07 54 23 - Thermoplastic Polyolefin Roofing.pdf

Aquatic Therapy Center and Therapy Center DVA Project Nos.

Building 530 640-370 / 640-CSI-100 VAPAHCS Palo Alto, CA

07 54 23 - 1

SECTION 07 54 23

THERMOPLASTIC POLYOLEFIN (TPO) ROOFING

PART 1 GENERAL

1.1 DESCRIPTION

A. This section includes fully adhered TPO membrane roofing system including interlocking walkway pavers and lightweight concrete pavers.

1.2 RELATED WORK

A. Pre-primed deck board, self adhering vapor barrier, and roof insulation under thermoplastic polyolefin roofing: Section 07 22 00, ROOF AND

DECK INSULATION.

1.3 DEFINITIONS

A. TPO: Thermoplastic polyolefin.

B. Roofing Terminology: See ASTM D1079 and glossary in NRCA's "The NRCA Roofing and Waterproofing Manual" for definitions of terms related to roofing work in this Section.

1.4 PERFORMANCE REQUIREMENTS

A. General Performance: Installed membrane 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. Membrane roofing and base flashings shall remain watertight.

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

C. Energy Performance: Provide roofing system that is listed on the DOE's ENERGY STAR "Roof Products Qualified Product List" for low-slope roof products.

D. Energy Performance: Provide roofing system with initial solar reflectance not less than 0.70 and emissivity not less than 0.75 when tested according to CRRC-1.

1.5 SUBMITTALS

A. Submit in accordance with Section 01 33 23, SHOP DRAWINGS, PRODUCT

DATA, AND SAMPLES.

B. Product Data: For each type of product indicated.

C. Qualification Data: For qualified Installer and manufacturer.

VAPAHCS Palo Alto, CA

07 54 23 - 2

D. Manufacturer Certificates: Signed by roofing manufacturer certifying that roofing system complies with requirements specified in "Performance Requirements" Article.

1. Submit evidence of compliance with performance requirements.

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

F. Field quality-control reports.

G. Warranties: Sample of special warranties.

1.6 QUALITY ASSURANCE

A. Manufacturer Qualifications: A qualified manufacturer that is UL listed for membrane roofing system identical to that used for this Project.

B. Installer Qualifications: A qualified firm that is approved, authorized, or licensed by membrane roofing system manufacturer to install manufacturer's product and that is eligible to receive manufacturer's special warranty.

C. Source Limitations: Obtain components including fasteners for membrane roofing system from same manufacturer as membrane roofing.

D. Exterior Fire-Test Exposure: ASTM E108, 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.

E. Fire-Resistance Ratings: Where indicated, provide fire-resistance-rated roof assemblies identical to those of assemblies tested for fire resistance per ASTM E119 by a qualified testing agency. Identify products with appropriate markings of applicable testing agency.

F. Preliminary Roofing Conference: Before starting roof deck construction, conduct conference at Project site.

1. Meet with Resident Engineer, testing and inspecting agency representative, roofing Installer, roofing system manufacturer's representative, deck 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.

VAPAHCS Palo Alto, CA

07 54 23 - 3

6. Review base flashings, special roofing details, roof drainage, roof penetrations, equipment curbs, and condition of other construction that will affect 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.

G. Preinstallation Roofing Conference: Conduct conference at Project site.

1. Meet with Resident Engineer, testing and inspecting agency representative, roofing Installer, roofing system manufacturer's representative, deck 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 will affect 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.

1.7 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, 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.

VAPAHCS Palo Alto, CA

07 54 23 - 4

D. Handle and store roofing materials and place equipment in a manner to avoid permanent deflection of deck.

1.8 PROJECT 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.

1.9 WARRANTY

A. Roofing work subject to the terms of the Article “Warranty of Construction”, FAR clause 52.246-21, except extend the warranty period to 15 years.

1.10 APPLICABLE PUBLICATIONS

A. Applicable publications listed below form a part of this Specification to extent referenced. Publications are referenced in the text by the number designation only.

