Attachment 12 Specifications 7458 7600 and 7920.pdf

USDA BUILDING 157 ROOF REPAIR

SECTION 07548

ELASTOMERIC SHEET ROOFING

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. Use latest approved revision.

ASTM INTERNATIONAL (ASTM)

ASTM D 4434 Poly(Vinyl Chloride) Sheet Roofing

ASTM G 21 Determining Resistance of Synthetic Polymeric Materials to Fungi

FM GLOBAL (FM)

FM P7825a Approval Guide Fire Protection

FM P9513 Specialist Data Book Set for Roofing Contractors; contains 1-22 (2001), 1-28 (2002), 1-29 (2002), 1-28R/1-29R (1998), 1-30 (2000), 1-31 (2000), 1-32 (2000), 1-33 (2000), 1-34 (2001), 1-49 (2000), 1-52 (2000), 1-54 (2001)

SPRI (SPRI)

SPRI RP-4 Wind Design Standard for Ballasted Single-Ply Roofing Systems

UNDERWRITERS LABORATORIES (UL)

UL 580 Tests for Uplift Resistance of Roof Assemblies

UL 790 Test Methods for Fire Tests of Roof Coverings

1.2 SUBMITTALS

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

submittals not having a "G" designation are for Contractor Quality Control approval. When used, a designation following the "G" designation identifies the office that will review the submittal for the Government.

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PROCEDURES:

SD-02 Shop Drawings

Roofing System; G

Drawings showing arrangement of sheets, seam locations, and flashing details including waterproofing of joints where sheet metal flashings change direction. Shop drawings drawn by the manufacturer and certified by the Contractor for the specified system.

SD-03 Product Data

Installation

Manufacturer's instructions for preparing and installing the membrane, flashing, seams, insulation, nailers, and other accessories.

Inspection

The inspection procedure for substrate suitability including decks, curbs and insulation installation, prior to start of the work. Inspection procedures during and after placement of the membrane, and after completion of work by other trades.

SD-07 Certificates

Materials

Certificates of compliance attesting that the materials meet specification requirements. The certificates shall list the components required for the specified rating.

Qualifications

Contractor's qualifications as specified.

1.3 QUALITY ASSURANCE

1.3.1 Preliminary Roofing Conference

As soon as possible after award of single ply membrane roofing work, meet with Installer (Roofer), installers of substrate construction and other work adjoining roof system including penetrating work and roof accessories, Owner, and representatives of other entities directly concerned with performance of roofing system including (as applicable).

Review requirements (Contract Documents), submittals, status of coordinating work, availability of materials, and installation

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Michael.Kuennen Cross-Out facilities and establish preliminary installation schedule.

Review requirements for inspections, testing, certifications, forecasted weather conditions, governing regulations, insurance requirements, and proposed installation procedures.

Discuss roofing system protection requirements for construction period extending beyond roofing installation. Discuss possible need for temporary roofing.

1.4 GENERAL REQUIREMENTS

Thermoplastic Polyolefin (TPO) roofing shall be fully adhered to the roof surfaces indicated. Roofing membrane sheet widths shall be consistent with membrane attachment methods and wind uplift requirements, and shall be as large as practical to minimize joints. Membrane shall be free of defects and foreign material. Flashing work shall be coordinated to permit

SECTION 07548 Page 3 continuous roof-surfacing operations. Insulation shall be applied and weatherproofed on the same day.

1.4.1 Delivery and Storage

Materials shall be delivered to the jobsite in the manufacturer's original unopened packages, clearly marked with the manufacturer's name, brand name, description of contents, and label for compliance with UL requirements.

Time limited materials shall be used before shelf life expires. Materials other than roof pavers shall be stored in clean, dry areas. Storage temperatures shall be as specified by the manufacturer. A maximum of one day's supply of materials other than roof pavers may be stored on the roof when distributed so as not to exceed the roof live load limit. These materials shall be kept dry and clean until application. Roof pavers shall be stored uncovered, shall not be in contact with sod or earth, and shall not be stored on the roof.

