070150.74 Rehabilitation of EPDM Roofing.pdf

James H. Quillen VA Medical Center, Project 621-20-101

AE Correct FCA Deficiencies with Historical Chapel Bldg 13

Amendment 0005

REHABILITATION OF EPDM ROOFING

07 01 50.74 - 1

SECTION 07 01 50.74

PART 1 - GENERAL

1.1 RELATED DOCUMENTS

A. Drawings and general provisions of the Contract, including General and Supplementary Conditions and Division 1 Specification Sections apply to this Section.

1.2 SUMMARY

A. This Section includes the following:

1. Roof rehabilitation preparation including roof repair and cleaning preparation.

2. Rehabilitation of base flashings.

3. Application of fluid-applied roof membrane and flashings over existing single ply membrane areas.

4. Warranty.

B. Related Documents:

1. The Contract Documents apply to the Work of this Section.

Additional requirements and information necessary to complete the

Work of this Section may be found in other documents.

C. Related Sections:

1. Division 7 Section: Flashing and Sheet Metal.

2. Division 7 Section: Preparation for Re-Roofing.

1.3 DEFINITIONS

A. Roofing Terminology: Refer to ASTM D 1079 and glossary of NRCA's

"The NRCA Roofing and Waterproofing Manual" for definition of terms related to roofing work in this Section.

B. Existing Roofing System: Single ply roofing, components and accessories between deck and roofing membrane.

C. Roofing Rehabilitation Preparation: Existing roofing that is to remain and be prepared to accept restorative fluid applied membrane application.

D. Patching: Removal of a portion of existing membrane roofing system from deck and replacement with similar materials.

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E. Remove: Detach items from existing construction and legally dispose of them off-site unless indicated to be removed and reinstalled.

F. Existing to Remain: Existing items of construction that are not indicated to be removed.

1.4 PERFORMANCE REQUIREMENTS

A. General: Provide recoated roofing membrane and base flashings that remain watertight; do not permit the passage of water; and resist specified uplift pressures, thermally induced movement, and exposure to weather without failure.

B. Material Compatibility: Provide roofing materials that are compatible with one another under conditions of service and application required, as demonstrated by roofing manufacturer based on testing and field experience.

C. Exterior Fire-Test Exposure: ASTM E 108, Class A; for application and roof slopes indicated, as determined by testing identical membrane roofing materials by a qualified testing agency.

Materials shall be identified with appropriate markings of applicable testing agency.

1.5 SUBMITTALS

A. Product Data:

1. For each type of product specified.

B. Assurance/Control Submittals:

1. Certificates: Manufacturer certificate that components and products as a system meet or exceed specified standards and complies with referenced standards.

2. Manufacturer’s certification letter acknowledging receipt of specifications, intent to issue warranty, and intent to perform specified field inspection and reports.

a. Manufacturer's Construction Observation: Submit letter from the manufacturer indicating who the technical inspector will be, experience qualifications, assurance of non-sales related functions or Registered Roof Observer certification along with copies of prior reports.

1) Inspector Requirements & Qualifications: Engage an experienced technical inspector to perform daily job

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07 01 50.74 - 3 monitoring for this project. Inspector shall be specialized in inspecting roofing similar to that required for this Project; must have a minimum of five years experience providing roof construction monitoring and shall have no manufacturer sales responsibilities; must be full time employee of the roofing system manufacturer to inspect the project daily and provide daily written reports to the Owner Representatives. The approved inspector must be certified as a Registered Roof Observer by the Roof Consultants Institute.

a) Preparatory inspection.

b) Initial inspection.

c) Daily inspections.

d) Final inspection

C. Installer Certificates: Signed by roofing system manufacturer certifying that Installer is approved, authorized, or licensed by manufacturer to install proposed roofing system with minimum of 3 years documented experience with proposed roof system manufacturer.

D. Manufacturer Certificates: Signed by roofing manufacturer certifying that roofing system complies with all requirements of this Section and the overall project requirements.

1. Submit evidence of meeting performance requirements.

E. Qualification Data: For Installer and manufacturer.

F. Product Test Reports: Based on evaluation of comprehensive tests performed by manufacturer and witnessed by a qualified testing agency, for components of roofing system.

