04 21 13.pdf

SABER Solicitation FA2517-08-R-5002

04 21 13-1 05/08/09

SECTION 04 21 13

NONBEARING MASONRY VENEER/STEEL STUD WALLS

PART 1 GENERAL

1.1 REFERENCES

1.1.1 The publications listed below form a part of this specification to the extent referenced. The publications are referred to in the text by the basic designation only. Unless otherwise noted, the latest published version and/or revision shall be used.

1.1.1.1 AMERICAN INSTITUTE OF STEEL CONSTRUCTION (AISC)

a. AISC 325 Manual of Steel Construction

1.1.1.2 AMERICAN IRON AND STEEL INSTITUTE (AISI)

a. AISI SG-971-Spec Specification and Commentary for the Design of Cold-Formed

Steel Structural Members and Commentary

1.1.1.3 AMERICAN SOCIETY OF HEATING, REFRIGERATING AND AIR-CONDITIONING

ENGINEERS (ASHRAE)

a. ASHRAE FUN IP Fundamentals Handbook, I-P Edition

1.1.1.4 AMERICAN WELDING SOCIETY (AWS)

a. AWS D1.3 Structural Welding Code - Sheet Steel

1.1.1.5 APA - THE ENGINEERED WOOD ASSOCIATION (APA)

a. APA PS 1 Voluntary Product Standard for Construction and Industrial

Plywood

1.1.1.6 ASTM INTERNATIONAL (ASTM)

a. ASTM A 123 Standard Specification for Zinc (Hot-Dip Galvanized) Coatings on Iron and Steel Products

b. ASTM A 153 Standard Specification for Zinc Coating (Hot-Dip) on Iron and

Steel Hardware

c. ASTM A 36 Standard Specification for Carbon Structural Steel

d. ASTM A 653 Standard Specification for Steel Sheet, Zinc-Coated (Galvanized) or Zinc-Iron Alloy-Coated (Galvannealed) by the Hot-Dip

Process

e. ASTM A 82 Standard Specification for Steel Wire, Plain, for Concrete

Reinforcement

f. ASTM C 1002 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

g. ASTM C 1072 Standard Test Method for Measurement of Masonry Flexural

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Bond Strength

h. ASTM C 216 Facing Brick (Solid Masonry Units Made from Clay or Shale)

i. ASTM C 270 Standard Specification for Mortar for Unit Masonry

j. ASTM C 494 Standard Specification for Chemical Admixtures for Concrete

k. ASTM C 578 Standard Specification for Rigid, Cellular Polystyrene Thermal

Insulation

l. ASTM C 591 Standard Specification for Unfaced Preformed Rigid Cellular

Polyisocyanurate Thermal Insulation

m. ASTM C 665 Mineral-Fiber Blanket Thermal Insulation for Light Frame

Construction and Manufactured Housing

n. ASTM C 67 Standard Test Methods for Sampling and Testing Brick and

Structural Clay Tile

o. ASTM C 744 Prefaced Concrete and Calcium Silicate Masonry Units

p. ASTM C 780 Preconstruction and Construction Evaluation of Mortars for Plain and Reinforced Unit Masonry

q. ASTM C 90 Loadbearing Concrete Masonry Units

r. ASTM C 955 Load-Bearing (Transverse and Axial) Steel Studs, Runners

(Tracks), and Bracing or Bridging for Screw Application of

Gypsum Panel Products and Metal Plaster Bases

s. ASTM D 1056 Standard Specification for Flexible Cellular Materials - Sponge or Expanded Rubber

t. ASTM D 1330 Rubber Sheet Gaskets

u. ASTM D 1667 Flexible Cellular Materials - Poly (Vinyl Chloride) Foam

(Closed-Cell)

v. ASTM D 2103 Standard Specification for Polyethylene Film and Sheeting

w. ASTM D 226 Standard Specification for Asphalt-Saturated Organic Felt Used in Roofing and Waterproofing

1.2 SUBMITTALS

1.2.1 Government approval may be required on any of the following items. Items requiring submittals will be listed on the Submittal Register. Provide copies of all submittals per the requirements in

Section 01 33 00, Submittal Procedures, or as listed on the Submittal Register.

