SECTION CONCRETE MASONRY UNITS PART 1 GENERAL 1.01 SUMMARY

Transcription

1 SECTION CONCRETE MASONRY UNITS PART 1 GENERAL 1.01 SUMMARY A. Section Pertains to Manufactured Concrete Masonry Units, including, but not limited to, Standard Concrete Masonry Units and Split-Face Concrete Masonry Units SECTION INCLUDES A. Manufactured Concrete Masonry Units; both load bearing and non-load bearing and intended for use in unit masonry assemblies PRODUCTS A. Manufactured Concrete Masonry Units RELATED SECTIONS A. Section Unit Masonry Assemblies 1.05 REFERENCES A. ASTM C33 -Standard Specifications for Concrete Aggregates B. ASTM C90 - Standard Specification for Load bearing Concrete Masonry Units. C. ASTM C129 - Standard Specification for Non-load bearing Concrete Masonry Units. D. ASTM C140 - Sampling and Testing Concrete Masonry Units and Related Units. E. ASTM C270 - Standard Specification for Mortar for Unit Masonry. F. ASTM C331 - Lightweight Aggregates for Concrete Masonry Units. G. ASTM C426 - Linear Drying Shrinkage of Concrete Masonry Units. H. ASTM C476 - Standard Specification for Grout for Masonry. I. ASTM C Terminology of Concrete Masonry Units and Related Units. J. ASTM C Terminology of Masonry. K. ASTM E514 - Water Penetration and Leakage Through Masonry. L. ACT /ASCE 5-95/TMS Building Code Requirements for Masonry Structures

2 M. ACI /ASCE 6-95/TMS Specification for Masonry Structures. N. National Concrete Masonry Association (NCMA) Concrete Masonry Shapes and Sizes Manual. 0. National Concrete Masonry Association (NCMA) TEK Manual for Concrete Masonry Design and Construction SUBMTTTALS 1.07 SAMPLES A. Manufacturer to submit product literature, data, test reports, certifications, and samples, of each type concrete masonry unit, as required. A. Manufacturer to submit color samples of various types and/or finishes under consideration from standard color palette, as required. B. Samples are representative of color and texture and may vary slightly during the manufacturing process CERTIFICATIONS A. Complies with ASTM C33 - Standard Specification for Concrete Aggregates. B. Complies with ASTM C90 - Load bearing Concrete Masonry Units, as applicable. C. Complies with ASTM C129 - Non-load bearing Concrete Masonry Units, as applicable. D. Complies with ASTM C Lightweight Aggregates for Concrete Masonry Units, as applicable. E. Conforms to National Concrete Masonry Association NCMA) Shapes and Sizes Manual, as applicable FIELD SAMPLES A. Manufacturer shall submit full size samples of each type and color of unit selected to illustrate texture, finish, coating, and color, as applicable MOCK-UPS A. Incorporate full size field samples into a mock-up for coordination of work specified in other sections and final approval of texture, finish, coatings and color, as applicable PACKING, SHIPPING, HANDLING, AND UNLOADING

3 A. Stack units on pallets in an "interlocking" fashion to facilitate shipping. If unable to "interlock", the top layer of Units Shall be mechanically secured. B. Each full pallet shall weigh between 3500 and 3750 pounds. C. Bag all architectural and specialty units using shrink-wrap coverings. D. Separate layers of ground face units with corrugated plastic sheeting. E. Unload pallets from delivery vehicle with forklift capable of safely lifting and carrying pallets. F. Handle units and pallets with care to avoid damage and breakage STORAGE AND PROTECTION A. Store pallets on level ground in single stacks only. B. Upon delivery, site manager shall cover pallets with waterproof material as protection from inclement weather; provide ventilation to avoid condensation WARRANTY A. Units shall be free from defects in materials for 1 year from date of shipment. B. ASTM C90, 8.1, 8.2 and 8.2.i, Finish and Appearance, applies. C. Inspect shipment for unit defects upon delivery. Defects shall be immediately reported to manufacturer. PART 2 PRODUCTS 2.01 MANUFACTURER A. Betco Supreme, Inc., 7920 Notes Drive, Manassas, VA 20109, , Fax: B. Nitterhouse Masonry Products, L.L.C., 859 Cleveland Avenue, Chambersburg, PA 17201, C. Other Owner/Engineer approved equal MATERIALS A. Structural Standard Concrete Masonry Units and Split-Face Concrete Masonry Units, as required. B. General

