shall be wetted (except in freezing weather) before laying, as necessary to prevent too rapid an absorption of the water from the mortar and to ensure maximum bond. Work and items to be built in the masonry shall be built in as the work progresses and the space around built-in items shall be filled solidly wit masonry and mortar. Chases and pockets shall be built-in as shown on the drawings and shall be kept free from mortar and other debris. All masonry partitions shall extend to underside of the deck or structure above, except as otherside detailed. J. Unfinished work shall be stepped back for jointing with new work. Before new work is started, all loose mortar shall be removed and the exposed joint thoroughly wetted not less than twelve (12) hours before laying new work. K. Before stopping work each day, the Masonry Subcontractor shall cover the tops of all unfinished walls with waterproof reinforced paper which shall be properly secured in place and weighted down, and shall turn down not less that 4 inches on each side. Coverings shall be kept in place at all times except when men are working on the walls. L. Whenever any concrete or mortar is hoisted up the sides of walls or transported across floor slabs, the surface of same shall be protected and covered with a waterproof canvas tarpaulin or reinforced paper. M. Where adjustments must be made after the mortar has started to set, the masonry unit shall be removed and the mortar in the joint replaced with fresh mortar. N. All work shall be kept as clean as possible so that cleaning down may be accomplished easily; protect all masonry from stain at all times to guard from discoloration. Splashing at MSBA Accelerated Repair Program RK Finn/Ryan Road and Leeds Elementary Schools Northampton, Massachusetts 04 01 20 - 16 staging levels shall be avoided either by covering the courses at these levels or by cleaning the face brick and units so spattered while the mortar is still fresh. O. All exposed edges of brick and block shall produce a true, smooth, even plane. Irregular cutting of brick shall not be permitted and will be rejected. 3.04 Brick Laying A. Brick Coursing: Brick coursing shall be laid to match existing coursing. B. Bond: Shall match existing. C. Jointing: All joints on the exposed face of brick walls and base shall be tooled to match existing joints. This shall be done with a stainless steel tool, before the mortar hardens but not until thumbprint hard, and with sufficient force to press the mortar tightly against the brick on both sides of the joint. Great care shall be taken not to spread the mortar over the edges of the face brick. All joints shall be uniform thickness throughout. D. Brick shall be laid with shoved joints and all joints shall be completely and thoroughly filled with mortar; bedding and buttering shall not be used; furrowed beds will not be permitted. E. All brickwork shall be laid level and plumb. Brickwork shall be done from staging so that the mason may readily fill all joints. No overhead laying will be permitted. F. Set all anchors, ties, inserts, and bolts required in the Work shown or specified hereinbefore. G. Rake all joints to adequate depth where required to receive caulking and sealant. H. Extend flashing beyond jambs of openings and turn up to form a pan. Apply mastic to lintels and at joints in flashing. Extend flashing beyond outside face of brick and turn down to form a drip. Extend flashing up a minimum of 8 inches at new lintels. 3.05 Cast Stone Cleaning A. Determination of actual material and concentrations shall be determined according to testing as approved by the Architect. Use of all materials shall be in strict accordance with manufacturer's recommendations. 1. Fast Acting Paint Stripper a. Testing: Test each type of surface and each material to be stripped. Testing should determine the best dwell time and number of applications necessary for complete stripping. Test panels also determine the effects of the stripper and pressure rinse on older, more delicate surfaces. Some surfaces require restricting water pressure to 150-500 psi or hand rinsing. Test areas should be allowed to thoroughly dry (three to seven days for masonry and porous surfaces) to disclose final appearance and results. Make the test panel available for inspection and approval before proceeding with overall cleaning. b. Application (1) Prepare the surface by dry scraping or high pressure rinsing to remove all peeing and loose paint. MSBA Accelerated Repair Program RK Finn/Ryan Road and Leeds Elementary Schools Northampton, Massachusetts 04 01 20 - 17 (2) Using a solvent resistant brush or roller, apply a uniformly thick coating of Fact Acting Paint Stripper to the dry surface. (3) Allow stripper to dwell on the surface for 15-20 minutes or until paint "lifts" or shows indications of dissolving. Periodic agitation with a stiff bristle brush will improve stripper penetration. Take precautions to prevent passerby from coming near treated surfaces. NOTE: Stripper should not be allowed to dry on the surface - stripping results may be unsatisfactory. If tests indicate long waiting periods will be necessary, reapply the stripper to prevent the previously applied material from drying. (4) Recommended method for removing Fast Acting Paint Stripper and paint residue is with high pressure water rinsing equipment fitted with a minimum 25 fan tip. Equipment providing 400 to 1200 psi at a flow rate of four to six gallons of water per minute is generally found to be most effective. heated water (150-180 degrees F) may improve stripping efficiency. 