G. Research/Evaluation Reports: For components of roofing system.

H. Maintenance Data: For roofing system to include in maintenance manuals.

I. Warranties: Special warranties specified in this Section.

J. Inspection Report: Copy of roofing system manufacturer's inspection report of completed roofing installation.

1.6 QUALITY ASSURANCE

A. Installer Qualifications: A qualified firm that is approved, authorized, or licensed by roofing system manufacturer to install

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07 01 50.74 - 4 manufacturer's product and that is eligible to receive manufacturer's warranty.

B. Manufacturer's Field Reports: Submit the following reports directly to the project construction manager, with copy to others as requested.

1. Inspector Requirements & Qualifications: Engage an experienced technical inspector, to perform daily job monitoring for this project. Inspector shall be specialized in inspecting roofing similar to that required for this Project; must have a minimum of five years experience providing roof construction monitoring and shall have no manufacturer sales responsibilities; must be full time employee of the roofing system manufacturer to daily inspect the manufacturer's project and provide daily written reports to the

Owner Representatives. The approved inspector must be certified as a Registered Roof Observer by the Roof Consultants Institute.

a. Preparatory inspection.

b. Initial inspection.

c. Daily inspections.

d. Final inspection.

C. Source Limitations: Obtain all roofing rehabilitation services, patching materials, sheet flashings and restoration system from a single manufacturer issuing the rehabilitation roof system warranty. All components shall be supplied and warranted by the proposed roof system manufacturer.

D. Pre-installation Roofing Rehabilitation Conference: Conduct conference at Project site to comply with requirements in Division

01. Review methods and procedures related to roofing system.

1. Job-site photos.

2. Meet with Owner; roofing re-coating materials manufacturer's representative; roofing re-coating Installer including project manager and foreman; and installers whose work interfaces with or affects re-coating including installers of roof accessories and roof-mounted equipment requiring removal and replacement as part of the Work.

3. Review methods and procedures related to re-coating preparation, including membrane roofing system manufacturer's written instructions.

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4. Review temporary protection requirements for existing roofing system that is to remain, during and after installation.

5. Review roof drainage during each stage and review roof drain plugging and plug removal procedures.

6. Review and finalize construction schedule, and verify availability of materials, Installer's personnel, equipment, and facilities needed to make progress and avoid delays.

7. Review base flashings, special roofing details, drainage, penetrations, equipment curbs, and condition of other construction that will affect re-coating.

8. Review HVAC shutdown and sealing of air intakes.

9. Review shutdown of fire-suppression, -protection, and -alarm and -detection systems.

10. Review procedures for asbestos removal or unexpected discovery of asbestos-containing materials.

11. Review governing regulations and requirements for insurance and certificates if applicable.

12. Review existing conditions that may require notification of Owner before proceeding.

E. Project Closeout Reports: Provide a report upon delivery of the project warranty. This report to include:

1. Project Specifications.

2. Project Summary.

3. Progress reports as a result of roof inspections.

4. Job-site progress photos.

5. Compiled project video

6. Executed Contractor Guarantee

7. Manufacturer warranty document

8. Owners’ manual describing maintenance and emergency repair.

9.

1.7 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, and directions for storage.

B. Store liquid materials in their original undamaged containers in a clean, dry, protected location and within the temperature range

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07 01 50.74 - 6 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. Handle and store roofing materials and place equipment in a manner to avoid permanent deflection of deck.

1.8 PROJECT CONDITIONS

A. Owner will occupy portions of building immediately below roof work area. Conduct roofing work so that Owner's operations will not be disrupted. Provide Owner with not less than 72 hours' notice of activities that may affect Owner's operations.

B. Protect building to be rehabilitated, adjacent buildings, walkways, site improvements, exterior plantings, and landscaping from damage or soiling from rehabilitation operations.

C. Maintain access to existing walkways, corridors, and other adjacent occupied or used facilities.

D. Weather Limitations: Proceed with rehabilitation work only when existing and forecasted weather conditions permit Work to proceed without water entering into existing roofing system or building.

