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HomeMy WebLinkAbout07 54 19 Polyvinyl-Chloride (PVC) RoofingTHE KENT 07 54 19 - THE KENT Issue Date 05.09.18 PVC ROOFING THE KENT SECTION 07 54 19 - POLYVINYL-CHLORIDE (PVC) ROOFING PART 1 - GENERAL 1.1 RELATED DOCUMENTS A. Drawings and general provisions of the Contract, including General and Supplementary Conditions and Division 01 Specification Sections, apply to this Section. 1.2 SUMMARY A. Section Includes: 1. Adhered polyvinyl chloride (PVC) roofing system. 2. Substrate board. 3. Vapor retarder. 4. Roof insulation. 5. Cover board. 6. Walkways. B. Section includes installation of sound-absorbing insulation strips in ribs of roof deck. Sound- absorbing insulation strips are furnished under Section 05 31 00 "Steel Decking." C. Related Requirements: 1. Section 06 10 00 "Rough Carpentry" for wood nailers, curbs, and blocking; and for wood- based, structural-use roof deck panels. 2. Section 06 16 00 "Sheathing" for wood-based, structural-use roof deck panels. 3. Section 07 21 00 "Thermal Insulation" for insulation beneath the roof deck. 4. Section 07 62 00 "Sheet Metal Flashing and Trim" for metal roof flashings, counter flashings and roof drains. 5. Section 07 71 00 "Roof Specialties" for pre-manufactured copings and roof edge flashings. 6. Section 07 95 00 "Expansion Joints" for roof expansion-joint assemblies. 7. Section 07 92 00 "Joint Sealants" for joint sealants, joint fillers, and joint preparation. 8. Division 22 "Storm Drainage Piping Specialties" for roof drains. 1.3 DEFINITIONS A. Roofing Terminology: Definitions in ASTM D 1079 and glossary in NRCA's "The NRCA Roofing Manual: Membrane Roof Systems" apply to work of this Section. 1.4 PRE-INSTALLATION MEETINGS A. Preliminary Roofing Conference: Before starting roof deck construction, conduct conference at Project site. THE KENT 07 54 19 - THE KENT Issue Date 05.09.18 PVC ROOFING THE KENT 1. Meet with Owner, Architect, Construction Manager, Owner's insurer if applicable, testing and inspecting agency representative, roofing Installer, roofing system manufacturer's representative, deck Installer, air barrier Installer, and installers whose work interfaces with or affects roofing, including installers of roof accessories and roof-mounted equipment. 2. Review methods and procedures related to roofing installation, including manufacturer's written instructions. 3. Review and finalize construction schedule, and verify availability of materials, Installer's personnel, equipment, and facilities needed to make progress and avoid delays. 4. Review deck substrate requirements for conditions and finishes, including flatness and fastening. 5. Review structural loading limitations of roof deck during and after roofing. 6. Review base flashings, special roofing details, roof drainage, roof penetrations, equipment curbs, and condition of other construction that affects roofing system. 7. Review governing regulations and requirements for insurance and certificates if applicable. 8. Review temporary protection requirements for roofing system during and after installation. 9. Review roof observation and repair procedures after roofing installation. B. Pre-installation Roofing Conference: Conduct conference at Project site. 1. Meet with Owner, Architect, Construction Manager, Owner's insurer if applicable, testing and inspecting agency representative, roofing Installer, roofing system manufacturer's representative, deck Installer, air barrier Installer, and installers whose work interfaces with or affects roofing, including installers of roof accessories and roof-mounted equipment. 2. Review methods and procedures related to roofing installation, including manufacturer's written instructions. 3. Review and finalize construction schedule, and verify availability of materials, Installer's personnel, equipment, and facilities needed to make progress and avoid delays. 4. Examine deck substrate conditions and finishes for compliance with requirements, including flatness and fastening. 5. Review structural loading limitations of roof deck during and after roofing. 6. Review base flashings, special roofing details, roof drainage, roof penetrations, equipment curbs, and condition of other construction that affects roofing system. 7. Review governing regulations and requirements for insurance and certificates if applicable. 8. Review temporary protection requirements for roofing system during and after installation. 