2. Heavy Duty Paint Stripper a. Testing: Apply separate test panels. The first panel should dwell 1 to 2 hours, the second 4 to 6 hours and the third 12 hours or overnight. After all panels have been pressure rinsed, evaluate results and determine optimum dwell time. b. Application: (1) Remove all loose and peeling paint using pressure water or scraper. Surface should be thoroughly dry before applying paint stripper. (2) Apply a heavy coat of stripper to produce a buildup of approximately 1/8 inch. (3) Allow paint stripper to remain on the surface until the paint is obviously "lifted" or dissolved. If stripper is left on the surface unattended, take precautions to prevent pedestrians from coming near treated surfaces. (4) Using pressure rinsing equipment, thoroughly rinse the stripper and solubilized paint from the surface. Use as much water as possible. (5) Reapply stripper as required. Shorter dwell times are frequently adequate on second applications where only small amounts of paint remain. (6) When all paint has bee removed, use the appropriate Sure Klean restorative cleaner to neutralize the surface, remove all trades of stripper, and "pigment shadow:. Use Sure Klean Restoration Cleaner for brick, terra cotta, sandstone and other siliceous type masonry. Use Sure Klean Limestone Afterwash for limestone, concrete, cast stone and other calcareous type masonry. (7) Allow to dry thoroughly prior to repainting. MSBA Accelerated Repair Program RK Finn/Ryan Road and Leeds Elementary Schools Northampton, Massachusetts 04 01 20 - 18 3. Heavy Duty Concrete Cleaner a. Testing (1) Test each type of masonry (and each type of strain). Allow to dry 3- 7 days before inspection. clean test areas according to the application procedure below. Make the test panel available for inspection and approval by the Architect. b. Application (1) Pre-wet a large area. When cleaning highly porous surfaces on hot days, a second pre-wetting is suggested. When cleaning vertical walls, keep lower areas wet to avoid streaks. (2) Apply cleaning solution freely, suing a soft fibered masonry washing brush or low pressure (40psi) spry. Allow it to remain on the wall for 1- 2 minutes depending on drying conditions. Do not allow cleaning solution to dry into the surface, because this may leave residue and stain. (3) Reapply cleaning solution and scrub or scrape surface as required using wood blocks or other non-metallic scraping devices. Take care not to harm the surface. (4) Rinse thoroughly with fresh water, complete rinsing is important to assure removal of all residues from the porous masonry. High Pressure rinsing equipment with pressures of 500-1500 psi at a volume of 6-10 gallons per minute will prove most effective. 3.06 Brick Cleaning A. Use of all materials shall be in strict accordance with manufacturer's recommendations. 1. 766 Masonry Prewash a. Testing (1) Clean a test panel before beginning overall cleaning operations to determine the effective ness of the cleaning compound, for the most efficient cleaning. Test each type of masonry surface and choose test areas that are representative of stain conditions on the entire project. (2) 766 Masonry Prewash should be used in concentrate during initial testing. If test panels using concentrated material cleaned effectively, additional tests may be run using a solution of 766 Masonry Prewash diluted with up to three parts water to one part concentrate. b. Application (1) Protect all surrounding non-masonry surfaces. (2) Prewet a large area of masonry to be cleaned. (3) Apply a heavy coating of 766 Masonry Prewash to the surface using a brush or roller. MSBA Accelerated Repair Program RK Finn/Ryan Road and Leeds Elementary Schools Northampton, Massachusetts 04 01 20 - 19 (4) Allow the material to remain on the surface for 30 minutes to 1 hours. Under normal weather conditions (71 degrees F/40% humidity) one hour is long enough standing time to clean the dirtiest masonry surface. (5) Pressure rinse making sure to hit each portion of the masonry surface with concentrated water pressure. If high pressure water equipment is not available, reapply 766 Masonry Prewash and scrub vigourously with stiff bristled brush or scrubbing pad. Rinse thoroughly with fresh water. (6) Immediately apply a solution of the appropriate Sure Klean Restoration Cleaner as per the instructions on the product label. 