4 1. Unless otherwise indicated or specified, concrete masonry units shall be standard units with nominal face dimensions of 16 inch length x 8 inch height (15 5/8 x 7 5/8 actual) x 12 inch width. 2. Provide, or cut, all related matching accessory shapes and sizes as required for lintels, corners, jambs, sills, control joints, headers, bonding, and other special conditions. (a) Make all cuts with motorized masonry saw, using abrasive or diamond blade. C. Color 2.03 ACCESSORIES 3. Special units shall match color and texture of standard units. 4. Where units are placed so end of a unit is exposed, such as at corners or intersections, the exposed end of that block shall have a surface that matches the color and texture of the other units. 5. Provide units with normal weight aggregate conforming to ASTM C33 or lightweight aggregate conforming to ASTM C33 1, as required. 6. Normal weight aggregate shall be #10 architectural screened aggregate. 7. Cure all units in a moisture-controlled atmosphere to conform to ASTM C ASTM C90, Standard Specification for Load bearing Concrete Masonry Units, shall apply as required. 9. ASTM C129, Standard Specification for Non-load bearing Concrete Masonry Units, shall apply as required. 10. Architectural units shall contain integral water repellent admixture, Rheomix Rheopel TM by Master Builders, Inc., Cleveland, Ohio. 1. Submit color samples from manufacturer's Standard Palette of sample colors. A. MORTAR 1. Shall comply with ASTM C270, Standard Specification for Mortar for Unit Masonry. 2. Water for masonry mortar shall be clean and free of oils, acids, alkalis, salts, organic materials, or other substances that are harmful to mortar or any metal in the wall

5 3. Admixtures containing chlorides accelerate corrosion of steel reinforcing, ferrous ties and anchors, metal doors, and metal window frames. Chloride containing admixtures are, therefore, not recommended. B. GROUT 4. Aggregates for mortar must comply with ASTM C144, Standard Specification for Aggregates for Masonry Mortar. 5. Mortar shall contain integral water repellent admixture, Rheomix Rheopel TM by Master Builders, Inc., Cleveland, Ohio. 1. Shall comply with ASTM C476, Standard Specification for Grout for Masonry. 2. Water for grout shall be clean and potable. 3. Admixtures shall comply with ASTM C476, C. HORIZONTAL REINFORCEMENT 1. Ladur (DA 3200) 2-3/16" side rods, as manufactured by "Dur-o-wall", 625 Crane Street, Aurora, IL 60505, (800) FABRICATION TOLERANCES 2.05 FINISHES A. Shall comply with ASTM C90, Standard Specification for Load bearing Concrete Masonry Units, Article 7, Permissible Variations in Dimensions. A. Finished surfaces exposed in place shall conform to an approved sample consisting of not less than four units, representing the range of texture and color permitted SOURCE QUALITY CONTROL A. Purchaser or authorized representative shall be accorded proper facilities to inspect and sample units at place of manufacture from lots ready for delivery. B. Test results in accordance with ASTM C140, Standard Test Methods for Sampling and Testing Concrete Masonry Units and Related Units, shall be available upon request from the manufacturer. PART 3 EXECUTION 3.01 PREPARATION INSTALLATION A. Foundation must be level and clean, free of ice, dirt, oil, mud, and other substances.

6 A. Installers shall be experienced masons using best masonry practices. B. Lay up walls plumb and true, with courses level, accurately spaced and coordinated with other work. C. Pull units from more than one pallet at a time. D. Install only quality units. Reject defective or damaged units. E. As work progresses, build in all metal doorframes, window sashes, louvers, conduit, pipe, panel boards, and other items as required. Build in openings and recesses as required for work of other trades. F. Temporarily brace masonry walls that may be exposed to wind loads or other conditions that could affect stabilities. G. Install weep holes, vents, flashing at locations as indicated on plans and in strict accordance with best masonry flashing practices. H. Temperatures between 40 and 90' F (4.4 and C) are considered "normal" temperatures for masonry construction and do not require special procedures or weather protection protocols. When ambient temperatures fall below 40' F (4.4' C) or above 900 F (32.3' C), special construction procedures shall be considered to ensure the final construction is not adversely affected. I. Protect newly constructed walls by draping weather-resistant coverings over wall and extending them below any mortar susceptible to washout. J. Lay units with full mortar coverage on head and bed joints. K. Tool all mortar joints, when thumbprint hard, into a concave configuration. L. Remove mortar from the face of masonry units before it sets. M. Tuck point the joints of scored units for proper appearance FLASHING A. Install flashing at locations shown on the drawings and in strict accordance with the details and proper masonry flashing practices as outlined in "Concrete Masonry Handbook" CONTROL JOINTS A. Control joint locations shall be placed in accordance with the Concrete Masonry Handbook and best masonry practices. B. At a maximum spacing between joints shall not exceed 25 ft