9. Review roof observation and repair procedures after roofing installation. 1.5 ACTION SUBMITTALS A. Product Data: For each type of product. 1. For insulation and roof system component fasteners, include copy of FM Approvals' RoofNav listing. B. Shop Drawings: Include roof plans, sections, details, and attachments to other work, including the following: 1. Layout and thickness of insulation. THE KENT 07 54 19 - THE KENT Issue Date 05.09.18 PVC ROOFING THE KENT 2. Base flashings and membrane terminations. 3. Flashing details at penetrations. 4. Tapered insulation thickness and slopes. 5. Roof plan showing orientation of steel roof deck and orientation of roof membrane, fastening spacings, and patterns for mechanically fastened roofing system. 6. Insulation fastening patterns for corner, perimeter, and field-of-roof locations. 7. Tie-in with air barrier. C. Samples for Verification: For the following products: 1. Roof membrane and flashing, of color required. 2. Aggregate surfacing material in gradation and color required. 3. Roof paver, full sized, in each color and texture required. 4. Walkway pads or rolls, of color required. D. Wind Uplift Resistance Submittal: For roofing system, indicating compliance with wind uplift performance requirements. 1.6 INFORMATIONAL SUBMITTALS A. Qualification Data: For Installer and manufacturer. 1. Refer also to Specification Section 01 40 00 “Quality Requirements.” B. Manufacturer Certificates: 1. Performance Requirement Certificate: Signed by roof membrane manufacturer, certifying that roofing system complies with requirements specified in "Performance Requirements" Article. a. Submit evidence of compliance with performance requirements. 2. Special Warranty Certificate: Signed by roof membrane manufacturer, certifying that all materials supplied under this Section are acceptable for special warranty. C. Product Test Reports: For roof membrane and insulation, tests performed by independent qualified testing agency indicating compliance with specified requirements. D. Evaluation Reports: For components of roofing system, from ICC-ES. E. Field Test Reports: 1. Concrete internal relative humidity test reports. 2. Fastener-pullout test results and manufacturer's revised requirements for fastener patterns. F. Field quality-control reports. G. Sample Warranties: For manufacturer's special warranties. 1.7 CLOSEOUT SUBMITTALS A. Maintenance Data: For roofing system to include in maintenance manuals. THE KENT 07 54 19 - THE KENT Issue Date 05.09.18 PVC ROOFING THE KENT B. Certified statement from existing roof membrane manufacturer stating that existing roof warranty has not been affected by Work performed under this Section. 1.8 QUALITY ASSURANCE A. Manufacturer Qualifications: A qualified manufacturer that is UL listed in FM Approvals' RoofNav for roofing system identical to that used for this Project. 1. Refer also to Specification Section 01 40 00 “Quality Requirements.” B. Installer Qualifications: A qualified firm that is approved, authorized, or licensed by roofing system manufacturer to install manufacturer's product and that is eligible to receive manufacturer's special warranty. 1. Refer also to Specification Section 01 40 00 “Quality Requirements.” 1.9 DELIVERY, STORAGE, AND HANDLING A. Deliver roofing materials to Project site in original containers with seals unbroken and labeled with manufacturer's name, product brand name and type, date of manufacture, approval or listing agency markings, and directions for storing and mixing with other components. B. Store liquid materials in their original undamaged containers in a clean, dry, protected location and within the temperature range required by roofing system manufacturer. Protect stored liquid material from direct sunlight. 1. Discard and legally dispose of liquid material that cannot be applied within its stated shelf life. C. Protect roof insulation materials from physical damage and from deterioration by sunlight, moisture, soiling, and other sources. Store in a dry location. Comply with insulation manufacturer's written instructions for handling, storing, and protecting during installation. D. Handle and store roofing materials, and place equipment in a manner to avoid permanent deflection of deck. 1.10 FIELD CONDITIONS A. Weather Limitations: Proceed with installation only when existing and forecasted weather conditions permit roofing system to be installed according to manufacturer's written instructions and warranty requirements. 