OSUT_1_04_21_13_13_Nonbearing_Masonry_Veneer_Steel_Stud_Walls.pdf

OSUT-AR RANGE PROJECT FY19

SECTION 04 21 13.13

NONBEARING MASONRY VENEER/STEEL STUD WALLS

10/07

PART 1 GENERAL

1.1 REFERENCES

The publications listed below form a part of this specification to the extent referenced. The publications are referred to within the text by the basic designation only.

AMERICAN INSTITUTE OF STEEL CONSTRUCTION (AISC)

AISC 325 (2005) Manual of Steel Construction

AMERICAN SOCIETY OF HEATING, REFRIGERATING AND AIR-CONDITIONING

ENGINEERS (ASHRAE)

ASHRAE FUN IP (2009) Fundamentals Handbook, I-P Edition

ASHRAE FUN SI (2009) Fundamentals Handbook, SI Edition

AMERICAN WELDING SOCIETY (AWS)

AWS D1.3/D1.3M (2008; Errata 2008) Structural Welding Code - Sheet Steel

APA - THE ENGINEERED WOOD ASSOCIATION (APA)

APA PS 1 (1995) Voluntary Product Standard for Construction and Industrial Plywood

ASTM INTERNATIONAL (ASTM)

ASTM A 123/A 123M (2009) Standard Specification for Zinc (Hot-Dip Galvanized) Coatings on Iron and Steel Products

ASTM A 153/A 153M (2009) Standard Specification for Zinc Coating (Hot-Dip) on Iron and Steel Hardware

ASTM A 36/A 36M (2008) Standard Specification for Carbon Structural Steel

ASTM A 653/A 653M (2009a) Standard Specification for Steel Sheet, Zinc-Coated (Galvanized) or Zinc-Iron Alloy-Coated (Galvannealed) by the Hot-Dip Process

ASTM A 82/A 82M (2007) Standard Specification for Steel Wire, Plain, for Concrete Reinforcement

ASTM C 1002 (2007) Standard Specification for Steel Self-Piercing Tapping Screws for the Application of Gypsum Panel Products or Metal Plaster Bases to Wood Studs or Steel Studs

ASTM C 1072 (2006) Standard Test Method for Measurement of Masonry Flexural Bond Strength

ASTM C 1177/C 1177M (2008) Standard Specification for Glass Mat Gypsum Substrate for Use as Sheathing

ASTM C 1396/C 1396M (2009a) Standard Specification for Gypsum Board

ASTM C 216 (2007a) Facing Brick (Solid Masonry Units Made from Clay or Shale)

ASTM C 270 (2008a) Standard Specification for Mortar for Unit Masonry

ASTM C 494/C 494M (2008a) Standard Specification for Chemical Admixtures for Concrete

ASTM C 578 (2009e1) Standard Specification for Rigid, Cellular Polystyrene Thermal Insulation

ASTM C 591 (2009) Standard Specification for Unfaced Preformed Rigid Cellular Polyisocyanurate Thermal Insulation

ASTM C 665 (2006) Mineral-Fiber Blanket Thermal Insulation for Light Frame Construction and Manufactured Housing

ASTM C 67 (2009) Standard Test Methods for Sampling and Testing Brick and Structural Clay Tile

ASTM C 744 (2009) Prefaced Concrete and Calcium Silicate Masonry Units

ASTM C 780 (2009) Preconstruction and Construction Evaluation of Mortars for Plain and Reinforced Unit Masonry

ASTM C 90 (2009) Loadbearing Concrete Masonry Units

ASTM C 91 (2005) Masonry Cement

ASTM C 954 (2007) Steel Drill Screws for the Application of Gypsum Panel Products or Metal Plaster Bases to Steel Studs from

0.033 in. (0.84 mm) to 0.112 in. (2.84 mm) in Thickness

ASTM C 955 (2009a) Load-Bearing (Transverse and

Axial) Steel Studs, Runners (Tracks), and Bracing or Bridging for Screw Application of Gypsum Panel Products and Metal Plaster Bases