1.4.2 Fire Resistance

The roofing system fire resistance shall be rated Class A as determined by UL 790 or Class 1 as determined by FM P7825a. Compliance of each component of the roofing system shall be evidenced by label or by written certification from the manufacturer.

1.4.3 Wind Uplift Requirements

Wind uplift resistance of the complete roof assembly shall be rated Class I-90 in accordance with FM P9513 or Class 90 in accordance with UL 580.

1.4.4 Warranty: G

Manufacturer's standard warranty for 15 years shall be furnished. Warranty shall provide for repair or replacement of the complete roofing system, including insulation and flashings, if leaking is caused by defects in materials or workmanship. Warranty includes responsibility for removal and replacement of other work which conceals membrane roofing. Manufacturer's warranty shall also include a minimum 80 mph wind warranty.

1.4.5 Qualifications

The Contractor shall submit documentation verifying that the Contractor has a minimum of 5 years experience with TPO roofing systems and has been certified by the TPO roofing manufacturer as an approved Installer for the specified TPO roofing system.

Installer's Field Supervision: Require Installer to maintain a full-time supervisor/foreman on job site during times that single ply roofing work is in progress and who is experienced in installation of roofing systems similar to type and scope required for this Project.

Manufacturer: The roofing system shall be manufactured by a roofing manufacturer with not less than ten (10) years experience of manufacturing the specified roof system. Manufactures of products shall be the primary manufacturer (private labeling of roofing products for other roofing manufacturers will not be considered). Obtain primary membrane roofing from a single manufacturer. Provide secondary materials as recommended by manufacturer of primary materials.

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PART 2 PRODUCTS

2.1 SOLVENTS AND SEALANTS

Adhesives, and sealants shall be as recommended by the membrane manufacturer. Adhesive: Low VOC type, less than 250 g/l.

2.2 FASTENERS

Fasteners for sheet-metal flashing shall be corrosion-resistant steel screws. Fasteners for anchoring the roofing membrane shall be as approved by the membrane manufacturer and identical to those used to obtain the wind uplift rating.

2.3 FLASHINGS

Flashings shall be ultra-violet resistant materials furnished by the membrane manufacturer, except as otherwise specified. Shaped flashing components shall be prefabricated. Sheared edges of metal flashings that will contact the membrane shall be turned into a tight hem.

2.4 MEMBRANE

Membrane: Provide all materials for a TPO (Thermoplastic Polyolefin), 60 mil sheet membrane roofing and flashing system by Carlisle Syntec, Elevate or GAF. Roofing system shall be approved Factory Mutual I-90 Windstorm Rated. Roofing shall provide U.L. Class A Fire Rating. Color: White.

2.5 PREFABRICATED ACCESSORIES

Pipe seals and expansion joint covers shall be types and sizes recommended by the membrane manufacturer.

2.6 MISCELLANEOUS MATERIALS

Sheet Seaming System: All seams and flashing to be hot-air welded utilizing membrane manufacturer's approved welding equipment.

Water Cut-off Mastic: Compatible with materials with which it is used, furnished by membrane manufacturer.

2.7 WALKWAYS

Concrete Pavers: 18" X 18" X 2" gray concrete placed according to attached roof drawing. Pavers shall have pads to protect the roof and allow water to drain under the pavers.

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PART 3 EXECUTION

3.1 ENVIRONMENTAL CONDITIONS

Membrane shall not be installed in high wind, inclement weather or when there is visible ice, frost or moisture on the deck or membrane. Unless otherwise specified by the manufacturer, membrane shall not be installed when air temperature is below 40 degrees F or within 5 degrees F of the dew point.

3.2 PREPARATION

The substrate of any bay or section of the building shall be complete and suitable for insulation and membrane installation before roofing is begun.

Insulation under roofing shall comply with Section 07220 ROOF AND DECK INSULATION. Surfaces on or against which membrane is applied shall be smooth, clean, and free from oil, grease, sharp edges, standing water, and construction debris. Joints over 1/4 inch wide shall be filled with foam backer rod and caulked.