2. Restoration Cleaner and Heavy Duty Restoration Cleaner. a. Testing: Test panels prior to beginning full scale cleaning operations to determine the effectiveness of the cleaning procedures. Conduct tests on each type of masonry surface and be available for inspection and approval by the Architect. b. Application (1) Protect all surrounding window glass, aluminum, painted surfaces, and foliage with polyethylene or other proven protective material. Beware of wind protective material. Beware of wind drift onto auto and pedestrian traffic. (2) Prewet the surface to be cleaned with clean water. (3) Apply the cleaning solution liberally to the masonry surface using low pressure (50 psi), roller or brush. (4) Allow the cleaning solution to remain on the surface for 3 to 5 minutes. Reapply. Light scrubbing of the surface will improve cleaning results especially where high pressure rinsing equipment is not available. (5) Rinse the treated area thoroughly using high pressure rising equipment or garden hose with nozzle adjusted to provide a concentrated stream of water. Rinse from the bottom of the treated area to the top covering each section of the surface with a concentrated stream of water. 3.07 Cleaning Precautions A. Precautionary Measures 1. Use the adequate ventilation. Wash thoroughly after handling. Wear rubber gloves, face shields, goggles and protective clothing to avoid splash to bare skin or eyes and NIOSH/MSHA approved respirators for use with acids. 2. Avoid exposing building occupants to fumes. When applying outside occupied buildings, all windows, air intakes and exterior air conditioning vents should be covered (and air handling equipment shout down) during and for 30 minutes following application. Dispose of all empty containers according to federal, state and local regulations. B. Window / Door / Misc Material Protection MSBA Accelerated Repair Program RK Finn/Ryan Road and Leeds Elementary Schools Northampton, Massachusetts 04 01 20 - 20 1. Protect window frames using polyethylene secured by duct tape. Do not use making tape. 2. When applying stripper around protected frames, carefully brush apply to avoid contacting the protected frame surfaces. 3. Any accidental spill, drip, or splash must be cleaned off protected frames immediately to ensure that stripper does not contact frame surfaces. 4. Do not remove window frame protection until all stripping and rinsing is complete. If protection comes loose, it must be secured before work can proceed. C. Application 1. Test each surface and/or material to be treated to insure compatibility and desired water repellency results. The surface to be treated must be clean and free of all foreign matter and dry as possible to insure penetration of the water repellent. 2. Apply material as supplied do not dilute or alter material as packaged. Preferred method of application is with low pressure, airless diaphragm-type spray equipment or with a heavily saturated roller or brush. Equipment can be cleaned with commercial solvents. 3. Apply sealer in a "wet on wet" application. In the case of extremely dense surfaces, it may be necessary to restrict the amount of material applied to one saturating application to prevent surface darkening. 4. Apply sealer in a flooding application from the bottom up with sufficient material applied to produce a 6 to 8 inch rundown below the contact point of the spray pattern with the masonry surface. Allow the first application to penetrate the surface (approximately three to five minutes) and reapply in the same saturating matter. Less material will be required to saturate the surface on the second application. Note: When using brush or roller, care should be taken to assure that enough solution is applied. Applied sufficient material to thoroughly saturate the surface, making sure to brush out heavy runs or drips that do not penetrate. 3.08 Caulking Application A. Install appropriate joint backing and prime surfaces. B. Cauking shall be done neatly and all joints shall be tooled to compress the material into the joint and present a neat appearing finished joint. All material shall be in the joints. Depth of joints shall conform to manufacturers recommendations or will be rejected. C. Schedule: Caulking shall be provided in the following locations: 1. At all cast stone joints including perimeter joints adjacent to brick work. Cut-out existing mortar prior to installing caulking. 2. All other locations, where so noted on the drawings or where the use of caulking materials may be reasonable inferred as necessary to make the work of this section complete throughout the building. MSBA Accelerated Repair Program RK Finn/Ryan Road and Leeds Elementary Schools Northampton, Massachusetts 04 01 20 - 21 D. All mixing and application methods, times and weather shall be in strict accordance with the manufacturer's published recommendations. E. Adjacent surfaces shall be masked and all masonry shall be primed with a primer approved by the manufacturer of the caulking material. All joint shall be provided with a backer strip of the proper size to be compressed in the joint, leaving a space for caulking of the depth recommended by the manufacturer of the caulking material for the conditions. 