1.11 WARRANTY A. Special Warranty: Manufacturer agrees to repair or replace components of roofing system that fail in materials or workmanship within specified warranty period. 1. Special warranty includes roof membrane, base flashings, roof insulation, fasteners, cover boards, substrate board, roof pavers, and other components of roofing system. 2. Warranty Period: 10 years from date of Substantial Completion. THE KENT 07 54 19 - THE KENT Issue Date 05.09.18 PVC ROOFING THE KENT PART 2 - PRODUCTS 2.1 PERFORMANCE REQUIREMENTS A. General Performance: Installed roofing and base flashings shall withstand specified uplift pressures, thermally induced movement, and exposure to weather without failure due to defective manufacture, fabrication, installation, or other defects in construction. Roof system and flashings shall remain watertight. 1. Accelerated Weathering: Roof membrane shall withstand 2000 hours of exposure when tested according to ASTM G 152, ASTM G 154, or ASTM G 155. 2. Impact Resistance: Roof membrane shall resist impact damage when tested according to ASTM D 3746, ASTM D 4272, or the "Resistance to Foot Traffic Test" in FM Approvals 4470. B. Material Compatibility: Roofing materials shall be compatible with one another and adjacent materials under conditions of service and application required, as demonstrated by roof membrane manufacturer based on testing and field experience. C. Wind Uplift Resistance: Design roofing system to resist the wind uplift pressures when tested according to FM Approvals 4474, UL 580, or UL 1897. 1. Refer also to Structural Drawings General Notes. D. FM Approvals' RoofNav Listing: Roof membrane, base flashings, and component materials shall comply with requirements in FM Approvals 4450 or FM Approvals 4470 as part of a roofing system and shall be listed in FM Approvals' RoofNav for Class 1 or noncombustible construction, as applicable. Identify materials with FM Approvals Certification markings. 1. Fire/Windstorm Classification: Class 1A-120. 2. Hail-Resistance Rating: SH. E. Solar Reflectance Index: Not less than 78 when calculated according to ASTM E 1980, based on testing identical products by a qualified testing agency. F. ENERGY STAR Listing: Roofing system shall be listed on the DOE's ENERGY STAR "Roof Products Qualified Product List" for low-slope roof products. G. Energy Performance: Roofing system shall have an initial solar reflectance of not less than 0.70 and an emissivity of not less than 0.75 when tested according to CRRC-1. H. Exterior Fire-Test Exposure: ASTM E 108 or UL 790, Class A; for application and roof slopes indicated; testing by a qualified testing agency. Identify products with appropriate markings of applicable testing agency. I. Fire-Resistance Ratings: Comply with fire-resistance-rated assembly designs indicated. Identify products with appropriate markings of applicable testing agency. 2.2 POLYVINYL CHLORIDE (PVC) ROOFING A. PVC Sheet: ASTM D 4434, Type II, glass-fiber reinforced, felt backed. 1. Manufacturer: Sika Sarnafil or Carlisle THE KENT 07 54 19 - THE KENT Issue Date 05.09.18 PVC ROOFING THE KENT 2. Product: Sikaplan Adhered Energy Smart Roof Membrane System or Carlisle Sure-Flex 3. Thickness: 60 mils. 4. Exposed Face Color: Black or Carlisle Grey. B. Source Limitations: Obtain components for roofing system from roof membrane manufacturer or manufacturers approved by roof membrane manufacturer. 2.3 AUXILIARY ROOFING MATERIALS A. General: Auxiliary materials recommended by roofing system manufacturer for intended use and compatible with other roofing components. 1. Adhesives and Sealants: Comply with VOC limits of authorities having jurisdiction. 2. Adhesives and sealants shall comply with the following limits for VOC content: a. Plastic Foam Adhesives: 50 g/L. b. Gypsum Board and Panel Adhesives: 50 g/L. c. Multi-purpose Construction Adhesives: 70 g/L. d. Fiberglass Adhesives: 80 g/L. e. Contact Adhesives: 80 g/L. f. PVC Welding Compounds: 510 g/L. g. Other Adhesives: 250 g/L. h. Single-Ply Roof Membrane Sealants: 450 g/L. i. Non-membrane Roof Sealants: 300 g/L. j. Sealant Primers for Non-Porous Substrates: 250 g/L. k. Sealant Primers for Porous Substrates: 775 g/L. 3. Adhesives and sealants shall comply with the testing and product requirements of the California Department of Public Health's "Standard Method for the Testing and Evaluation of Volatile Organic Chemical Emissions from Indoor Sources Using Environmental Chambers." B. Sheet Flashing: Manufacturer's standard sheet flashing of same material, type, reinforcement, thickness, and color as PVC sheet. C. Prefabricated Pipe Flashings: As recommended by roof membrane manufacturer. D. Roof Vents: As recommended by roof membrane manufacturer. 