3.3 INSTALLATION

Installation shall comply with the manufacturer's approved instructions except as otherwise specified.

3.3.1 Membrane

Unless otherwise specified by the manufacturer, the membrane shall be rolled out on the surface and allowed to relax for at least 1/2 hour when ambient temperature is 60 degrees F or higher or 2 hours when ambient temperature is below 60 degrees F prior to other installation activities.

Membrane shall be overlapped a minimum of 3 inches at sides and minimum 4 inches at ends. Direction of laps shall allow water to flow over and not into the lap. Membrane joints shall be free of wrinkles and fishmouths.

The entire length of joints shall be probe-tested and corrected during the day of installation. Defective areas shall be re-sealed. Wrinkles, fishmouths, or damaged areas shall be cut out and the area covered with membrane using a 3 inch seam on all sides. Repairs shall be probe-tested for continuity. Bonded areas of seams shall be a minimum 3 inches wide for bonded seams and 2 inches wide for heat-welded seams.

3.3.2 Fastening

Membrane shall be fastened to nailers in accordance with the membrane manufacturer's approved instructions. Unless otherwise specified, fasteners shall be staggered on 4 inch centers maximum; fasteners for sheet metal shall be staggered on 8 inch centers maximum; and a row of fasteners shall be at least 1/2 inch from edges of sheet metal.

3.3.3 Flashing

Roof edges, projections through the roof and changes in roof planes shall be flashed. The seam between the flashing and the membrane shall be completed before the flashing is bonded to vertical surfaces. The seam shall be sealed a minimum of 3 inches beyond the fasteners which attach the membrane to nailers. The installed flashings shall be secured at the top of the flashing a maximum of 12 inches on centers under the counterflashing or cap. Where possible, prefabricated components shall be used for pipe

SECTION 07548 Page 6 seals and flashing accessories.

3.3.4 Expansion Joints

Expansion joints shall be covered using Prefabricated covers or elastomeric flashing in accordance with the recommendations of the manufacturer.

3.3.5 Cutoffs

If work is terminated prior to weatherproofing the entire roof, the membrane shall be sealed to the roof deck. Flutes in metal decking shall be sealed off along the cutoff edge. Membrane shall be pulled free or cut to expose the insulation when resuming work and cut insulation sheets used for fill-in shall be removed. Asphalt or coal-tar products shall not be used for sealing.

3.6 INSPECTION

If non-destructive surveys by the Government indicate presence of wet insulation during the first 2 years after completion of the work, the Contractor shall take samples to verify the extent of the moisture, and shall replace wet insulation and the defective membrane.

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Michael.Kuennen Cross-Out

SECTION 07600

FLASHING AND SHEET METAL

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. Use the latest approved revision.

ASTM INTERNATIONAL (ASTM)

ASTM A 666 Annealed or Cold-Worked Austenitic Stainless Steel Sheet, Strip, Plate, and Flat Bar

ASTM B 209 Aluminum and Aluminum-Alloy Sheet and Plate

ASTM D 2822 Asphalt Roof Cement

ASTM E 154 Water Vapor Retarders Used in Contact with Earth Under Concrete Slabs, on Walls, or as Ground Cover

ORGANIZATION NAME (ACRONYM)

IDENTIFIER (date) Title

SHEET METAL AND AIR CONDITIONING CONTRACTORS' NATIONAL ASSOCIATION

(SMACNA)

SMACNA Arch. Manual Architectural Sheet Metal Manual

THE SOCIETY FOR PROTECTIVE COATINGS (SSPC)

SSPC Paint 12 Cold-Applied Asphalt Mastic (Extra Thick Film)

1.2 SUBMITTALS

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

submittals not having a "G" designation are for Contractor Quality Control approval. When used, a designation following the "G" designation identifies the office that will review the submittal for the Government.

SD-02 Shop Drawings

Sheet Metal; G

Shop drawings showing layout, profiles, methods of joining, and anchorages details.

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SD-04 Samples

Finish; G

1.3 SUMMARY

This Section includes the following:

Metal counter flashing.

Metal coping caps.

Scuppers.

Conductors Downspouts.