1.2.1.1 SD-02 Shop Drawings

a. Detail Drawings

(1) Detail drawings as specified.

1.2.1.2 SD-04 Samples

a. Expansion Joint Materials

b. Clay Brick

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c. Concrete Masonry Unit

d. Prefaced Concrete Masonry Unit

e. Sample Panel

(1) A portable panel, approximately 2 by 2 feet, to establish the range of color and texture.

One of each type of masonry veneer anchor used.

1.2.1.3 SD-06 Test Reports

a. Calculations

(1) Calculations demonstrating the structural adequacy of steel lintels and shelf angles 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.

1.2.1.4 SD-07 Certificates

a. Clay Brick

b. Concrete Masonry Unit

c. Joint Reinforcement

d. Expansion Joint Materials

e. Insulation

f. Exterior Sheathing

g. Moisture Barrier

h. Vapor Retarder

i. Veneer Anchors

j. Welding

(1) 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 SAMPLE PANEL

1.3.1 After the material samples are approved and prior to starting masonry work, a sample masonry panel shall be built on the project site where directed. The sample panel shall be not less than 6 feet long by 4 feet high. The panel shall be 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. The approved sample panel shall be used as a standard of workmanship required in the actual installation. The sample

04 21 13-4 05/08/09 panel shall be protected from weather and construction operations and shall not be removed until the masonry veneer/steel stud wall work has been completed and accepted.

1.4 DELIVERY, HANDLING AND STORAGE

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

Cementitious materials shall be stored in dry, weather-tight enclosures or covers. Sand and other aggregates shall be stored 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. Insulation, moisture barrier, and gypsum sheathing shall be stored 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.

1.5 EFFLORESCENCE TESTS

1.5.1 Efflorescence tests shall be performed by an approved commercial testing laboratory. Sampling for the tests shall be the responsibility of the Contractor. Brick shall be sampled and tested for efflorescence in accordance with ASTM C 67 and the rating shall be: "not effloresced".

1.6 DETAIL DRAWINGS

1.6.1 The Contractor shall 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.

PART 2 PRODUCTS

2.1 VENEER WYTHE

2.1.1 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.

2.1.2 Clay Brick

2.1.2.1 Clay brick veneer shall be masonry units conforming to ASTM C 216, Type FBS. Color range and texture shall be as indicated and shall conform to the approved sample. Grade SW shall be used for all brickwork. Brick unit sizes shall be modular unless indicated otherwise.

2.1.3 Concrete Masonry Unit

2.1.3.1 Concrete masonry unit veneer shall be solid and conform to ASTM C 90. Architectural type, color range and texture shall be as indicated and shall conform to the approved sample.

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Masonry unit sizes shall be modular.

2.1.4 Prefaced Concrete Masonry Unit

2.1.4.1 Prefaced concrete masonry unit veneer shall conform to ASTM C 744 using masonry units conforming to ASTM C 90. Prefaced concrete unit facing shall turn over the edges and ends of the unit at least 3/8 inch in the direction of the thickness of the unit to form a lip at least 1/16 inch thick. Variation in color and texture shall not exceed that of the approved samples.

Masonry unit sizes shall be modular.

2.2 MORTAR

2.2.1 Mortar shall conform 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. Aggregates shall be from one source.

2.2.2 Masonry Cement

2.2.2.1 Masonry cement in conformance with ASTM C 91 may be used in the mortar. When using a masonry cement a comparative test shall be performed between a Portland cement-lime mortar and the masonry cement mortar proposed for the project to evaluate the ASTM C 1072 bond and the ASTM C 780 compressive strength of the two mixes. The test shall be conducted with the proposed masonry units for the project. The masonry cement mortar will be acceptable if the bond and compressive strength values are equal to or higher than the portland cement-lime mix. The air-content of the masonry cement shall be limited to 12 percent maximum.