1. Store all materials prior to application at temperatures between 60 and 90 deg. F.

2. Apply fluid applied system components within range of ambient and substrate temperatures recommended by manufacturer. Do not apply materials when air temperature is below 50 or above 110 deg. F.

3. Do not apply roofing in snow, rain, fog, or mist.

1.9 WARRANTY

A. Construction Warranty: FAR clause 52.246 21, "Warranty of

Construction."

B. Manufacturer's Warranty: Warrant roofing system against material and manufacturing defects and agree to repair any leak caused by a defect in the roofing system materials or workmanship of the installer and provide performance warranty service visits at years

2, 5, 10, & 15 to inspect roof system, remove accumulated roof debris and provide a list of Owner maintenance requirements to maintain warranty continuity. A single roof system manufacturer

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07 01 50.74 - 7 shall provide all roof system warranties for the entire project.

Warranty shall offer renewable option for an additional length as desired by Owner.

1. Warranty Period: 20 years from date of Substantial Completion.

PART 2 - PRODUCTS

2.1 MATERIALS

A. General: Rehabilitation materials provided by roofing system manufacturer for intended use and compatible with components of existing membrane roofing system.

B. Patching Materials: Where required to patch existing roofing, use materials matching existing membrane roofing system type as provided by the warranting roof rehabilitation system manufacturer.

2.2 VAPOR RETARDER MEMBRANE SYSTEM

A. Ply Sheet: ASTM D 6163, Grade S, Type III, glass-fiber-reinforced, SBS-modified asphalt sheet smooth surfaced, suitable for application specified.

B. Cold-Applied Adhesive: Roofing system manufacturer's standard one- or two-part, 70% Bio Based, 100% solids, asbestos-free, ultra low VOC, cold-applied adhesive specially formulated for compatibility and use with roofing membrane sheets.

2.3 RECOVERY BOARD

A. General: Provide recovery boards that comply with requirements and referenced standards, selected from manufacturer's standard sizes and of thicknesses indicated.

B. Recovery Board: ASTM C 1177, impact resistant, nonstructural, fiber reinforced gypsum panels, 1/4 inch (6 mm), thick. Provide with recycled content to the greatest extent possible.

2.4 EPDM ROOFING MEMBRANE

A. EPDM Sheet: ASTM D4637/D4637M, Type III - fabric backed.

B. Thickness: 2.54 mm (100 mils).

C. Color: Black.

D. Additional Properties:

PROPERTY TEST METHOD REQUIREMENT

Shore A Hardness ASTM D2240 55 to 75 Durometer

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Water Vapor Permeance ASTM E96/E96M Minimum 8 ng/Pa/s/sq. m

(0.14 perms) Water

Method

Fungi Resistance ASTM G21 After 21 days, no sustained growth or discoloration.

1. Use fire retardant membrane when not protected by ballast or pavers.

Verify for UL or approval.

2.5 FLUID-APPLIED ROOFING MEMBRANE REHABILITATION SYSTEM

A. Polyurethane Elastomeric Leveling Coat: One or two part, asbestos free, ultra low volatile organic compound, polyurethane leveling coat formulated to be applied over EPDM roof systems:

1. Solids, by volume, ASTM D 2697: 100 percent.

2. Bio Based Content, ASTM D6866, 70% minimum.

B. Urethane Base Coat:

1. ASTM D7311, Single component, moisture triggered, aliphatic polyurethane roofing membrane, suitable for application method specified.

2. ASTM C957, Single or multi component, polyurethane roofing membrane, suitable for application method specified.

a. Bio Based Content, ASTM D6866, 70% minimum.

C. Urethane Top Coat:

1. ASTM D7311, Single component, moisture triggered, aliphatic polyurethane roofing membrane suitable for application method specified.

2. ASTM C957, Single or multi component, polyurethane roofing membrane, suitable for application method specified.

a. Bio Based Content, ASTM D6866, 70% minimum.

D. Polyester Reinforcement: 100% stitch bonded polyester fabric for fluid-applied membrane and flashing by roofing rehabilitation system manufacturer.