7 C. Joints shall be located within 10 ft of comers, changes in wall direction, wall offsets, changes in wall height, wall openings and directly below shelf angles WEEP HOLES AND VENTS A. Install weep holes and vents at proper intervals at courses above grade, above flashing, and at any water stops over windows, doors and beams HORIZONTAL REINFORCEMENT A. Install horizontal reinforcement every course. B. Place reinforcement directly on masonry and place mortar over wire to form bed joint CLEANING A. Minimize mortar and grout smears on face of units during installation. B. Mortar droppings can be removed with trowel or chisel after being allowed to harden. C. Remove remaining mortar with stiff fiber brush. D. Clean completed walls with masonry cleaner, strictly following manufacturer's directions. Rinse thoroughly. E. If additional cleaning is required, the use of a detergent masonry cleanser formulated for concrete masonry may be used, strictly following the manufacturer's instructions including thorough pre-wetting of the walls and thorough rinsing. END OF SECTION

8 SECTION UNIT MASONRY ASSEMBLIES PART I - GENERAL 1.1 RELATED DOCUMENTS: Drawings and general provisions of the Contract, including General and Supplementary Conditions and Division 1 Specification Sections, apply to this Section. 1.2 SUMMARY: This Section includes: 1. CMU 2. Masonry joint reinforcement. 3. Ties and anchors. 4. Miscellaneous masonry accessories. 5. Mortar and grout 6. Masonry cell insulation 1.3 SUBMITTALS A. Product Data: For each different masonry unit, accessory, and other manufactured product specified. B. Samples: For verification of specified units and for selection of full range of CMU and mortar color. C. Qualification Data: For firms and persons specified in Quality Assurance Article. D. Material Test Reports: From a qualified testing agency indicating and interpreting test results of the following for compliance with requirements indicated: 1. Each type of masonry unit required. 2. Mortar complying with property requirements of ASTM C Grout mixes complying with compressive strength requirements of ASTM C 476. Include description of type and proportions of grout ingredients. E. Material Certificates: Signed by manufacturers certifying that each of the following items,complies with requirements: 1. Each type of masonry unit required. 2. Each cement product required for mortar and grout, including name of manufacturer, brand, type, and weight slips at time of delivery. F. Cold-Weather Procedures: Detailed description of methods, materials, and equipment to be used to comply with cold-weather requirements.

9 . 1.4 DELIVERY, STORAGE, AND HANDLING A. Store masonry units on elevated platforms in a dry location. If units are not stored in an enclosed location, cover tops and sides of stacks with waterproof sheeting, securely tied. If units become wet, do not install until they are dry. 1. Protect Type I concrete masonry units from moisture absorption so that, at the time of installation, the moisture content is not more than the maximum allowed at the time of delivery. B. Store cementitious materials on elevated platforms, under cover, and in a dry location. Do not use cementitious materials that have become damp. C. Store aggregates where grading and other required characteristics can be maintained and contamination avoided. D. Deliver preblended, dry mortar mix in moisture-resistant containers designed for lifting and emptying into dispensing silo, Store preblended, dry mortar mix in delivery containers on elevated platforms, under cover, and in a dry location or in a metal dispensing silo with weatherproof cover. E. Store masonry accessories, including metal items, to prevent corrosion and accumulation of dirt and oil. S1.5 PROJECT CONDITIONS A. Protection of Masonry: During construction, cover tops of walls, projections, and sills with waterproof sheeting at end of each day's work. Cover partially completed masonry when construction is not in progress. Extend cover a minimum of 24 inches down both sides and hold cover securely in place. B. Stain Prevention: Prevent grout, mortar, and soil from staining the face of masonry to be left exposed or painted. Immediately remove grout, mortar, and soil that come in contact with such masonry. C. Cold-Weather Requirements: Do not use frozen materials or materials mixed or coated with ice or frost. Do not build on frozen substrates. Remove and replace unit masonry damaged by frost or by freezing conditions. Comply with cold-weather construction requirements contained in ACI 530. I/ASCE 6/TMS Cold-Weather Cleaning: Use liquid cleaning methods only when air temperature is 40 deg F and above and will remain so until masonry has dried, but not less than 7 days after completing cleaning. D. Hot-Weather Requirements: Protect unit masonry work when temperature and humidity conditions produce excessive evaporation of water from mortar and grout. Provide artificial shade and wind breaks and use cooled materials as required.