ASTM D 1056 (2007) Standard Specification for Flexible Cellular Materials - Sponge or Expanded Rubber

ASTM D 1330 (2004) Rubber Sheet Gaskets

ASTM D 1667 (2005) Flexible Cellular Materials - Poly (Vinyl Chloride) Foam (Closed-Cell)

ASTM D 2103 (2008) Standard Specification for Polyethylene Film and Sheeting

ASTM D 226/D 226M (2009) Standard Specification for Asphalt-Saturated Organic Felt Used in Roofing and Waterproofing

1.2 SUBMITTALS

Government approval is required for submittals with a "G" designation;

submittals not having a "G" designation are for information only. When used, a designation following the "G" designation identifies the office that will review the submittal for the Government. Submit the following in accordance with Section 01 33 00 SUBMITTAL PROCEDURES:

SD-02 Shop Drawings

Detail Drawings

Detail drawings as specified.

SD-04 Samples

Expansion Joint Materials

SD-06 Test Reports

Calculations

Calculations demonstrating the structural adequacy of steel lintels for the calculated gravity loads being supported; this analysis shall be in accordance with AISC 325. Test results demonstrating that the veneer anchors are structurally adequate to resist the specified loadings shall be submitted for approval.

Calculations demonstrating the insulation shown on the drawings provides the specified U-value for heat transmission of the completed exterior wall construction; this analysis shall be in accordance with ASHRAE FUN IP. Manufacturer's descriptive data and installation instructions for the insulation, the vapor barrier and the moisture barrier.

SD-07 Certificates

Joint Reinforcement Expansion Joint Materials Insulation Exterior Sheathing Moisture Barrier Vapor Retarder Veneer Anchors Welding

Certificates stating that the materials and welders meet the requirements specified. Each certificate shall be signed by an authorized certification official and shall include their organization and position and shall identify the products covered under their certifying signature.

1.3 QUALITY ASSURANCE

1.3.1 Sample Panel

After the material samples are approved and prior to starting masonry work, build a sample masonry panel on the project site where directed. The sample panel shall be not less than 6 feet long by 4 feet high of typical wall thickness for the construction represented. The panel shall show color range, texture, bond pattern, expansion joints, and cleaning of the masonry as required in the work. The panel shall also show cold-formed steel framing, insulation, gypsum wallboard, gypsum sheathing, moisture barrier, vapor barrier, veneer anchors, joint reinforcement, steel shelf angles, flashing and weep holes. Use the approved sample panel as a standard of workmanship required in the actual installation; protect the sample panel from weather and construction operations. Do not remove the panel until the masonry veneer/steel stud wall work has been completed and accepted.

1.3.2 Efflorescence Tests

Perform efflorescence tests by an approved commercial testing laboratory.

Sampling for the tests shall be the responsibility of the Contractor.

Sample and test brick for efflorescence in accordance with ASTM C 67 and the rating shall be: "not effloresced".

1.3.3 Detail Drawings

Submit details of cold-formed steel framing and support around openings, including framing connections, steel lintels, steel shelf angles, attachment to other building elements and bridging. Drawings shall indicate thickness, material, dimensions, protective coatings, and section properties of all steel lintels and shelf angles used in exterior wall framing. Drawings shall also indicate size and type of all fasteners including size and type of all welds.

1.4 DELIVERY, STORAGE, AND HANDLING

Deliver cementitious materials in unopened containers plainly marked and labeled with manufacturer's names and brands. Store cementitious materials in dry, weather-tight enclosures or covers. The masonry products shall be stored off the ground and protected from inclement weather. Materials shall be delivered and handled avoiding chipping, breakage, bending or other damage, and contact with soil or other contaminating materials.