3.09 Cast Stone Repair Mortar A. Surface Preparation 1. All loose concrete shall be tested by tapping with a hammer. Any loose material shall be removed with a chipping gun down to sound stone. 2. The surface must be mechanically prepared. Areas to be patched must be clean and sound. All loose and deteriorated concrete shall be removed by mechanical means approved by the Architect. Chip concrete substrate to obtain an aggregate profile of +/- 1/16 in. Be sure the area to be patched is not less than 1/8 in. in depth. Reinforcing steel must be mechanically cleaned and be free of rust, grease, oil, and other bond inhibiting matter. This can be accomplished by sandblasting or other methods approved. If half the diameter of the reinforcing steel is exposed, chip out behind the rebar. The distance chipped behind the rebar will be equal to or exceed the minimum placement depth of the polymer-modified portland cement mortar. 3. Cracks in the substrate in the area of the patching or overlay work must be treated as directed by the Architect. B. Application 1. Mixing the polymer-modified portland cement corrosion inhibiting reinforcing steel coating: Mix mechanically for three minutes with a low-speed (400-600 rpm) drill and jiffy paddle. Place approximately 1/2 of Component A into a clean dry mixing container. While mixing, slowly add all of Component A and continue to mix until a uniform past, with no lumps is achieved. Care should be taken to scrape down the sides of the mixing container at this time. Add the remainder of Component A and continue to mix until uniformly blended. 2. Mixing of the polymer-modified portland cement mortar: Mix manually or mechanically. Manually mix in a wheel barrow or mortar box. Mechanically mix in appropriate sized mortar mixer or with jiffy paddle and low-speed (400-600 rpm drill. Pour approximately 4/5 gal Component A into the mixing container. Add Component B while continuing to mix. Mix to a uniform consistency for a maximum of three minutes. Add remaining Component A to mix if a more loose consistency is desired. If manual mixing takes more than three minutes, mix smaller quantities. Should smaller quantities be needed, be sure the components are dosed in the correct ration and that the Component B is uniformly pre-mixed before batching. 3. Mixing of the polymer-modified portland cement concrete; Pour all, 1 gal., of Component A into the mixing container. Add Component B while continuing to mix. Add correct amount of the pre-approved coarse aggregate, 42 lb./unit maximum, and continue mixing to a uniform consistency. Mixing time should be three minutes maximum. 4. Placement Procedure: MSBA Accelerated Repair Program RK Finn/Ryan Road and Leeds Elementary Schools Northampton, Massachusetts 04 01 20 - 22 a. Polymer-modified portland cement corrosion inhibiting reinforcing steel coating: At the time of application, the surrounding concrete should be saturated surface dry with not standing water. Using a quality brush, coat the prepared reinforcing steel, making sure that all the exposed steel has been coated. Minimum application thickness is 40 mils for corrosion protection. Coating may be applied in single or multiple coats to achieve the 40 mils. Overlapping onto the concrete is expected. Allow coating to dry before applying the polymer-modified portland cement mortar/concrete, approximately 2-3 hours at 73F. If the polymer modified portland cement mortar/concrete is not to be placed as soon as the cure of the reinforcing steel coating allows, protect the coated steel from weather until such time as the repair is completed. b. Polymer-modified portland cement mortar/concrete: At the time of application, the substrate should be saturated surface dry with no standing water. Mortar and/or concrete must be scrubbed into substrate filing all pores and voids. While the scrub coat is still plastic, force material against edge of repair, working toward center. After filing, consolidate, then screed. Allow mortar to set to desired stiffness. Then finish with trowel, manual or power, for smoother surface. Broom or burlap drag rough surface. Areas where the depth of the repair area, to sound concrete, is 1 in. or less shall be repaired with polymer- modified portland cement mortar. In areas where the depth of the repair is greater than 1 in. the repair shall be made with polymer-modified portland cement concrete. c. Curing of the polymer-modified portland cement mortar/concrete is not required under most conditions. However, if ambient conditions might cause premature surface drying - high winds, high temperatures, direct sunlight, low humidity, etc. - use a fine mist of water, wet burlap, or non-solvent, water based curing compound, which as been pre-approved by the Engineer. d. Adhere to all limitations and cautions for the polymer-modified portland cement reinforcing steel coating can be cleaned from tools with water. The cured polymer-modified portland cement mortar and polymer-modified portland cement reinforcing steel coating can only be removed mechanically. C. Cleaning 1. The uncured polymer-modified portland cement mortar and polymer-modified portland cement reinforcing steel coating can be cleaned from tools with water. The cured polymer-modified portland cement mortar and polymer-modified. Portland cement reinforcing steel coating can only be removed mechanically. 