10 PART 2- PRODUCTS 1. When ambient temperature exceeds 100 deg F, or 90 deg F with a wind velocity greater than 8 mph, do not spread mortar beds more than 48 inches ahead of masonry. Set masonry units within one minute of spreading mortar. 2.1 CONCRETE MASONRY UNITS A. Manufacturer: Subject to the following requirements provide material of one of the following: 1. Fizzano, Crum Lynne, PA 2. Clayton, Lakewood, NJ 3. Trenwyth, Emigsville, PA B. General: Provide shapes indicted and as follows: 1. Provide special shapes for lintels, comers, jambs, bonding, and other special conditions. 2. Provide square edged units for outside comers, unless indicated as bullnose. C. Concrete Masonry Units: ASTM C 90 and as follows: 1. Unit Compressive Strength: Provide units with minimum average net area compressive strength of 1900 psi. 2. Weight Classification: Normal weight, unless other indicated. 3. Provide Type I, moisture controlled units. 4. Size (width): Manufactured to the following dimensions: 8 inches nominal; 7 5/8 inches actual. 5. Exposed Faces: Manufacturer's standard (minimum 25) colors and plane for interior and split face texture for exterior walls, 8" x 16" nominal, unless otherwise indicated. D. Integral Water Repellant: Provide units made with integral water repellant for exterior walls. 1. Integral Water Repellent: Liquid polymeric, integral water-repellent admixture that does not reduce flexural bond strength. Units made with integral water repellent, when tested as a wall assembly made with mortar containing integral water-repellent manufacturer's mortar additive according to ASTM E 514, with test period extended to 24 hours, show no visible water or leaks on the back of test specimen. a. Products: 1) Addiment Incorporated; Block Plus W-10.

11 2.2 MORTAR AND GROUT MATERIALS 2) Grace Construction Products, a unit of W. R. Grace & Co. - Conn.; Dry-B lock. 3) Master Builders, Inc.; Rheopel. A. Portland Cement: ASTM C 150, Type I or II, except Type III may be used for coldweather construction. Provide natural color or white cement as required to produce mortar color selected. B. Hydrated Lime: ASTM C 207, Type S. C. Portland Cement-Lime Mix: Packaged blend of portland cement complying with ASTM C 150, Type I or Type III, and hydrated lime complying with ASTM C 207. D. Aggregate for Mortar: ASTM C 144; except for joints less than 1/4 inch thick, use aggregate graded with 100 percent passing the No. 16 sieve. 1. Colored-Mortar Aggregates: Natural-colored sand or ground marble, granite, or other sound stone; of color necessary to produce required mortar color. E. Aggregate for Grout: ASTM C 404. F. Mortar Pigments: Natural and synthetic iron oxides and chromium oxides, compounded for use in mortar mixes. Use only pigments with a record of satisfactory performance in masonry mortar. G. Cold-Weather Admixture: Nonchloride, nonconosive, accelerating admixture complying with ASTM C 494, Type C, and recommended by the manufacturer for use in masonry mortar of composition indicated. H. Water-Repellent Admixture: Liquid water-repellent mortar admixture intended for use with concrete masonry units, containing integral water repellent by same manufacturer. 1. Products: I. Water: Potable. 2.3 REINFORCEMENT: a. Addiment Incorporated; Mortar Tite. b. Grace Construction Products, a unit of W. R. Grace & Co. - Conn.; Dry- Block Mortar Admixture. c. Master Builders, Inc. Rheomix R.heopel. Uncoated Steel Reinforcing Bars: ASTM A 615 or ASTM A 996 Grade MASONRY JOINT REINFORCEMENT A. General: ASTM A 951 and as follows: Galvanized steel.