Store sand and other aggregates preventing contamination or segregation and under a weather-tight covering permitting good air circulation. Finish of the framing members shall be maintained at all times, using an approved high zinc dust content galvanizing repair paint whenever necessary to prevent the formation of rust. Store insulation, moisture barrier, and gypsum sheathing in dry, well ventilated, weather-tight areas protected from sunlight and excessive heat. Air infiltration type vapor barrier shall be stored in accordance with the manufacturer's recommendations.

PART 2 PRODUCTS

2.1 VENEER WYTHE

The source of masonry materials which will affect the appearance of the finished work shall not be changed after the work has started except with the Contracting Officer's approval.

2.1.1 Clay Brick

Clay Brick shall be as specified in Section 04 20 00 MASONRY.

2.1.2 Cast Stone Trim Items

Cast Stone Trim Items shall be as specified in Section 04 20 00 MASONRY.

2.2 MORTAR

Provide mortar conforming to ASTM C 270, Type S. Mortar mix shall be based on proportion specifications. Laboratory testing of mortar shall be in accordance with the preconstruction evaluation of mortar section of ASTM C 780. Cement shall have a low alkali content and be of one brand.

Provide aggregates from one source.

2.2.2 Admixtures

In cold weather, a non-chloride based accelerating admixture may be used subject to approval. Accelerating admixtures shall be non-corrosive, contain less than 0.2 percent chlorides, and conform to ASTM C 494/C 494M, Type C.

2.3 JOINT REINFORCEMENT

Provide joint reinforcement of steel wire conforming to ASTM A 82/A 82M.

Fabrication shall be by welding. Tack welding will not be permitted.

Reinforcement shall be zinc-coated after fabrication in accordance with ASTM A 153/A 153M, Class B-2. Joint reinforcement shall consist of at least 1 continuous longitudinal wire in the veneer wythe. Minimum wire cross section shall be 0.017 square inches.

2.4 COLD-FORMED STEEL FRAMING

Provide cold-formed framing consisting of steel studs, top and bottom tracks, runners, horizontal bridging, and other cold-formed members and other accessories. All members and components made of sheet steel shall be hot-dip galvanized in accordance with ASTM A 653/A 653M with a minimum coating thickness of G 60. Framing covered herein shall be used only in framing the exterior masonry veneer steel stud wall system as indicated on the detail drawings and for miscellaneous framing at the gable entry ways and soffits. Metal framing for interior partitions is specified in Section

09 22 00 METAL SUPPORT ASSEMBLIES.

2.4.1 Steel Studs

Furnish studs as shown in the contract drawings.

2.4.2 Runners, Tracks, Bridging and Accessories

Cold-formed steel sheet framing members, components, and accessories, other than the steel studs, shall conform to ASTM C 955 and be of steel conforming to ASTM A 653/A 653M, Grade 33, having a minimum yield strength of 33,000 psi.

2.5 INSULATION

Comply with EPA requirements in accordance with Section 01 62 35 RECYCLED /

RECOVERED MATERIALS.

2.5.1 Blanket Insulation

Insulation placed between the steel studs shall be batt or blanket type mineral wool conforming to ASTM C 665, Type I.

2.5.2 Rigid Board-Type Insulation

Insulation for wall cavities shall be rigid board-type insulation. Rigid board-type insulation shall be either polyisocyanurate conforming to ASTM C 578, Type I or II, Grade 2 or polyurethane conforming to ASTM C 591.

Insulation thickness shall be sufficient to provide an R-value as indicated on drawings.

2.6 GYPSUM WALLBOARD

Gypsum wallboard that is installed on the interior side of the cold-formed steel framing system shall be as specified in Section 09 29 00 GYPSUM BOARD.

2.7 EXTERIOR SHEATHING

Gypsum sheathing that is installed on the exterior side of the cold-formed steel framing system shall have a minimum thickness of 5/8 inch and shall be 4 feet wide. Glass mat gypsum sheathing shall conform to ASTM C 1396/C 1396M and ASTM C 1177/C 1177M. Glass mat gypsum sheathing shall have a water-resistant core with a water-resistant glass mat embedded onto core and shall have a zero flame, zero smoke developed, and shall have mold and mildew resistant surface.