2.2.3 Admixtures

2.2.3.1 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, Type C.

2.3 JOINT REINFORCEMENT

2.3.1 Joint reinforcement shall be of steel wire conforming to ASTM A 82. Fabrication shall be by welding. Tack welding will not be permitted. Reinforcement shall be zinc-coated after fabrication in accordance with ASTM A 153, 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

2.4.1 Cold-formed framing shall consist 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 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. Metal framing for interior partitions are specified in Section 09 22 00 Metal Support Assemblies.

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2.4.2 Steel Studs

2.4.2.1 Studs shall be furnished as shown in the contract drawings.

2.4.3 Runners, Tracks, Bridging and Accessories

2.4.3.1 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 Grade 33 having a minimum yield strength of 33,000 psi.

2.5 INSULATION

2.5.1 The Contractor shall comply with EPA requirements in accordance with Section 01 62 35

Recycled / Recovered Materials.

2.5.2 Blanket Insulation

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

2.5.3 Rigid Board-Type Insulation

2.5.3.1 Insulation for wall cavities shall be rigid board-type insulation. Rigid board-type insulation shall be either polystyrene 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.

2.6 GYPSUM WALLBOARD

2.6.1 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

2.7.1 Gypsum or Plywood sheathing that is installed on the exterior side of the cold-formed steel framing system shall have a minimum thickness of 1/2 inch and shall be 4 feet wide. Gypsum sheathing shall conform to ASTM C 79. Gypsum sheathing shall have a water-resistant gypsum core with a water-repellent paper firmly bonded to the core. Plywood sheathing shall be in accordance with APA PS 1, grade C-D with exterior glue.

2.8 MOISTURE PROTECTION

2.8.1 Moisture Barrier

2.8.2 The moisture barrier shall be 15-lb asphalt-saturated felt conforming to ASTM D 226 Type I (No.

15).

2.8.3 Vapor Retarder

2.8.3.1 The vapor retarder shall be polyethylene film conforming to ASTM D 2103, 6 mil minimum

04 21 13-7 05/08/09 thickness.

2.8.4 Staples

2.8.4.1 Staples for attaching the moisture barrier to the exterior sheathing shall be the type and size best suited to provide a secure connection. Staples shall be made from either galvanized steel or stainless steel wire.

2.8.5 Joint Tape

2.8.5.1 Tape for sealing the joints in the vapor retarder shall be laminated tape with pressure sensitive adhesive as recommended by the manufacturer of the polyethylene film.

2.9 VENEER ANCHORS

2.9.1 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 designed for the design loadings shown. Anchors shall transfer the design loadings from the masonry veneer to the cold-formed steel framing system or other support without exceeding the allowable stresses and deflections in the anchors. Length of anchor wires shall be such that the outermost wires lie between 1-1/4 inch from each face of the masonry veneer. Anchors wires shall not have drips. Wires for veneer anchors shall be rectangular or triangular hoops formed from 3/16 inch diameter steel wire conforming to ASTM A 82. Anchor assemblies including wires and anchor plates shall be hot-dip galvanized conforming to ASTM A 153 Class B-2. The veneer anchor shall have a minimum capacity of 200 pounds. In the direction perpendicular to the masonry veneer, the anchor assembly shall have a maximum play of 1/16 inch.

2.9.2 Adjustable Pintle-Eye Type Wire Anchors

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

2.9.3 Dovetail Anchors

2.9.3.1 Dovetail slots are specified in Section 03 30 00 Cast-In-Place Concrete.

2.10 CONNECTIONS

2.10.1 Screws, bolts and anchors shall be hot-dip galvanized in accordance with ASTM A 123 or ASTM

A 153 as appropriate.