1. Size: Not less than 4-inch diameter. E. Sheet Metal Drain Sump Pan: Refer to Specification Section 07 62 00 “Sheet Metal Flashing and Trim.” F. Roof Drain: Refer to Specification Section 22 13 16 “Drainage and Vent Systems.” G. Bonding Adhesive: Manufacturer's standard, water based. H. Water-Based, Fabric-Backed Membrane Adhesive: Roofing system manufacturer's standard water-based, cold-applied adhesive formulated for compatibility and use with fabric-backed membrane roofing. I. Metal Termination Bars: Manufacturer's standard, predrilled stainless steel or aluminum bars, approximately 1 by 1/8-inch-thick; with anchors. THE KENT 07 54 19 - THE KENT Issue Date 05.09.18 PVC ROOFING THE KENT J. Fasteners: Factory-coated steel fasteners and metal or plastic plates complying with corrosion- resistance provisions in FM Approvals 4470, designed for fastening roofing components to substrate, and acceptable to roofing system manufacturer. K. Miscellaneous Accessories: Provide pourable sealers, preformed cone and vent sheet flashings, preformed inside and outside corner sheet flashings, T-joint covers, lap sealants, termination reglets, and other accessories. 2.4 SUBSTRATE BOARDS A. Substrate Board: ASTM C 1177, glass-mat, water-resistant gypsum substrate or ASTM C 1278, fiber-reinforced gypsum board. 1. Manufacturer: Georgia-Pacific Building products. 2. Product: DensDeck Prime. 3. Thickness: Type X, 5/8 inch. B. Fasteners: Factory-coated steel fasteners and metal or plastic plates complying with corrosion- resistance provisions in FM Approvals 4470, designed for fastening substrate board to roof deck. 2.5 VAPOR RETARDER A. Polyethylene Film: ASTM D 4397, 6 mils thick, minimum. 1. Tape: Pressure-sensitive tape of type recommended by vapor retarder manufacturer for sealing joints and penetrations in vapor retarder. 2. Adhesive: Manufacturer's standard lap adhesive, listed by FM Approvals for vapor retarder application. 2.6 ROOF INSULATION A. General: Preformed roof insulation boards manufactured or approved by PVC roof membrane manufacturer, approved for use in FM Approvals' RoofNav listed roof assemblies. B. Polyisocyanurate Board Insulation: ASTM C 1289, Type II, Class 1, Grade 2, felt or glass-fiber mat facer on both major surfaces. 1. Manufacturers: Subject to requirements, provide products by one of the following: a. Atlas Roofing Corp. b. Firestone Building Product Company. c. GAF. d. Johns Manville. e. Rmax Operating, LLC. C. Tapered Insulation: Provide factory-tapered insulation boards. 1. Material: Match roof insulation. 2. Minimum Thickness: 1/4 inch. 3. Slope: a. Roof Field: 1/4 inch per foot unless otherwise indicated on Drawings. b. Saddles and Crickets: 1/2 inch per foot unless otherwise indicated on Drawings. THE KENT 07 54 19 - THE KENT Issue Date 05.09.18 PVC ROOFING THE KENT 2.7 INSULATION ACCESSORIES A. General: Roof insulation accessories recommended by insulation manufacturer for intended use and compatibility with other roofing system components. B. Insulation Adhesive: Insulation manufacturer's recommended adhesive formulated to attach roof insulation to substrate or to another insulation layer as follows: 1. Modified asphaltic, asbestos-free, cold-applied adhesive. 2. Bead-applied, low-rise, one-component or multicomponent urethane adhesive. 3. Full-spread, spray-applied, low-rise, two-component urethane adhesive. 4. Adhesives and sealants shall comply with the following limits for VOC content: a. Plastic Foam Adhesives: 50 g/L. b. Gypsum Board and Panel Adhesives: 50 g/L. c. Multi-purpose Construction Adhesives: 70 g/L. d. Fiberglass Adhesives: 80 g/L. e. Contact Adhesives: 80 g/L. f. PVC Welding Compounds: 510 g/L. g. Other Adhesives: 250 g/L. h. Single-Ply Roof Membrane Sealants: 450 g/L. i. Non-membrane Roof Sealants: 300 g/L. j. Sealant Primers for Nonporous Substrates: 250 g/L. k. Sealant Primers for Porous Substrates: 775 g/L. 5. Adhesives and sealants shall comply with the testing and product requirements of the California Department of Public Health's "Standard Method for the Testing and Evaluation of Volatile Organic Chemical Emissions from Indoor Sources Using Environmental Chambers." C. Cover Board: ASTM C 1177, glass-mat, water-resistant gypsum board. 1. Manufacturer: Georgia-Pacific Building Products. a. Product: DensDeck Prime. 