2.9 VENEER ANCHORS

Anchor assemblies for the attachment of the masonry veneer to the cold-formed steel framing, structural steel and/or concrete beam and column members, and concrete floor slabs shall be as shown. Length of anchor wires shall be such that the outermost wires lie between 1-1/4 inch from each face of the masonry veneer. Provide anchors wires without drips.

Wires for veneer anchors shall be rectangular or triangular hoops formed from 3/16 inch diameter steel wire conforming to ASTM A 82/A 82M. Anchor assemblies, including wires and anchor plates, shall be hot-dip galvanized conforming to ASTM A 153/A 153M, Class B-2. The veneer anchor shall have a minimum capacity of 200 pounds. The load-displacement capacity of each veneer anchor, both in direct pull-out for tension and compression, shall be not less than 2000 pounds/inch (or a deflection of 0.05 inches/100 pounds of load in tension or compression). In the direction perpendicular to the masonry veneer, the anchor assembly shall have a maximum play of 1/16 inch.

2.9.1 Adjustable Pintle-Eye Type Wire Anchors

Adjustable pintle-eye type wall anchors shall be two pieces rectangular type double pintle anchors.

2.9.2 Dovetail Anchors

Dovetail slots are specified in Section 03 31 00.00 10 CAST-IN-PLACE

STRUCTURAL CONCRETE.

2.10 CONNECTIONS

Screws, bolts and anchors shall be hot-dip galvanized in accordance with ASTM A 123/A 123M or ASTM A 153/A 153M as appropriate.

2.10.1 Framing Screws, Bolts and Anchors

Screws, bolts and anchors used in the assembly of the cold-formed steel framing system shall be as shown. Screw, bolt and anchor sizes shall be shown on the detail drawings.

2.10.2 Welding

Design welded connections and perform all welding in accordance with AWS D1.3/D1.3M. Welders shall be qualified in accordance with AWS D1.3/D1.3M. All welds shall be cleaned and touched-up with zinc-rich paint.

2.10.4 Gypsum Sheathing Screws

Screws for attachment of gypsum sheathing to cold-formed steel framing shall conform to ASTM C 1002, Type S.

2.11 SYNTHETIC RUBBER WASHERS

Synthetic rubber washers for placement between veneer anchors and the moisture barrier on the outside face of the exterior sheathing shall conform to ASTM D 1330, Grade I.

2.12 EXPANSION JOINT MATERIALS

Expansion joint materials shall be bellows or U-shaped type conforming to Section 07 57 13 FLASHING AND SHEET METAL. Premolded type shall be closed-cell cellular rubber conforming to ASTM D 1056 or closed-cell vinyl or polyvinyl chloride conforming to ASTM D 1667.

2.13 FLASHING

Copper or stainless steel flashing shall conform to the requirements in Section 07 57 13 FLASHING AND SHEET METAL. Flashing shall be supplied in a continuous sheet extending from the exterior sheathing across the cavity and through the masonry veneer as shown.

2.14 STEEL LINTELS

Steel shapes used for lintels shall conform to ASTM A 36/A 36M. Provide lintels and shelf angles as shown. These steel members shall be hot-dip galvanized in accordance with ASTM A 123/A 123M.

2.15 CAULKING AND SEALANTS

Caulking and sealants shall be as specified in Section 07 92 00 JOINT

SEALANTS.

PART 3 EXECUTION

3.1 GENERAL INSTALLATION REQUIREMENTS

Wall sections, types of construction and dimensions shall be as shown.

Metal door and window frames and other special framing shall be built and anchored into the wall system as indicated. Submit Calculations as specified in the Submittals paragraph.

3.2 STEEL STUD WALL FRAMING

The top track of the stud wall system shall be slip jointed to accommodate vertical deflections of the supporting members as shown on the drawings.