2.10.2 Framing Screws, Bolts and Anchors

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

2.10.3 Welding

2.10.3.1 Welded connections shall be designed and all welding shall be performed in accordance with

AWS D1.3, as modified by AISI SG-971-Spec. Welders shall be qualified in accordance with

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AWS D1.3. All welds shall be cleaned and touched-up with zinc-rich paint.

2.10.4 Veneer Anchor Screws

2.10.4.1 Screws for attachment of the veneer anchors to the cold-formed steel framing members shall be

No. 12 minimum. Screws shall be shown on the detail drawings. The length of screws shall be such that the screws penetrate the holding member by not less than 5/8 inch.

2.10.5 Gypsum Sheathing Screws

2.10.5.1 Screws for attachment of gypsum sheathing to cold-formed steel framing shall conform to

ASTM C 1002, Type S.

2.11 SYNTHETIC RUBBER WASHERS

2.11.1 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

2.12.1 Expansion joint materials shall be bellows or U-shaped type conforming to Section 07 60 00

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

2.13.1 Copper or stainless steel flashing shall conform to the requirements in Section 07 60 00 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 AND SHELF ANGLES

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

2.15 CAULKING AND SEALANTS

2.15.1 Caulking and sealants shall be as specified in Section 07 92 00 Joint Sealants.

PART 3 EXECUTION

3.1 GENERAL INSTALLATION REQUIREMENTS

3.1.1 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.

The Contractor shall submit Calculations as specified in the Submittals paragraph.

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3.2 STEEL STUD WALL FRAMING

3.2.1 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 detailed drawings. Horizontal bridging shall be provided as necessary.

Studs shall be spaced 16 inches on center unless otherwise indicated on the drawings. Coordinate stud spacing with sheathing and anchor requirements. At wall openings for doors, windows and other similar features, the framing system shall provide for the installation and anchorage of the required subframes or finish frames. Steel frames shall be securely attached through built-in anchors to the nearest stud on each side of the opening with self-drilling screws. Double studs shall be provided at both jambs of all door openings. Door frames and other built-in items shall be grouted solid.

3.3 STEEL SHELF ANGLES

3.3.1 Unless otherwise shown, steel shelf angles shall be provided in segments that do not exceed 10 feet in length. At building corners, shelf angle segments shall be mitered and securely attached together by welding with legs no less than 4 feet where possible. Shelf angle segments shall not be connected together but instead shall be installed with 1/4 inch wide gaps between the segments. Fabrication and erection tolerances shall be in accordance with the AISC Code of

Standard Practice, as indicated in AISC 325.

3.4 INSULATION

3.4.1 The actual installed thickness of insulation shall provide a maximum thermal R of 19 for the completed exterior wall construction as determined in accordance with ASHRAE FUN IP, unless shown differently 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. Insulation shall be installed 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, insulation shall be placed on the dry side of the item away from excessive humidity.

3.5 GYPSUM WALLBOARD

3.5.1 Gypsum wallboard shall be installed on the interior face of the cold-formed steel framing system.

Installation shall be as specified in Section 09 29 00 Gypsum Board except at vertical slip joints, the gypsum wallboard shall be connected to the vertical studs to prevent movement at the slip joint.

3.6 EXTERIOR SHEATHING

3.6.1 Sheathing shall be installed on the exterior face of the cold-formed steel framing system with self-drilling screws. Screws shall be located a minimum of 3/8 inch from the ends and edges of sheathing panels and shall be 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

04 21 13-10 05/08/09 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.

3.7 MOISTURE PROTECTION

3.7.1 Moisture Barrier

3.7.1.1 The asphalt-saturated felt or other approved moisture barrier shall be installed on the outer face of the exterior sheathing. The moisture barrier shall be installed horizontally and shingled with each sheet lapped not less than 6 inches over the sheet below. Vertical end joints shall be lapped not less than 6 inches and shall be staggered. Attachment of the moisture barrier shall be with staples spaced not greater than 16 inches on center or as required by the manufacturer.