Miscellaneous sheet metal accessories.

1.4 GENERAL REQUIREMENTS

Sheet metalwork shall be accomplished to form weathertight construction without waves, warps, buckles, fastening stresses or distortion, and shall allow for expansion and contraction. Cutting, fitting, drilling, and other operations in connection with sheet metal required to accommodate the work of other trades shall be performed by sheet metal mechanics. Installation of sheet metal items used in conjunction with roofing shall be coordinated with roofing work to permit continuous roofing operations.

1.5 PROJECT CONDITIONS

Coordinate work of this section with interfacing and adjoining work for proper sequencing of each installation. Ensure best possible weather resistance and durability of work and protection of materials and finishes.

1.6 DELIVERY, HANDLING, AND STORAGE

Package and protect materials during shipment. Uncrate and inspect materials for damage, dampness, and wet-storage stains upon delivery to the job site. Remove from the site and replace damaged materials that cannot be restored to like-new condition. Handle sheet metal items to avoid damage to surfaces, edges, and ends. Store materials in dry, weather-tight, ventilated areas until immediately before installation.

PART 2 PRODUCTS

2.1 SHEET METAL FLASHING AND TRIM MATERIALS

2.1.1 Prefinished Sheet Metal:

2.1.1.1 Metal, 24 gauge.

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2.1.1.2 Finish

Primed and finished one side with fluoropolymer coating, containing 70 % polyvinylidene (PVF2) resin, 10. plus or minus 0.1 mil total dry film thickness. A wash coat, having a dry film thickness of 0.3 - 0.4 mils shall be applied to the unfinished side of the sheet metal. Kynar or equivalent.

2.1.1.3 Protection

Finished surfaces shall be protected with a strippable plastic film.

2.1.1.4 Color

White.

2.2 MISCELLANEOUS MATERIALS AND ACCESSORIES

2.2.1 Fasteners

Same metal as flashing/sheet metal or other non- corrosive metal as recommended by sheet manufacturer. Match finish of exposed heads with material being fastened.

2.2.2 Bituminous Coating

SSPC Paint 12, solvent-type bituminous mastic, nominally free of sulfur, compounded for 15-mil dry film thickness per coat.

2.2.3 Mastic Sealant

Polyisobutylene; nonhardening, nonskinning, non- drying, nonmigrating sealant.

2.2.4 Elastomeric Sealant

Generic type recommended by manufacturer of metal and fabricator of components being sealed and complying with requirements for joint sealants as specified in Division 7 Section "Joint Sealers".

2.2.5 Paper Slip Sheet

5-lb.rosin-sized building paper.

2.2.6 Polyethylene Underlayment

Minimum 6-mil carbonated polyethylene film resistant to decay when tested in accordance with ASTM E 154.

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2.2.7 Reglets

Metal or plastic units of type and profile indicated, compatible with flashing indicated, noncorrosive.

2.2.8 Metal Accessories

Provide sheet metal clips, straps, anchoring devices, continuous cleats, and similar accessory units as required for installation of work, matching or compatible with material being installed, noncorrosive, size and gage required for performance.

2.2.9 Roofing Cement

ASTM D 2822, asphaltic.

2.3 FABRICATION

2.3.1 General Metal Fabrication

Shop-fabricate work to greatest extent possible. Comply with details shown and with applicable requirements of SMACNA Arch. Manual and other recognized industry practices. Fabricate for waterproof and weather-resistant performance, with expansion provisions for running work, sufficient to permanently prevent leakage, damage, or deterioration of the work. Form work to fit substrates. Comply with material manufacturer instructions and recommendations for forming material. Form exposed sheet metal work without excessive oil-canning, buckling, and tool marks, true to line and levels indicated, with exposed edges folded back to form hems.

2.3.2 Seams

Fabricate nonmoving seams in sheet metal with flat-lock seams.

2.3.3 Expansion Provisions

Where lapped or bayonet-type expansion provisions in work cannot be used or would not be sufficiently water/weatherproof, form expansion joints of intermeshing hooked flanges, not less than 1 inch deep, filled with mastic sealant (concealed within joints). Provide for thermal expansion of all sheet metal work exceeding 15'-0" running length.