B. ASTM International (ASTM):

C90-08..................Loadbearing Concrete Masonry Units

C1549-04................Determination of Solar Reflectance Near Ambient Temperature Using a Portable Solar Reflectomter

D1079-08a...............Terminology Relating to Roofing and Waterproof-ing

D6878-08................Thermoplastic Polyolefin Based Sheet Roofing

E108-07a................Fire Tests pf Roof Coverings

E119-08a................Fire Test of Building Construction and Materi-als

C. National Roofing Contractors Association (NRCA):

"The NRCA Roofing and Waterproofing Manual"

PART 2 PRODUCTS

2.1 TPO MEMBRANE ROOFING

A. Fabric-Reinforced Thermoplastic Polyolefin Sheet: ASTM D6878, internally fabric or scrim reinforced, uniform, flexible TPO sheet.

1. Thickness: 0.080 inch plus/minus 10 percent, with coating thickness over reinforcement of 0.018 inch plus/minus 10 percent.

2. Sheet Width 96 inches

3. Solar Reflectance: 0.79, minimum, when tested in accordance with

ASTM C1549.

VAPAHCS Palo Alto, CA

07 54 23 - 5

4. Exposed Face Color: White.

2.2 AUXILIARY MEMBRANE ROOFING MATERIALS

A. General: Auxiliary membrane roofing materials recommended by roofing system manufacturer for intended use, and compatible with membrane roofing.

1. Liquid-type auxiliary materials shall comply with VOC limits of authorities having jurisdiction.

2. Adhesives and sealants that are not on the exterior side of weather barrier shall comply with the following limits for VOC content when calculated according to 40 CFR 59, Subpart D (EPA Method 24):

a. Plastic Foam Adhesives: 50 g/L.

b. Gypsum Board and Panel Adhesives: 50 g/L.

c. Multipurpose Construction Adhesives: 70 g/L.

d. Fiberglass Adhesives: 80 g/L.

e. Contact Adhesive: 80 g/L.

f. Other Adhesives: 250 g/L.

g. Single-Ply Roof Membrane Sealants: 450 g/L.

h. Nonmembrane Roof Sealants: 300 g/L.

i. Sealant Primers for Nonporous Substrates: 250 g/L.

j. Sealant Primers for Porous Substrates: 775 g/L.

B. Sheet Flashing: Manufacturer's standard unreinforced thermoplastic polyolefin sheet flashing, 1.4 mm (55 mils) thick, minimum, of same color as sheet membrane.

C. TPO Coated Sheet Metal Flashing: Lamination of nonreinforced TPO membrane to 24 gauge galvanized sheet metal, color to match roofing.

D. Bonding Adhesive: Manufacturer's standard, water based.

E. Protection Board: Manufacturer’s standard protection board to be installed over the roof insulation and under roofing, 6.35 mm (1/4 inch) thick.

F. Metal Termination Bars: Manufacturer's standard, predrilled stainless-steel or aluminum bars, approximately 25 by 3 mm (1 by 1/8 inch) thick;

with anchors.

G. Metal Battens: Manufacturer's standard, aluminum-zinc-alloy-coated or zinc-coated steel sheet, approximately 25 mm wide by 1.3 mm thick (1 inch wide by 0.05 inch thick), prepunched.

H. Fasteners: Factory-coated steel fasteners and metal or plastic plates complying with corrosion-resistance provisions in FM Approvals 4470, designed for fastening membrane to substrate, and acceptable to membrane roofing system manufacturer.

I. 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.

VAPAHCS Palo Alto, CA

07 54 23 - 6

J. Interlocking Walkway Pavers:

1. Type: Interlocking rubber pavers weighing approximately 30 kg per square meter (6.0 pounds per square foot). Each rubber paver has a premolded “U” channel on two sides for interlocking. Pavers provide multi-directional drainage.