Anchor top and bottom tracks by one anchor at each stud location as shown on the drawings. Both flanges of all steel studs shall be securely fastened with screws to the flanges of the top and bottom tracks as shown on the drawings. All details for affixing steel studs to runners and all other sheet steel framing members along with all details necessary for anchorage of the steel stud wall system to the building structural systems shall be as shown on the drawings. Provide horizontal bridging as necessary. Space studs as indicated on the drawings. Coordinate stud spacing with sheathing and anchor requirements.

3.4 INSULATION

The actual installed thickness of insulation shall provide a maximum thermal R as indicated on drawings for the completed exterior wall construction as determined in accordance with ASHRAE FUN IP. Provide insulation thickness as shown on the approved drawings. Installation, except as otherwise specified or shown, shall be in accordance with the manufacturer's instructions which shall be approved by the Contracting Officer. Install insulation between wall framing members. Rigid insulation shall be installed in accordance with the manufacturer's instructions with proper connections through the insulation to prevent the insulation from carrying loads directly. Insulation with facings shall be secured to the sides of the framing members to provide a continuous seal so that the entire weight of the insulation is carried by the framing members. Where electrical outlets, ducts, pipes, vents or other utility items occur, place insulation on the dry side of the item away from excessive humidity.

3.6 EXTERIOR SHEATHING

Install sheathing on the exterior face of the cold-formed steel framing system with self-drilling screws. Locate screws a minimum of 3/8 inch from the ends and edges of sheathing panels and spaced not more than 8 inches on each supporting member except at vertical slip joints, the sheathing shall be connected to the vertical studs to prevent movement of the slip joint.

Edges and ends of gypsum sheathing panels shall be butted snugly with vertical joints staggered to provide full and even support for the moisture barrier. Holes and gaps resulting from abandoned screw installations, from damage to panels, and from cutting and fitting of panels at junctures with doors, windows, foundation walls, floor slabs and other similar locations shall be filled with exterior rubber-base caulk.

3.8 VENEER ANCHORS

Attach veneer anchors with screws through the sheathing and rigid insulation to the support members at the locations shown. When rigid insulation is used, the method of connecting the veneer anchor through the insulation shall be approved by the Contracting Officer. Install veneer anchors with the outermost wires lying between 5/8 inch from each face of the masonry veneer. Use synthetic rubber washers between the anchor connector plates and the moisture barrier. Use a clutch torque slip screw gun on screws attaching veneer anchors to cold-formed steel members.

Veneer anchors with corrugated sheet metal or wire mesh members extending across the wall cavity shall not be used. There shall be one veneer anchor for each two square feet of wall and shall be attached to supports with a maximum spacing of 24 inches on center. For pintle-eye anchors the vertical distance between the pintle section horizontal wires and the eye section horizontal wires shall not exceed 1/2 inch. Install dovetail slots as specified in the Section 03 31 00.00 10 CAST-IN-PLACE STRUCTURAL CONCRETE.

3.9 FLASHING

Provide continuous flashing at the bottom of the wall cavity just above grade. Flashing shall also be provided above and below openings at lintels and sills, at shelf angles, and as indicated on the drawings. Flashing shall be as detailed and as specified in Section 07 57 13 FLASHING AND SHEET METAL. Flashing shall be lapped a minimum of 6 inches at joints and shall be sealed with a mastic as recommended by the flashing manufacturer.

Ends over doors, windows and openings shall be turned up and secured.

Flashing shall be lapped under the moisture barrier a minimum of 6 inches and securely attached to the gypsum sheathing. Flashing shall extend through the exterior face of the masonry veneer and shall be turned down to form a drip.