2. Thickness: 5/8 inch. 2.8 WALKWAYS A. Flexible Walkways: Factory-formed, non-porous, heavy-duty, slip-resisting, surface-textured walkway pads, approximately 3/16-inch-thick and acceptable to roofing system manufacturer. PART 3 - EXECUTION 3.1 EXAMINATION A. Examine substrates, areas, and conditions, with Installer present, for compliance with requirements and other conditions affecting performance of the Work. 1. Verify that roof openings and penetrations are in place, curbs are set and braced, and roof-drain bodies are securely clamped in place. 2. Verify that wood blocking, curbs, and nailers are securely anchored to roof deck at penetrations and terminations and that nailers match thicknesses of insulation. THE KENT 07 54 19 - THE KENT Issue Date 05.09.18 PVC ROOFING THE KENT 3. Verify that surface plane flatness and fastening of steel roof deck complies with requirements in Section 05 31 00 "Steel Decking." B. Proceed with installation only after unsatisfactory conditions have been corrected. 3.2 PREPARATION A. Clean substrate of dust, debris, moisture, and other substances detrimental to roofing system installation according to roofing system manufacturer's written instructions. Remove sharp projections. B. Prevent materials from entering and clogging roof drains and conductors and from spilling or migrating onto surfaces of other construction. Remove roof-drain plugs when no work is taking place or when rain is forecast. C. Install sound-absorbing insulation strips according to acoustical roof deck manufacturer's written instructions. 3.3 ROOFING INSTALLATION, GENERAL A. Install roofing system according to roofing system manufacturer's written instructions. B. Complete terminations and base flashings and provide temporary seals to prevent water from entering completed sections of roofing system at end of workday or when rain is forecast. Remove and discard temporary seals before beginning work on adjoining roofing. 3.4 SUBSTRATE BOARD INSTALLATION A. Install substrate board with long joints in continuous straight lines, with end joints staggered not less than 24 inches in adjacent rows. 1. Fasten substrate board to top flanges of steel deck according to recommendations in FM Approvals' RoofNav assembly requirements and FM Global Property Loss Prevention Data Sheet 1-29 for specified Windstorm Resistance Classification. 2. Fasten substrate board to top flanges of steel deck to resist uplift pressure at corners, perimeter, and field of roof according to roofing system manufacturers' written instructions. 3.5 VAPOR RETARDER INSTALLATION A. Vapor-Retarder and Air-Barrier: Roll out membrane over clean dry metal deck and secure in place using roofing system manufacturer’s written recommendation. B. Seal any penetrations of roof’s vapor barrier based on system manufacturer’s written recommendations. THE KENT 07 54 19 - THE KENT Issue Date 05.09.18 PVC ROOFING THE KENT 3.6 INSULATION INSTALLATION A. Coordinate installing roofing system components so insulation is not exposed to precipitation or left exposed at end of workday. B. Comply with roofing system and insulation manufacturer's written instructions for installing roof insulation. C. Installation over wood decking: 1. Install base layer of insulation with joints staggered not less than 24 inches in adjacent rows. a. Locate end joints over crests of decking. b. Where installing composite and non-composite insulation in two or more layers, install non-composite board insulation for bottom layer and intermediate layers, if applicable, and install composite board insulation for top layer. c. Trim insulation neatly to fit around penetrations and projections, and to fit tight to intersecting sloping roof decks. d. Make joints between adjacent insulation boards not more than 1/4 inch in width. e. At internal roof drains, slope insulation to create a square drain sump with each side equal to the diameter of the drain bowl plus 24 inches. 1) Trim insulation so that water flow is unrestricted. f. Fill gaps exceeding 1/4 inch with insulation. g. Cut and fit insulation within 1/4 inch of nailers, projections, and penetrations. Retain first subparagraph below for loosely laid and ballasted roofing systems. h. Mechanically attach base layer of insulation and substrate board using mechanical fasteners specifically designed and sized for fastening specified board-type roof insulation to wood decks. 