12 1. Wire Size for Rods: W2.8 or inch diameter. 2. Provide in lengths of not less than 10 feet, with prefabricated corner and tee units where required. B. For single-wythe concrete masonry, provide continuous 2 parallel rods with truss configuration connectors spaced not more than 16 inches o.c vertically. 2.5 MASONRY CLEANERS A. Job-Mixed Detergent Solution: Solution of 1/2-cup dry measure tetrasodium polyphosphate and 1/2-cup dry measure laundry detergent dissolved in 1 gal. of water. B. Proprietary Acidic Cleaner: Manufacturers standard-strength cleaner designed for removing mortar/grout stains, efflorescence, and other new construction stains from new masonry without discoloring or damaging masonry surfaces. Use product expressly approved for intended use by cleaner manufacturer and manufacturer of masonry units being cleaned. 2.6 MORTAR AND GROUT MIXES A. General: Do not use admixtures, including pigments, air-entraining agents, accelerators, retarders, water-repellent agents, antifreeze compounds, or other admixtures, unless otherwise indicated, Do not use calcium chloride in mortar or grout. B. Mortar for Unit Masonry: Comply with ASTM C 270, Property Specification. 1. Limit cementitious materials in mortar to portland cement, mortar cement, and lime. 2. For masonry below grade, in contact with earth, and where indicated, use Type 3. M. For exterior, above-grade walls and parapet walls; for interior load-bearing walls; for and for other applications where another type is not indicated, use Type S. C. Grout for Unit Masonry: Comply with ASTM C Use grout of type indicated or, if not otherwise indicated, of type fine or coarse that will comply with Table 5 of ACI 530.1/ASCE 6/TMS 602 for dimensions of grout spaces and pour height. 2: Provide grout with a slump of 8 to 11 inches as measured according to ASTM C MASONRY-CELL INSULATION Molded-Polystyrene Insulation Units: Rigid, cellular thermal insulation formed by the expansion of polystyrene-resin beads or granules in a closed mold to comply with ASTM C 578, Type I. Provide specially shaped units designed for installing in cores of masonry units. 1. Products:

13 PART 3 - EXECUTION 3.1 EXAMINATION a. Concrete Block Insulating Systems; Korfil. b. Shelter Enterprises Inc.; Omni Core. Examine conditions, with Installer present, for compliance with requirements for installation tolerances and other conditions affecting performance. For the record, prepare written report, endorsed by Installer, listing conditions detrimental to performance. Verify that foundations are within tolerances specified. Verify that reinforcing dowels are properly placed. Proceed with installation only after unsatisfactory conditions have been corrected. Before installation, examine rough-in and built-in construction to verify actual locations of piping connections. 3.2 INSTALLATION, GENERAL A. Thickness: Build walls and other masonry construction to the full thickness shown. B. Build chases and recesses to accommodate items specified in this Section and in other Sections of the Specifications. C. Leave openings for equipment to be installed before completing masonry. After installing equipment, complete masonry to match the construction immediately adjacent to the * opening. D. Cut masonry units with motor-driven saws to provide clean, sharp, unchipped edges. Cut units as required to provide a continuous pattern and to fit adjoining construction. Where possible, use MI-size units without cutting. Allow units cut with water-cooled saws to dry before placing, unless wetting of units is specified. Install cut units with cut surfaces and, where possible, cut edges concealed. E. Perform field test to determine if wetting is required. Draw a circle the size of a quarter on a brick and place 20 drops of water in the circle; if water is absorbed within 1-1/2 minutes, the brick requires wetting. 3.3 CONSTRUCTION TOLERANCES A. Comply with tolerances in ACI 530. I/ASCE 6/TMS 602 and the following: B. For conspicuous vertical lines, such as external corners, door jambs, reveals, and expansion and control joints, do not vary from plumb by more than 1/4 inch in 20 feet, nor 1/2 inch maximum. C. For vertical alignment of exposed head joints, do not vary from plumb by more than 1/4 inch in 10 feet, nor 1/2 inch maximum. D. For conspicuous horizontal lines, such as exposed lintels, sills, parapets, and reveals, do not vary from level by more than 1/4 inch in 20 feet, nor 1/2 inch maximum.