3.10 MASONRY VENEER

Construct exterior masonry wythes to the thickness indicated on the drawings. A cavity consisting of a 2 inch minimum width air space will be provided between the moisture barrier and the masonry veneer. Masonry veneer shall not be installed until the exterior sheathing, moisture barrier, veneer anchors and flashing have been installed. Take extreme care to avoid damage to the moisture barrier and flashing during construction of the masonry veneer. Any portion of the moisture barrier and flashing that is damaged shall be repaired or replaced prior to completion of the veneer. Masonry bond pattern shall be as indicated on the drawings. Vertical joints on alternating courses shall be aligned and kept vertically plumb. Solid masonry units shall be laid in a non-furrowed full bed of mortar, beveled and sloped toward the center of the wythe on which the mortar is placed. Units shall be shoved into place so that the vertical mortar joints are completely full and tight. Units that have been disturbed after the mortar has stiffened shall be removed, cleaned and relaid. Remove mortar which protrudes more than 1/2 inch into the cavity space. Provide means to ensure that the cavity space is kept clean of mortar droppings and other loose debris. Chases and raked-out joints shall be kept free from mortar and debris. Faces of units used in finished exposed areas shall be free from chipped edges, material texture or color defects or other imperfections distracting from the appearance of the finished work.

3.10.1 Surface Preparation

Surfaces on which masonry is to be laid shall be cleaned of laitance or other foreign material. No units having a film of water shall be laid.

3.10.2 Hot Weather Construction

Temperatures of masonry units and mortar shall not be greater than 120 degrees F when laid. Masonry erected when the ambient air temperature is more than 99 degrees F in the shade and when the relative humidity is less than 50 percent shall be given protection from the direct exposure to wind and sun for 48 hours after the installation.

3.10.3 Cold Weather Construction

Temperatures of masonry units and mortar shall not be less than 40 degrees F when laid. When the ambient air temperature is 32 degrees F or less, masonry veneer under construction shall be protected and maintained at a temperature greater than 32 degrees F for a period of 48 hours after installation. Submit for approval the proposed method of maintaining the temperature within the specified range prior to implementation. No units shall be laid on a surface having a film of frost or water.

3.10.4 Tolerances

Masonry shall be laid plumb, level and true to line within the tolerances specified in TABLE 1. All masonry corners shall be square unless otherwise indicated on the drawings.

TABLE 1

Variation From Plumb

In adjacent units 1/8 inch In 10 feet 1/4 inch In 20 feet 3/8 inch In 40 feet or more 1/2 inch

Variation From Level Or Grades

In 10 feet 1/8 inch In 20 feet 1/4 inch In 40 feet or more 1/2 inch

Variation From Linear Building Lines

In 20 feet 1/2 inch In 40 feet or more 3/4 inch

Variation From Cross Sectional Dimensions Of Walls

Plus 1/2 inch Minus 1/4 inch

3.10.5 Mixing of Mortar

Mix mortar in a mechanically operated mortar mixer for at least 3 minutes but not more than 5 minutes. Measurement of ingredients for mortar shall be by volume. Measurement of sand shall be accomplished by the use of a container of known capacity or shovel count based on a container of known capacity. Mix water with the dry ingredients in sufficient amount to produce a workable mixture which will adhere to the vertical surfaces of the masonry units. Mortar that has stiffened because of loss of water through evaporation shall be retempered by adding water to restore the proper consistency and workability. Discard mortar that has reached its initial set or that has not been used within 2-1/2 hours.

3.10.6 Cutting and Fitting

Wherever possible, use full units in lieu of cut units. Where cut units are required to accommodate the design, cutting shall be done by masonry mechanics using power masonry saws. Wet-cut units shall be dried to the same surface-dry appearances of uncut units before being placed in the work. Cut edges shall be clean, true and sharp. Openings to accommodate pipes, conduits, and other accessories shall be neatly formed so that framing or escutcheons required will completely conceal the cut edges.

Insofar as practicable, all cutting and fitting shall be accomplished while masonry work is being erected.

3.10.7 Masonry Units

When being laid, masonry units shall have suction sufficient to hold the mortar and to absorb water from the mortar, but shall be damp enough to allow the mortar to remain in a plastic state to permit the unit to be leveled and plumbed immediately after being laid without destroying bond.