2. Leave finished work and work area in a neat, clean condition without evidence of spillovers onto adjacent areas. 3.10 Repair Distressed Brickwork - All Areas A. All exterior masonry wall areas showing stress cracking, step fractures, areas where brick has drifted out of plumb or where brick has otherwise failed shall be cut out and rebuilt. When removing brick, sound headers should not be disturbed unless necessary. When rebuilding the brickwork, new work shall be laid plumb. New brick shall match existing as nearly as possible as approved by the Architect. Brick shall be clay, medium hard burned, solid and shall have a cold water absorption of from 4% to 10% but not more than 12%. MSBA Accelerated Repair Program RK Finn/Ryan Road and Leeds Elementary Schools Northampton, Massachusetts 04 01 20 - 23 They shall also match in size, color range and surface texture. All new brick work and repointing shall match existing as nearly as possible as approved by the Architect. B. All defective brick units shall be cut out and replaced with new. Defective brick are brick with cuts or breaks 1-1/2" or more in length, salmon bricks, spalled bricks, visually eroded bricks, or brick which have otherwise deteriorated so that water is not repelled. Replace all missing brick with new units. 1. Remove all existing metal hardware which has been abandoned. Replace the damaged brick. 3.11 Installation of Replacement Cast Stone Terra Cotta and Brick A. Remove each piece without touching the surrounding material. When the deteriorated stone or brick is chiselled out, care should be taken to avoid damaging the edges of the adjoining elements, particularly when removing the old mortar. B. The replacement unit can then be slid into the space left by the old. The fit of the new element should first be tested by fitting it into its space without mortar. A stone is placed on wedges of wet wood (or if it is a heavy block, or noncorrosive metal); the wedges are positioned so that they will be covered with at least 1-1/2 inches of mortar when pointing is completed. Any necessary corrections can be made at this stage. C. Cover the four sides of the space and the back face, with sufficient mortar so that there will be no air spaces left when the replacement element is pushed into place. Line up new cast stone and properly set up by tapping it with a wood or rubber mallet; if it enters to far, remove it and add more mortar in the space. With a large stone it may not be possible to rely on mortar to keep the new stone in place and it may be necessary to fit it in place with metal anchors. Lay a brick on a bed of mortar that matches the depth of the surrounding horizontal joints. After all the new elements have been installed and adjusted, repoint the joints to match the rest of the wall. Scrub the area clean with a brush and water to remove all excess mortar. 3.12 Epoxy Injection A. Comply with the manufacturers published recommendations for surface preparation, mixing, and application. 3.13 Final Cleaning A. All Work shall be kept as clean as possible so that cleaning down may be accomplished easily. Protect all masonry from stain at all times to guard from discoloration. Splashing at staging levels shall be avoided either by covering the courses at these levels or by cleaning the masonry so spattered while the mortar is still fresh. B. All masonry shall be thoroughly washed and cleaned with clear water and fiber brushed to remove mortar stains, dirt and dust. Defective joints shall be cut out of a depth of not less than 3/4 inch and properly repainted to match adjoining mortar. C. If difficulty is encountered removing stains from masonry using only water, this Subcontractor, if approved by the Architect, may use stiff fiber brushes and not over 1 5% solution of muriatic acid after he has demonstrated to the Architect that acid is necessary. MSBA Accelerated Repair Program RK Finn/Ryan Road and Leeds Elementary Schools Northampton, Massachusetts 04 01 20 - 24 D. Immediately after cleaning, the masonry surfaces shall be rinsed down with clear water. Allow the first application to penetrate the surface (approximately 3 to 5 minutes) and reapply in the same saturating manner. Less material will be required to saturate the surface on the second application. Note: When using brush or roller, care should be taken to assure that enough solution is applied. Apply sufficient material to thoroughly saturate the surface, making sure to brush out heavy runs or drips that do not penetrate. END OF SECTION