E. Miscellaneous Accessories: Provide miscellaneous accessories recommended by roofing rehabilitation system manufacturer.

2.6 AUXILIARY ROOFING COATING MATERIALS

A. Sheet roofing manufacturer's specified products.

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B. Flashing Sheet: Manufacturer's standard; same material, and color as roofing membrane.

1. Self-curing EPDM flashing adaptable to irregular shapes and surfaces.

2. Minimum Thickness: 1.5 mm (0.060 inch).

C. Factory Formed Flashings: Inside and outside corners, pipe boots, and other special flashing shapes to minimize field fabrication.

D. Splice Adhesive or Tape: Manufacturer's standard for roofing membrane and flashing sheet.

E. Splice Lap Sealant: Liquid EPDM rubber for exposed lap edge.

F. Bonding Adhesive: Manufacturer's standard, water-based, to suit substrates.

G. Fasteners: Manufacturer's standard coated steel with metal or plastic plates, to suit application.

H. Fastener Sealer: One part elastomeric adhesive sealant.

I. Temporary Closure Sealers (Night Sealant): Polyurethane two part sealer.

J. Primers, Splice Tapes, Cleaners, and Butyl Rubber Seals: As specified by roof membrane manufacturer.

K. Asphalt Roof Cement: ASTM D4586/D4586M.

PART 3 - EXECUTION

3.1 EXAMINATION

A. Examine existing roofing substrates, with Installer present, for compliance with requirements and for other conditions affecting application and performance of fluid applied roof membrane system.

1. Prepare a written report listing any conditions detrimental to finished system performance.

2. Verify compatibility of system with substrates.

3. Verify that substrates are visibly dry and free of moisture.

4. Verify that roofing membrane surfaces have adequately aged to enable proper bond with rehabilitation system base coat.

5. Verify that existing roofing membrane is free of blisters, splits, open laps, indications of shrinkage, and puncture damage or other indications that will impair finished system performance

6. Application of fluid-applied membrane restoration system indicates acceptance of surfaces and conditions.

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3.2 PREPARATION

A. Protect existing roofing system and adjacent portions of building and building equipment.

1. Mask surfaces to be protected. Seal joints subject to infiltration by coating materials.

2. Limit traffic and material storage to areas of existing roofing membrane that have been protected.

3. Maintain temporary protection and leave in place until replacement roofing has been completed.

B. Shut down air intake equipment in the vicinity of the Work in coordination with the Owner. Cover air intake louvers before proceeding with work that could affect indoor air quality or activate smoke detectors in the ductwork.

1. Verify that rooftop utilities and service piping affected by the

Work have been shut off before commencing Work.

C. Maintain roof drains in functioning condition to ensure roof drainage at end of each workday. Contractor is responsible for maintaining roof drains in a watertight condition during all roof work. Prevent debris from entering or blocking roof drains and conductors. Use roof-drain plugs specifically designed for this purpose. Remove roof-drain plugs at end of each workday, when no work is taking place, or when rain is forecast.

1. Do not permit water to enter into or under existing membrane roofing system components that are to remain.

3.3 DESIGNATED ROOF REPLACEMENT AREAS

A. Ensure deck surface is clean and dry. Prime surface as required by manufacturer

B. Install one ply vapor retarder to deck in solid application of cold applied adhesive. Completely seal temporary roof/vapor retarder at terminations, obstructions, and penetrations to prevent air movement and water entry into roofing system.

C. Coordinate installing roofing system components so insulation is not exposed to precipitation or left exposed at the end of the workday.

D. Comply with roofing system manufacturer's written instructions for installing roof insulation.

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E. Install each layer of cover board to substrate. Stagger joints all joints a minimum of 6 inches (150 mm) in each direction.

1. Apply insulation adhesive to substrate at rate approved and tested by manufacturer to comply with windstorm requirements and immediately bond insulation board and cover board to substrate.

F. Install roofing membrane system according to roofing system manufacturer's written instructions and applicable recommendations of ARMA/NRCA's "Quality Control Guidelines for the Application of Polymer Modified Bitumen Roofing."