2.3.3.1 Spacing

10'-0" maximum, and located 2'-0" from corners and intersections.

2.3.4 Sealant Joints

Where movable, nonexpansion type joints are indicated or required for proper performance of work, form metal to provide for proper installation of elastomeric sealant, in compliance with SMACNA standards.

2.3.5 Separations

Provide for separation of metal from noncompatible metal or corrosive substrates by coating concealed surfaces at locations of contact, with bituminous coating or other permanent separation as recommended by manufacturer/fabricator.

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PART 3 EXECUTION

3.1 INSTALLATION REQUIREMENTS

3.1.1 General

Except as otherwise indicated, comply with manufacturer's installation instructions and recommendations and with SMACNA Arch. Manual. Anchor units of work securely in place by methods indicated, or if methods are not indicated on drawings, anchor units firmly in place with anchorage devices appropriate to the substrate. Space anchors to adequately resist lateral and thermal stresses as well as inward and outward pressures, but not more than 18 inches on center. Provide for thermal expansion of metal units.

Conceal fasteners where possible. Set units true to line and level as indicated. Install work with laps, joints, and seams that will be permanently watertight and weatherproof. Use continous cleats for installation of coping caps and fascias, etc.

3.1.2 Flashings

Flashing installed into reglets or saw cuts shall be secured with lead wedges or plugs spaced not to exceed 8 inches o.c. Completely fill saw cuts with sealant.

3.1.3 Underlayment

Where sheet metal is to be installed directly on cementitious or wood substrates, install a slip sheet of red rosin paper and a course of polyethylene underlayment.

3.1.4 Flanges

Bed flanges of work in a thick coat of bituminous roofing cement where required for waterproof performance.

3.2 CLEANING AND PROTECTION

3.2.1 Cleaning

Clean exposed metal surfaces, removing substances that might cause corrosion of metal or deterioration of finishes.

3.2.2 Protection

Advise Contractor of required procedures for surveillance and protection of flashings and sheet metal work during construction to ensure that work will be without damage or deterioration other than natural weathering at time of Substantial Completion.

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SECTION 07920

JOINT SEALANTS

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. Reference the latest approved revision.

ASTM INTERNATIONAL (ASTM)

ASTM C 509 Elastomeric Cellular Preformed Gasket and Sealing Material

ASTM C 570 Oil- and Resin-Base Caulking Compound for Building Construction

ASTM C 734 Low-Temperature Flexibility of Latex Sealants After Artificial Weathering

ASTM C 834 Latex Sealants

ASTM C 919 Use of Sealants in Acoustical Applications

ASTM C 920 Elastomeric Joint Sealants

ASTM D 1056 Flexible Cellular Materials - Sponge or Expanded Rubber

ASTM D 1667 Flexible Cellular Materials - Vinyl Chloride Polymers and Copolymers (Closed-Cell Foam)

ASTM D 217 Cone Penetration of Lubricating Grease

ASTM E 84 Surface Burning Characteristics of Building Materials

1.2 SUBMITTALS

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

submittals not having a "G" designation are for Contractor Quality Control approval. When used, a designation following the "G" designation identifies the office that will review the submittal for the Government.

SD-03 Product Data

Sealants; G

Primers

SECTION 07920 Page 1

Bond breakers

Backstops

Manufacturer's descriptive data including storage requirements, shelf life, curing time, instructions for mixing and application, and primer data (if required). A copy of the Material Safety Data Sheet shall be provided for each solvent, primer or sealant material.

SD-07 Certificates

Sealant

Certificates of compliance stating that the materials conform to the specified requirements.

1.3 ENVIRONMENTAL CONDITIONS

The ambient temperature shall be within the limits of 40 and 90 degrees F when sealant is applied.

1.4 QUALITY ASSURANCE

Preconstruction Compatibility and Adhesion Testing: Submit to joint sealant manufacturers samples of materials that will contact or affect joint sealants for compatibility and adhesion testing as indicated below including staining:

Use test methods standard with manufacturer to determine if priming and other specific joint preparation techniques are required to obtain rapid, optimum adhesion of joint sealants to joint substrates.