3.7.2 Vapor Retarder

3.7.2.1 A vapor retarder shall be installed between the steel studs and the gypsum wall board. The vapor retarder shall be installed in accordance with the manufacturer's recommendations to form a complete retarder to vapor infiltration. The joints shall be lapped and sealed with tape.

3.8 VENEER ANCHORS

3.8.1 Veneer anchors shall be attached with screws through the sheathing and rigid insulation to the steel studs or other 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. Veneer anchors shall be installed with the outermost wires lying between

5/8 inch from each face of the masonry veneer. Synthetic rubber washers shall be used between the anchor connector plates and the moisture barrier. A clutch torque slip screw gun shall be used 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 steel studs and other supports with a maximum spacing of 24 inches on center. Dovetail slots shall be installed as specified in the Section 03 30 00 Cast-In-Place Concrete.

3.9 FLASHING

3.9.1 Continuous flashing shall be provided 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 60 00

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.

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3.10 MASONRY VENEER

3.10.1 Exterior masonry wythes shall be constructed to the thickness indicated on the drawings. A cavity consisting of a one 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 on the cold-formed steel framing system. Extreme care shall be taken 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.

Longitudinal reinforcement consisting of at least one continuous galvanized steel wire shall be placed in the veneer wythe. The minimum wire size shall be 9 gauge. 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 re-laid. Mortar which protrudes more than 1/2 inch into the cavity space shall be removed. Means shall be provided 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.

3.10.2 Surface Preparation

3.10.2.1 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.

3.10.3 Hot Weather Construction

3.10.3.1 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.

3.10.4 Cold Weather Construction

3.10.4.1 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. The proposed method of maintaining the temperature within the specified range shall be submitted for approval prior to implementation. No units shall be laid on a surface having a film of frost or water.

3.10.5 Tolerances

3.10.5.1 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.

a. TABLE 1

Variation From Plumb

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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

3.10.6 Mixing of Mortar

3.10.6.1 Mortar shall be mixed 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. Water shall be mixed with the dry ingredients in sufficient amount to provide 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. Mortar that has reached its initial set or that has not been used within 2-1/2 hours shall be discarded.

3.10.7 Cutting and Fitting

3.10.7.1 Wherever possible, full units shall be used 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.

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3.10.8 Masonry Units

3.10.8.1 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 that are cored, recessed or otherwise deformed may be used in sills or in other areas except where deformations will be exposed to view.

3.10.9 Mortar Joints

3.10.9.1 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 neither 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.

3.10.10 Joint Reinforcement

3.10.10.1 Unless otherwise shown, joint reinforcement shall be spaced 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. Joint reinforcement shall be placed 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 must be discontinuous at all veneer joints. The minimum cover for joint reinforcement is 5/8 inches.

3.10.11 Veneer Joints

3.10.11.1 Brick expansion joints and concrete masonry veneer joints shall be provided 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.

3.10.12 Weep Holes

3.10.12.1 Weep holes shall be provided at all flashing locations at intervals of 24 inches. Weep holes shall be placed in head joints just above the flashing. Weep holes shall be formed by leaving head joints open or head joint vents may be used. Weep holes shall be kept free of mortar and other obstructions.

3.10.13 Head Joint Vents

3.10.13.1 Head joint vents shall be provided near the top of the veneer wythe at the same spacing as the weep holes.

3.10.14 Discontinuous Work

3.10.14.1 When necessary to temporarily discontinue the work, masonry shall be stepped back for joining

04 21 13-14 05/08/09 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.

3.10.15 Cleaning

3.10.15.1 Mortar daubs or splashings shall be completely removed 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, the method of cleaning shall be changed 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. Concrete masonry unit surfaces shall be dry-brushed at the end of each day's work after any required pointing has been done. Efflorescence or other stains shall be removed 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

3.11.1 Expansion joints shall be located where indicated and shall be of the size and details shown.

END OF SECTION 04 21 13