G. Start installation of roofing membrane in presence of roofing system manufacturer's technical personnel.

H. Provide tie-offs at end of each day's work to cover exposed roofing membrane sheets and insulation with a course of coated felt set in roofing cement or hot roofing asphalt with joints and edges sealed.

I. Complete terminations and base flashings and provide temporary seals to prevent water from entering completed sections of roofing system.

J. Substrate-Joint Penetrations: Prevent roofing adhesives from penetrating substrate joints, entering building, or damaging roofing system components or adjacent building construction.

K. Install one roofing membrane according to roofing manufacturer's written instructions, starting at low point of roofing system.

Install as follows:

1. Adhere to substrate in a solid application of cold process roofing membrane adhesive.

2. If recommended by manufacturer, unroll roofing membrane, and allow to relax for minimum time period required by manufacturer.

3. Ensure membrane embedment into cold adhesive by rolling membrane with a 75# roller.

L. Laps: Accurately align roofing membrane, without stretching, and maintain uniform side and end laps. Stagger end laps. Completely bond and seal laps, leaving no voids.

1. Repair tears and voids in laps and lapped seams not completely sealed.

2. Heat weld all end and side laps to ensure daily watertight bond.

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M. Install roofing membrane sheets so side and end laps shed water.

3.4 ROOFING REHABILITATION PREPARATION

A. Membrane Surface Preparation:

1. Remove blisters, ridges, buckles, and other substrate irregularities from existing roofing membrane that would inhibit application of uniform, waterproof coating.

2. Repair membrane at locations where irregularities have been removed.

3. Clean substrate of contaminants such as dirt, debris, oil, and grease that can affect adhesion of coating with a self-contained pressure washing and recovery system to prevent cleaning water and any detergents from entering the roof and storm drain system. Allow to dry thoroughly.

4. Verify that existing substrate is dry before proceeding with application of fluid applied membrane system. Spot check substrates with an electrical capacitance moisture-detection meter.

5. Verify adhesion of new fluid applied system products to determine if EPDM surface primer is needed to obtain specified roof rehabilitation system warranty.

3.5 FLASHING REPAIR

A. Do not damage metal counterflashings that are to remain. Replace metal counterflashings damaged during project or indicated on drawings with counterflashings of same metal, weight or thickness, and finish.

B. Repair flashings, gravel stops, copings, and other roof-related sheet metal and trim elements. Reseal joints, storm collar flashings, replace loose or missing fasteners, and replace components where required to leave in existing flashings in a watertight condition.

C. Prime metal surfaces with manufacturers recommended primer.

3.6 SINGLE PLY MEMBRANE FLUID APPLIED MEMBRANE APPLICATION

A. Prime surface according to manufacturer requirements and allow to dry.

B. Apply base coat material and back roll to achieve wet mil thickness of 48 mils unless otherwise recommended by manufacturer.

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C. Install reinforcing membrane to entire roof field area per manufacturer instructions and work reinforcing membrane into wet coating to ensure complete saturation. Top dress reinforcing membrane as required. Leave finished base coat with fabric free of pin holes, voids, or openings

D. Prime base coat prior to application of top coat if top coat is not applied within 72 hours of the base coat application, using manufacturer's recommended primer.

E. Apply top coat over field base coat and spread coating evenly.

F. Back roll to achieve wet mil thickness of 48 mils unless otherwise recommended by manufacturer.

G. Avoid foot traffic on new fluid-applied membrane for a minimum of

24 hours.

3.7 FIELD QUALITY CONTROL

A. Field Inspections:

1. Roof rehabilitation system manufacturer representative to inspect installation daily to verify compliance with rehabilitation warranty requirements.

2. Submit reports of field inspections, and supplemental instructions issued during inspections.

3. Certify completed installation complies with manufacturer's instructions and warranty requirements.

3.8 PROTECTING AND CLEANING

A. Protect roofing system from damage and wear during remainder of construction period.

B. Correct deficiencies in or remove coating that does not comply with requirements, repair substrates, and reapply coating.

C. Clean overspray and spillage from adjacent construction using cleaning agents and procedures recommended by manufacturer of affected construction.

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