Perform tests under normal environmental conditions that will exist during actual installation.

Submit not less than 9 pieces of each type of material, including joint substrates, shims, joint sealant backings, secondary seals, and miscellaneous materials.

Schedule sufficient time for testing and analysis of results to prevent delay in the progress of the Work.

Investigate materials failing compatibility or adhesion tests, including staining tests, and obtain joint sealant manufacturer's written recommendations for corrective measures, including use of specially formulated primers.

Testing will not be required when joint sealant manufacturer is able to submit joint preparation data required above that are acceptable to Architect and are based on previous testing of current sealant products for adhesion to, and compatibility with, joint substrates and other materials matching those submitted.

1.5 DELIVERY AND STORAGE

Deliver materials to the job site in unopened manufacturers' external shipping containers, with brand names, date of manufacture, [color,] and

SECTION 07920 Page 2 material designation clearly marked thereon. Elastomeric sealant containers shall be labeled to identify type, class, grade, and use.

Carefully handle and store materials to prevent inclusion of foreign materials or subjection to sustained temperatures exceeding 90 degrees F or less than 0 degrees F.

PART 2 PRODUCTS

2.1 SEALANTS

Provide sealant that has been tested and found suitable for the substrates to which it will be applied.

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2.1.2 Exterior Sealant

For joints in vertical surfaces and none traffic horizontal surfaces, provide ASTM C 920, Type S or M, Grade NS, Class 25, Use NT. For joints in horizontal surfaces, provide ASTM C 920, Type S or M, Grade P, Class 25, Use T. Color:

Dow "Precast White" when used adjacent to items having a Bone White finish.

Products:

Silpruf; GE 790; Dow Spectrem 1 or 3; Tremco

2.1.4 Acoustical Sealant

Rubber or polymer-based acoustical sealant conforming to ASTM C 919 shall have a flame spread of 25 or less and a smoke developed rating of 50 or less when tested in accordance with ASTM E 84. Acoustical sealant shall have a consistency of 250 to 310 when tested in accordance with ASTM D 217, and shall remain flexible and adhesive after 500 hours of accelerated weathering as specified in ASTM C 734, and shall be non-staining.

2.1.5 Preformed Sealant

Preformed sealant shall be polybutylene or isoprene-butylene based pressure sensitive weather resistant tape or bead sealant capable of sealing out moisture, air and dust when installed as recommended by the manufacturer.

At temperatures from minus 30 to plus 160 degrees F, the sealant shall be non-bleeding and shall have no loss of adhesion.

2.1.5.1 Foam Strip

Foam strip shall be polyurethane foam. Foam strip shall be capable of sealing out moisture, air, and dust when installed and compressed as recommended by the manufacturer. Service temperature shall beminus 40 to plus 275 degrees F. Untreated strips shall be furnished with adhesive to hold them in place. Adhesive shall not stain or bleed into adjacent finishes. Treated strips shall be saturated with butylene waterproofing.

2.2 PRIMERS

Provide a nonstaining, quick-drying type and consistency recommended by the sealant manufacturer for the particular application.

2.3 BOND BREAKERS

Provide the type and consistency recommended by the sealant manufacturer to prevent adhesion of the sealant to backing or to bottom of the joint.

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2.4 BACKSTOPS

Provide neoprene, butyl, polyurethane, or polyethylene foams free from oil or other staining elements as recommended by sealant manufacturer. Backing shall be 25 to 33 percent oversize for closed cell and 40 to 50 percent oversize for open cell material, unless otherwise indicated. Backstop material shall be compatible with sealant. Do not use oakum and other types of absorptive materials as backstops.

2.4 CLEANING SOLVENTS

Provide type(s) recommended by the sealant manufacturer [except for aluminum and bronze surfaces that will be in contact with sealant].