14 F. For exposed bed joints, do not vary from thickness indicated by more than plus or minus 1/8 inch, with a maximum thickness limited to 1/2 inch. Do not vary from bed-joint thickness of adjacent courses by more than 1/8 inch. F. For exposed head joints, do not vary from thickness indicated by more than plus or minus 1/8 inch. Do not vary from adjacent bed-joint and head-joint thicknesses by more than 1/8 inch. 3.4 LAYING MASONRY WALLS A. Lay out walls in advance for accurate spacing of surface bond patterns with uniform joint thicknesses and, for accurate location of openings, movement-type joints, returns, and offsets. Avoid using less-than-half-size units, particularly at corners, jambs, and, where possible, at other locations. B. Bond Pattern for Exposed Masonry: Lay exposed masonry in the following bond pattern; do not use units with less than nominal 8-inch horizontal face dimensions at corners or jambs. 1. One-half running bond with vertical joint iii each course centered on units in courses above and below. C. Stopping and Resuming Work: In each course, rack back one-half-unit length for onehalf running bond; do not tooth. Clean exposed surfaces of set masonry, wet clay masonry units lightly if required, and remove loose masonry units and mortar before laying fresh masonry. D. Built-in Work: As construction progresses, build in items specified under this and other Sections of the Specifications. Fill in solidly with masonry around built-in items. E. Fill space between hollow-metal frames and masonry solidly with mortar, unless otherwise indicated. F. Where built in items are to be embedded in cores of hollow masonry units, place a layer of metal lath in the joint below and rod mortar or grout into core. G. Fill cores in hollow concrete masonry units with grout 24 inches under bearing plates, beams, lintels, posts, and similar items, unless otherwise indicated. H. Install molded-polystyrene insulation units into masonry unit cells before laying units. 3.5 MORTAR BEDDING AND JOINTING A. Lay hollow masonry units as follows: 1. With full mortar coverage on horizontal and vertical face shells. 2. Bed webs in mortar in starting course on footings and in all courses of piers, columns, and pilasters, and where adjacent to cells or cavities to be filled with grout.

15 3. For starting course on footings where cells are not grouted, spread out full mortar bed, including areas under cells. B. Tool exposed joints slightly concave when thumbprint hard, using a jointer larger than the joint thickness, unless otherwise indicated. 3.6 PLACING REINFORCEMENT Comply with requirements in ACI 530, 1/ASCE 6/TMS MASONRY JOINT REINFORCEMENT A. General: Provide continuous masonry joint reinforcement as indicated. Install entire length of longitudinal side rods in mortar with a minimum cover of 5/8 inch on exterior side of walls, 1/2 inch elsewhere. Lap reinforcement a minimum of 6 inches. 1. Space reinforcement not more than 16 inches o.c. 2. Space reinforcement notmore than 8 inches o.c. in foundation walls. 3. Provide reinforcement not more than 8 inches above and below wall openings and extending 12 inches beyond openings. a. Reinforcement above is in addition to continuous reinforcement. B. Cut or interrupt joint reinforcement at control and expansion joints, unless otherwise indicated. C. Provide continuity at corners and wall intersections by using "U and "T" sections. Cut and bend reinforcing units as directed by manufacturer for continuity at returns, offsets, enclosures, and other special conditions. 3.8 REPAIRING, POINTING, AND CLEANING A. Remove and replace masonry units' that are loose,, chipped, broken, stained, or otherwise damaged or that do not match adjoining units. Install new units to match adjoining units; install in fresh mortar, pointed to eliminate evidence of replacement. B. Pointing: During the tooling of joints, enlarge voids and holes and completely fill with mortar. Point up joints, including corners, openings, and adjacent construction, to provide a neat, uniform appearance, Prepare joints for sealant application. C. In-Progress Cleaning: Clean unit masonry as work progresses by dry brushing to remove mortar fins and smears before tooling joints. D. Final Cleaning: After mortar is thoroughly set and cured, clean exposed masonry as follows: 1. Remove large mortar particles by hand with wooden paddles and nonmetallic scrape hoes or chisels.

16 2. Test cleaning methods on sample wall panel; leave one-half of panel uncleaned for comparison purposes. Obtain owner's approval of sample cleaning before proceeding with cleaning of masonry. 3. Protect adjacent surfaces from contact with cleaner by covering them with liquid strippable masking agent, polyethylene film, or waterproof masking tape. 4. Wet wall surfaces with water before applying cleaners; remove cleaners promptly by rinsing the surfaces thoroughly with clear water. 5. Clean masonry with a proprietary acidic cleaner applied according to manufacturer's written instructions. 3.9 MASONRY WASTE DISPOSAL Recycling: Unless otherwise indicated, excess masonry materials are Contractor's' property. At completion of unit masonry work, remove from Project site. END OF SECTION