1) Fasten insulation according to requirements in FM Approvals' RoofNav for specified Windstorm Resistance Classification. 2) Fasten insulation to resist specified uplift pressure at corners, perimeter, and field of roof. 2. Install upper layers of insulation with joints of each layer offset not less than 12 inches from previous layer of insulation. a. Staggered end joints within each layer not less than 24 inches in adjacent rows. b. Install with long joints continuous and with end joints staggered not less than 12 inches in adjacent rows. c. Trim insulation neatly to fit around penetrations and projections, and to fit tight to intersecting sloping roof decks. d. Make joints between adjacent insulation boards not more than 1/4-inch n width. e. At internal roof drains, slope insulation to create a square drain sump with each side equal to the diameter of the drain bowl plus 24 inches. f. Trim insulation so that water flow is unrestricted. g. Fill gaps exceeding 1/4 inch with insulation. h. Cut and fit insulation within 1/4 inch of nailers, projections, and penetrations. i. Adhere each layer of insulation to substrate using adhesive according to FM Approvals' RoofNav assembly requirements and FM Global Property Loss Prevention Data Sheet 1-29 for specified Windstorm Resistance Classification, as follows: 1) Set each layer of insulation in a solid mopping of hot roofing asphalt, applied within plus or minus 25 deg F of equiviscous temperature. 2) Set each layer of insulation in ribbons of bead-applied insulation adhesive, firmly pressing and maintaining insulation in place. THE KENT 07 54 19 - THE KENT Issue Date 05.09.18 PVC ROOFING THE KENT 3) Set each layer of insulation in a uniform coverage of full-spread insulation adhesive, firmly pressing and maintaining insulation in place. 3.7 INSTALLATION OF COVER BOARDS A. Install cover boards over insulation with long joints in continuous straight lines with end joints staggered between rows. Offset joints of insulation below a minimum of 6 inches in each direction. 1. Trim cover board neatly to fit around penetrations and projections, and to fit tight to intersecting sloping roof decks. 2. At internal roof drains, conform to slope of drain sump. a. Trim cover board so that water flow is unrestricted. 3. Cut and fit cover board tight to nailers, projections, and penetrations. 4. Adhere cover board to substrate using adhesive according to FM Approvals' RoofNav assembly requirements and FM Global Property Loss Prevention Data Sheet 1-29 for specified Windstorm Resistance Classification, as follows: B. Install slip sheet over cover board and immediately beneath roof membrane. 3.8 ADHERED ROOFING INSTALLATION A. Adhere roof membrane over area to receive roofing according to roofing system manufacturer's written instructions. B. Unroll roof membrane and allow to relax before installing. C. Start installation of roofing in presence of roofing system manufacturer's technical personnel. D. Accurately align roof membrane and maintain uniform side and end laps of minimum dimensions required by manufacturer. Stagger end laps. E. Fabric-Backed Roof Membrane Adhesive: Apply to substrate at rate required by manufacturer and install fabric-backed roof membrane. F. In addition to adhering, mechanically fasten roof membrane securely at terminations, penetrations, and perimeter of roofing. G. Apply roof membrane with side laps shingled with slope of roof deck where possible. H. Seams: Clean seam areas, overlap roofing, and hot-air weld side and end laps of roof membrane and sheet flashings to ensure a watertight seam installation. 1. Test lap edges with probe to verify seam weld continuity. Apply lap sealant to seal cut edges of roof membrane and sheet flashings. 2. Verify field strength of seams a minimum of twice daily, and repair seam sample areas. 3. Repair tears, voids, and lapped seams in roof membrane that do not comply with requirements. I. Spread sealant bed over deck-drain flange at roof drains, and securely seal roof membrane in place with clamping ring. THE KENT 07 54 19 - THE KENT Issue Date 05.09.18 PVC ROOFING THE KENT 3.9 BASE FLASHING INSTALLATION A. Install sheet flashings and preformed flashing accessories and adhere to substrates according to roofing system manufacturer's written instructions. B. Apply bonding adhesive to substrate and underside of sheet flashing at required rate and allow to partially dry. Do not apply to seam area of flashing. C. Flash penetrations and field-formed inside and outside corners with cured or uncured sheet flashing. D. Clean seam areas, overlap, and firmly roll sheet flashings into the adhesive. Hot-air weld side and end laps to ensure a watertight seam installation. E. Terminate and seal top of sheet flashings and mechanically anchor to substrate through termination bars. 3.10 WALKWAY INSTALLATION A. Flexible Walkways: Install walkway products according to manufacturer's written instructions. 