PART 3 EXECUTION

3.1 SURFACE PREPARATION

Surfaces shall be clean, dry to the touch, and free from dirt frost, moisture, grease, oil, wax, lacquer, paint, or other foreign matter that would tend to destroy or impair adhesion. Oil and grease shall be removed with solvent and surfaces shall be wiped dry with clean cloths. When resealing an existing joint, remove existing calk or sealant prior to applying new sealant. For surface types not listed below, the sealant manufacturer shall be contacted for specific recommendations.

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3.2 SEALANT PREPARATION

Do not add liquids, solvents, or powders to the sealant. Mix multicomponent elastomeric sealants in accordance with manufacturer's instructions.

3.3 APPLICATION

3.3.1 Joint Width-To-Depth Ratios

a. Acceptable Ratios:

JOINT WIDTH JOINT DEPTH

Minimum Maximum

For metal, glass, or other nonporous surfaces:

1/4 inch (minimum) 1/4 inch 1/4 inch over 1/4 inch 1/2 of Equal to width width

For wood, concrete, masonry, stone:

1/4 inch (minimum) 1/4 inch 1/4 inch Over 1/4 inch to 1/2 inch 1/4 inch Equal to width

Over 1/2 inch to 2 inches 1/2 inch 5/8 inch Over 2 inches (As recommended by sealant manufacturer)

b. Unacceptable Ratios: Where joints of acceptable width-to-depth ratios have not been provided, clean out joints to acceptable depths and grind or cut to acceptable widths without damage to the adjoining work. Grinding shall not be required on metal surfaces.

3.3.2 Masking Tape

Masking tape shall be placed on the finish surface on one or both sides of a joint cavity to protect adjacent finish surfaces from primer or sealant smears. Masking tape shall be removed within 10 minutes after joint has been filled and tooled.

3.3.3 Backstops

Install backstops dry and free of tears or holes. Tightly pack the back or bottom of joint cavities with backstop material to provide a joint of the depth specified. Install backstops in the following locations:

a. Where indicated.

b. Where backstop is not indicated but joint cavities exceed the acceptable maximum depths specified in paragraph entitled, "Joint Width-to-Depth Ratios."

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3.3.4 Primer

Immediately prior to application of the sealant, clean out loose particles from joints. Where recommended by sealant manufacturer, apply primer to joints in concrete masonry units, wood, and other porous surfaces in accordance with sealant manufacturer's instructions. Do not apply primer to exposed finish surfaces.

3.3.5 Bond Breaker

Provide bond breakers to the back or bottom of joint cavities, as recommended by the sealant manufacturer for each type of joint and sealant used, to prevent sealant from adhering to these surfaces. Carefully apply the bond breaker to avoid contamination of adjoining surfaces or breaking bond with surfaces other than those covered by the bond breaker.

3.3.6 Sealants

Provide a sealant compatible with the material(s) to which it is applied.

Do not use a sealant that has exceeded shelf life or has jelled and can not be discharged in a continuous flow from the gun. Apply the sealant in accordance with the manufacturer's instructions with a gun having a nozzle that fits the joint width. Force sealant into joints to fill the joints solidly without air pockets. Tool sealant after application to ensure adhesion. Sealant shall be uniformly smooth and free of wrinkles. Upon completion of sealant application, roughen partially filled or unfilled joints, apply sealant, and tool smooth as specified. Sealer shall be applied over the sealant when and as specified by the sealant manufacturer.

3.4 PROTECTION AND CLEANING

3.4.1 Protection

Protect areas adjacent to joints from sealant smears. Masking tape may be used for this purpose if removed 5 to 10 minutes after the joint is filled.

3.4.2 Final Cleaning

Upon completion of sealant application, remove remaining smears and stains and leave the work in a clean and neat condition.

a. Masonry and Other Porous Surfaces: Immediately scrape off fresh sealant that has been smeared on masonry and rub clean with a solvent as recommended by the sealant manufacturer. Allow excess sealant to cure for 24 hour then remove by wire brushing or sanding.

b. Metal and Other Non-Porous Surfaces: Remove excess sealant with a solvent-moistened cloth.

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2.1.2 Stainless Steel Sheet