2. Size: 600 mm by 600 mm by 25 mm (24 inches by 24 inches by 2 inches).

3. Color: As selected by Resident Engineer from manufacturer’s standard color range.

K. Lightweight Concrete Pavers:

1. Weighing not less than 73 kg/m2 (15 pounds per square foot).

2. Non-Interlocking Concrete Masonry Unit Pavers: ASTM C90, Grade N 1.

a. Manufactured using normal weight aggregate.

b. Units of size, shape, and thickness as shown.

c. Ribbed on bottom surface or provided with legs approximately 6 mm

(1/4 inch) high. Legs to distribute weight of paver so bearing does not exceed 69 kPa (10 psi) on the roofing membrane.

PART 3 EXECUTION

3.1 EXAMINATION

A. Examine substrates, areas, and conditions, with Installer present, for compliance with the following requirements and other conditions affecting performance of roofing system:

1. Verify that roof openings and penetrations are in place and curbs are set and braced and that 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.

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 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. Complete terminations and base flashings and provide temporary seals to prevent water from entering completed sections of roofing system at the end of the workday or when rain is forecast. Remove and discard temporary seals before beginning work on adjoining roofing.

VAPAHCS Palo Alto, CA

07 54 23 - 7

3.3 FULLY ADHERE MEMBRANE ROOFING INSTALLATION

A. Fully adhere membrane roofing over area to receive roofing and install according to roofing system manufacturer's written instructions.

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

C. Do not allow the membrane to come in contact with surfaces contaminated with asphalt, coal tar, oil, grease, or other substances which are not compatible with roofing membrane.

D. If possible, install the membrane so the sheets run perpendicular to the long dimension of the insulation boards.

E. If possible, start at the low point of the roof and work towards the high point. Lap the sheets so the flow of water is not against the edges of the sheet. Coordinate with roof insulation installation.

F. Position the membrane so it is free of buckles and wrinkles.

G. Roll sheet out on deck; inspect for defects as sheet is being rolled out and remove defective areas:

1. Allow 30 minutes for relaxing before proceeding.

2. Lap edges and ends of sheets 75 mm (3 inches) or more as recommended by the manufacturer. Clean lap surfaces as specified by manufacturer.

3. Adhesively splice laps. Apply pressure as required. Seam strength of laps as required by ASTM D4637.

4. Check seams to ensure continuous adhesion and correct defects.

5. Finish edges of laps with a continuous beveled bead of lap sealant to sheet edges to provide smooth transition as specified by manufacturer.

6. Finish seams as the membrane is being installed (same day).

7. Anchor perimeter to deck or wall as specified.

H. Membrane Perimeter Anchorage:

1. Install batten strip or steel stress plate with fasteners at the perimeter of each roof level, curb flashing, expansion joints and similar penetrations as indicated in accordance with membrane manufacturer's instructions on top of roof membrane to wall or deck.

2. Mechanically fastened as follows:

a. Top of mechanical fastener set flush with top surface of the nailing strip or stress plate.

b. Space mechanical fasteners a maximum 300 mm (12 inches) on center.

c. Start 25 mm (1 inch) from the end of the nailing strip when used.

d. When strip is cut round edge and corners before installing.

e. Set fasteners in lap sealant and cover fastener head with fastener sealer including batten strip or stress plate.

f. Stop fastening strip where the use of the nailing strip interferes with the flow of the surface water, separate by a 150 mm (6 inch) space, then start again.

VAPAHCS Palo Alto, CA

07 54 23 - 8

g. After mechanically fastening cover and seal with a 225 mm (9 inch) wide strip of flashing sheet. Use splice adhesive on all laps and finish edge with sealant as specified.

I. Adhered System:

1. Apply bonding adhesive in quantities required by roof membrane manufacturer.

2. Fold sheet back on itself, clean and coat the bottom side of the membrane and the top of the deck with adhesive. Do not coat the lap joint area.

3. After adhesive has set according to adhesive manufacturer's application instruction, roll the membrane into the adhesive in manner that minimizes voids and wrinkles.

4. Roll coated membrane into coated substrate while avoiding wrinkles

5. Brush down bonded section of membrane sheet immediately after rolling membrane into adhesive.

6. Fold back unbonded half of sheet and repeat bonding procedures.

7. Repeat for other half of sheet.

8. Cut voids and wrinkles to lay flat and clean for repair patch over cut area.

J. Seams:

1. Clean seam areas, overlap membrane roofing, and hot-air weld side and end laps of membrane roofing and sheet flashings according to manufacturer's written instructions to ensure a watertight seam installation.