1. Install flexible walkways at the following locations: a. Perimeter of each rooftop unit. b. Between each rooftop unit location, creating a continuous path connecting rooftop unit locations. c. Between each roof hatch and each rooftop unit location or path connecting rooftop unit locations. d. Top and bottom of each roof access ladder. e. Between each roof access ladder and each rooftop unit location or path connecting rooftop unit locations. f. Locations indicated on Drawings. g. As required by roof membrane manufacturer's warranty requirements. 2. Provide 6-inch clearance between adjoining pads. 3. Heat weld to substrate or adhere walkway products to substrate with compatible adhesive according to roofing system manufacturer's written instructions. 3.11 FIELD QUALITY CONTROL A. Testing Agency: Owner will engage a qualified testing agency to inspect substrate conditions, surface preparation, roof membrane application, sheet flashings, protection, and drainage components, and to furnish reports to Architect. B. Owner will engage a qualified testing agency to perform the following tests: 1. Flood Testing: Flood test each roofing area for leaks, according to recommendations in ASTM D 5957, after completing roofing and flashing but before overlying construction is placed. Install temporary containment assemblies, plug or dam drains, and flood with potable water. a. Perform tests before overlying construction is placed. THE KENT 07 54 19 - THE KENT Issue Date 05.09.18 PVC ROOFING THE KENT b. Flood to an average depth of 2-1/2 inches with a minimum depth of 1 inch and not exceeding a depth of 4 inches. Maintain 2 inches of clearance from top of base flashing. c. Flood each area for 24 hours. d. After flood testing, repair leaks, repeat flood tests, and make further repairs until roofing and flashing installations are watertight. 1) Cost of retesting is Contractor's responsibility. e. Testing agency shall prepare survey report indicating locations of initial leaks, if any, and final survey report. 2. Low-Voltage Electrical Conductance Testing: Testing agency shall survey entire roof area and flashings to locate discontinuity in the roof membrane using an exposed metal electrical loop to create an electrical field tested with handheld probes or a scanning platform with integral perimeter electrical loops creating a complete electrical field. a. Perform tests before overlying construction is placed. b. After testing, repair areas of discontinuities, repeat tests, and make further repairs until roofing and flashing installations are contiguous. 1) Cost of retesting is Contractor's responsibility. c. Testing agency shall prepare survey report indicating locations of initial discontinuities, if any. 3. Testing agency shall prepare survey report indicating locations of initial discontinuities, if any. C. Final Roof Inspection: Arrange for roofing system manufacturer's technical personnel to inspect roofing installation on completion, in presence of Architect, and to prepare inspection report. D. Repair or remove and replace components of roofing system where inspections indicate that they do not comply with specified requirements. E. Additional testing and inspecting, at Contractor's expense, will be performed to determine if replaced or additional work complies with specified requirements. 3.12 PROTECTING AND CLEANING A. Protect roofing system from damage and wear during remainder of construction period. When remaining construction does not affect or endanger roofing, inspect roofing system for deterioration and damage, describing its nature and extent in a written report, with copies to Architect and Owner. B. Correct deficiencies in or remove roofing system that does not comply with requirements, repair substrates, and repair or reinstall roofing system to a condition free of damage and deterioration at time of Substantial Completion and according to warranty requirements. C. Clean overspray and spillage from adjacent construction using cleaning agents and procedures recommended by manufacturer of affected construction. END OF SECTION 07 54 19