Masonry units with frogging shall be laid with the frog side down and better or face side exposed to view. Masonry units that are cored, recessed or otherwise deformed may be used in sills or in other areas except where deformations will be exposed to view.

3.10.8 Mortar Joints

Mortar joint widths shall be uniform and such that the specified widths are maintained throughout. Joints shall be of thickness equal to the difference between the actual and nominal dimensions of the masonry units in either height or length but in no case shall the joints be less than 1/4 inch nor more than 1/2 inch wide. Joints shall be tooled slightly concave. Tooling shall be accomplished when mortar is thumbprint hard and in a manner that will compress and seal the mortar joint and produce joints of straight and true lines free of tool marks.

3.10.9 Joint Reinforcement

Unless otherwise shown, space joint reinforcement at 16 inches on center vertically. Joint reinforcement shall not be placed in the same masonry course as veneer anchors unless the anchors are designed to accommodate the wire. Place joint reinforcement so that longitudinal wires are centered in the veneer wythe for solid units. Longitudinal wires shall be fully embedded in mortar for their entire length. Splices in joint reinforcement shall be lapped a minimum of 6 inches. Joint reinforcement shall be discontinuous at all veneer joints. The minimum cover for joint reinforcement is 5/8 inches.

3.10.10 Veneer Joints

Provide brick expansion joints at the locations shown on the drawings.

Details of joints shall be as indicated on the drawings. Joints shall be clean and free of mortar and shall contain only backer rod and sealant, installed in accordance with Section 07 92 00 JOINT SEALANTS. Horizontal reinforcement shall not extend through the joints.

3.10.11 Weep Holes

Provide weep holes at all flashing locations at intervals of 24 inches.

Place weep holes in head joints just above the flashing. Weep holes shall be formed by leaving head joints open or head joint vents may be used.

Keep weep holes free of mortar and other obstructions.

3.10.12 Head Joint Vents

Provide head joint vents near the top of the veneer wythe at the same spacing as the weep holes.

3.10.13 Discontinuous Work

When necessary to temporarily discontinue the work, step back the masonry for joining when work resumes. Toothing may be used only when specifically approved. Before resuming work, loose mortar shall be removed and the exposed joint shall be thoroughly cleaned. Top of walls subjected to rain or snow shall be covered with nonstaining waterproof covering or membrane when work is not in process. Covering shall extend a minimum of 2 feet down on each side of the wall and shall be held securely in place.

3.10.14 Cleaning

Completely remove mortar daubs or splashings from finished exposed masonry surfaces before they harden or set up. Before completion of the work, defects in mortar joints shall be raked out as necessary, filled with mortar, and tooled to match the adjacent existing mortar in the joints.

The proposed cleaning method shall be done on the sample wall panel and the sample panel shall be examined for discoloration or stain. If the sample panel is discolored or stained, change the method of cleaning to ensure that the masonry surfaces in the structure will not be adversely affected.

Masonry surfaces shall not be cleaned, other than removing excess surface mortar, until mortar in joints has hardened. Cleaning shall be accomplished with the use of stiff bristle fiber brushes, wooden paddles, wooden scrapers, or other suitable nonmetallic tools. The exposed brick surfaces shall be saturated with water and cleaned with a proprietary brick cleaning agent recommended by the clay products manufacturer. The cleaning agent shall not adversely affect the brick masonry surfaces. Proprietary cleaning agents shall be used in conformance with the cleaning product manufacturer's printed recommendations. Remove efflorescence or other stains in conformance with the recommendations of the masonry unit manufacturer. After construction and cleaning, masonry surfaces shall be left clean, free of mortar daubs, stain, and discolorations, including scum from cleaning operations, and will have tight mortar joints throughout.

Metallic tools and brushes shall not be used for cleaning.

3.11 BUILDING EXPANSION JOINTS

Locate expansion joints where indicated and made of the size and details shown.

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