2. Weld adjacent sheets in accordance with manufacturer’s written instructions. Hot air weld all side and end lap joints. Weld joints to be minimum 1-1/2 inch wide.

3. Provide welding equipment approved by membrane manufacturer. All mechanics using equipment must successfully complete a course of instruction provided by membrane manufacturer’s representative prior to welding.

4. Welded Surface: Clean and dry, no adhesive within lap areas.

5. Machine Welding:

a. Use manufacturer’s automatic welding equipment to machine weld seams.

b. Follow manufacturer’s instructions and observe local codes for electric supply, grounding, and over-current protection.

c. Automatic welding machines require 218 to 2230 volts at 30 amps.

d. Use of a portable generator is recommended.

6. Hand Welding: Complete hand welded seams in three stages. Allow equipment to warm up for at lest one minute prior to start of welding.

a. Tack weld lap every 3 feet to hold seam in place.

b. Weld back edge of lap with a thin, continuous weld to prevent loss of hot air during final welding.

c. Insert hot air nozzle into lap, keeping welding equipment at 45 degree angle to side lap.

1) When proper welding temperature is reached and material starts to flow, apply hand roller at a right angle to welding gun and press lightly.

2) Use 1-1/2 inch wide nozzle for straight laps.

3) Use 3/4 inch wide nozzle for corners and compound connections.

7. Test lap edges with probe to verify seam weld continuity. Apply lap sealant to seal cut edges of sheet membrane.

VAPAHCS Palo Alto, CA

07 54 23 - 9

8. Verify field strength of seams a minimum of twice daily and repair seam sample areas.

9. Repair tears, voids, and lapped seams in roofing that does not comply with requirements.

K. Spread sealant bed over deck drain flange at roof drains and securely seal membrane roofing in place with clamping ring.

3.4 BASE FLASHING INSTALLATION

A. Install sheet flashings and preformed flashing accessories and adhere to substrates according to membrane 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.

3.5 TPO COATED SHEET METAL FLASHING

A. Install in accordance with roofing manufacturer’s instructions and Section 07 60 00, FLASHING AND SHEET METAL.

3.6 INTERLOCKING WALKWAY PAVER INSTALLATION

A. Install interlocking walkway pavers where indicated on Drawings.

B. Install interlocking walkway pavers in accordance with TPO membrane roofing manufacturer’s printed instructions.

3.7 LIGHTWEIGHT CONCRETE PAVERS

A. Install lightweight concrete pavers in accordance with TPO membrane roofing manufacturer’s printed instructions.

B. Install slip sheet of reinforced membrane or two layers of protective mat under pavers. Extend protective layer a minimum of 50 mm (2 inches) on each side of pavers.

C. Install pavers with butt joints in running bond with not less than one half length units at ends.

1. Stagger end joints; generally locate joints near midpoint of adjacent rows, except where end joints occur in valleys. Miter end joints to fit in valleys.

2. Cut to fit within 13 mm (1/2 inch) of penetrations.

VAPAHCS Palo Alto, CA

07 54 23 - 10

3.8 FIELD QUALITY CONTROL

A. Final Roof Inspection: Arrange for roofing system manufacturer's technical personnel to inspect roofing installation on completion.

B. Repair or remove and replace components of membrane roofing system where inspections indicate that they do not comply with specified requirements.

C. Additional inspections, at Contractor's expense, will be performed to determine compliance of replaced or additional work with specified requirements.

3.9 PROTECTING AND CLEANING

A. Protect membrane roofing system from damage and wear during remainder of construction period. When remaining construction will not affect or endanger roofing, inspect roofing for deterioration and damage, describing its nature and extent in a written report, with copies to Resident Engineer.

B. Correct deficiencies in or remove membrane roofing system that does not comply with requirements; repair substrates; and repair or reinstall membrane 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 - - -