B09_Amd0001_Attach4_2009RoofReplaceSpec_0001.pdf

Medford Interagency Office MODIFIED BITUMINOUS MEMBRANE ROOFING

Roof Replacement Project 07550 - 1

SECTION 07550

MODIFIED BITUMINOUS MEMBRANE ROOFING

PART 1 - GENERAL

1.1 SECTION INCLUDES

A. Provide all labor, equipment, and materials to remove the existing roofing down to the roof deck and dispose of materials in a legally designated landfill. Correct any damaged decking. Install over the properly prepared substrate a new roofing system including:

1. a tapered isocyanurate insulation system sloped per drawings.

2. plywood overlay board;

3. four plies of type IV fiberglass ply sheet in hot asphalt;

4. modified SBS/SIS (Styrene Butadiene Styrene/ Styrene Isoprene Styrene) with the use of recycled tire crum rubber content;

5. gravel surface;

6. with steel flashing assembly set in hot asphalt.

B. Related Sections:

1. Section 01009 – General Requirements and Information

2. Section 01300 – Submittals

3. Section 01740 – Warranty Requirements

4. Section 06100 - Rough Carpentry

5. Section 07220 - Roof Deck and Insulation

6. Section 07565 - Preparation for Re-Roofing

7. Section 07620 – Sheet Metal Flashing and Trim

1.2 REFERENCES

A. American Society of Civil Engineers (ASCE):

ASCE 7-02, Minimum Design Loads for Buildings and Other Structures.

B. American Society for Testing and Materials (ASTM):

1. ASTM D41, Specification for Asphalt Primer Used in Roofing, Damp-proofing and Waterproofing.

2. ASTM D312, Specification for Asphalt Used in Roofing.

3. ASTM D451, Test Method for Sieve Analysis of Granular Mineral Surfacing for Asphalt Roofing Products.

4. ASTM D1079, Terminology Relating to Roofing, Waterproofing and

Bituminous Materials.

Roof Replacement Project 07550 - 2

5. ASTM D1227, Specification for Emulsified Asphalt Used as a Protective

Coating for Roofing.

6. ASTM D1863, Specification for Mineral Aggregate Used as a Protective

Coating for Roofing.

7. ASTM D2178, Specification for Asphalt Glass Felt Used as a Protective

Coating for Roofing.

8. ASTM D2822, Specification for Asphalt Roof Cement.

9. ASTM D2824, Specification for Aluminum-Pigmented Asphalt Roof Coating.

10. ASTM D4601, Specification for Asphalt Coated Glass Fiber Base Sheet Used in

Roofing.

11. ASTM D5147, Test Method for Sampling and Testing Modified Bituminous

Sheet Materials.

12. ASTM D6162, Specification for Styrene Butadiene Styrene (SBS) Modified

Bituminous Sheet Materials Using a Combination of Polyester and Glass Fiber

Reinforcements.

13. ASTM D6163, Specification for Styrene Butadiene Styrene (SBS) Modified

Bituminous Sheet Materials Using Glass Fiber Reinforcements.

14. ASTM E108, Test Methods for Fire Test of Roof Coverings.

C. Factory Mutual Research (FM):

Roof Assembly Classifications.

D. National Roofing Contractors Association (NRCA):

Roofing and Waterproofing Manual.

E. Underwriters Laboratories, Inc. (UL):

Fire Hazard Classifications.

F. Warnock Hersey (WH):

Fire Hazard Classifications.

1.3 SYSTEM DESCRIPTION

It is the intent of this specification to install a long-term, long-service-life, high quality four (4) ply built-up-roofing system that meets or exceeds all current NRCA guidelines as stated in the most recent edition of the NRCA Roofing and Waterproofing Manual.

Roof Replacement Project 07550 - 3

1.4 SUBMITTALS

A. Materials shall be submitted for approval prior to ordering via the procedures outlined in Section 1300 Submittals.

B. Product Data: Provide manufacturer’s technical product data for each type of roofing product specified. Include data substantiating that materials comply with specified requirements.

C. Samples: Submit four (4) samples of each product specified.

D. Manufacturer’s Installation Instructions: Submit manufacturer installation instructions and recommendations indicating special precautions required for installing the subject product.

E. Manufacturer’s Certificate: Manufacturer and Contractor shall certify in writing that roof system furnished is approved by Factory Mutual, Underwriters

Laboratories, Warnock Hersey or approved third party testing facility in accordance with ASTM E108, Class A for external fire and meets local or nationally recognized building codes.

F. Manufacturer’s Certificate: Manufacturer and Contractor shall certify that all supplied materials are manufactured in the United States and conform to requirements specified herein, are chemically and physically compatible with each other, and are suitable for inclusion within the total roof system specified herein.

Manufacturer and Contractor shall also certify at the time of contract acceptance and close-out in writing that the roof system components are installed and adhered together properly, and meet or exceed the requirements of FM 1-90 and FM

Approval Standard 4470.

G. Manufacturer’s Certificate: Contractor shall submit a certified copy of the roofing manufacturer’s ISO 9001 compliance certificate.

H. Manufacturer’s Certificate: Submit roofing system manufacturer’s written certification that the roofing system installer is an authorized installer in good standing and reputation for this specified four (4) ply built up roof system.

I. Sample 30-year manufacturer’s warranty for the entire roofing system, including flashings.

J. Provide the CO with a written statement that the manufacturer shall provide site inspection by an experienced, full time employee of the manufacturer every two (2) days that confirms that the project is being constructed as specified.

Roof Replacement Project 07550 - 4

K. Test Reports: Contractor shall retain the services of a third-party independent testing agency for the duration of this contract. The third-party independent testing agency shall submit all test reports directly to the CO with copies sent to the

Contractor. The third-party independent testing agency shall include in their reports the determination whether or not the modified bituminous sheet roofing complies with ASTM D5147.

1. Each test report shall indicate the percentage of adherence for each layer of the four (4) ply roofing system.

2. Each test report shall indicate the percentage and size of voids between each layer of the four (4) ply roofing system. The size of voids shall be expressed in square centimeters and the nomenclature common to the third-party independent testing agency.

3. Contractor shall comply with the testing requirements of this specification section and SECTION 1009.1.06.

L. Design Loads: Contractor shall submit four (4) copies of the manufacturer's minimum design load calculations according to ASCE 7-02, Method 2 for

Components and Cladding, sealed by a registered professional engineer employed by the system manufacturer as a full-time staff engineer. In no case shall the design loads be taken to be less than those detailed in article 1.14 of this specification.

1.5 QUALIFICATIONS

A. Manufacturer: The manufacturer of the various components comprising a four (4) ply built-up-roof system shall be a company specializing in manufacturing the products specified in this section with a longstanding record of satisfactory performance and documented experience, and hold a current ISO 9001 certification.

B. Installer: The Contractor shall be a company specializing in modified bituminous roofing installation with a longstanding record of satisfactory performance and demonstrated experience in built-up-roofing experience.

C. Installer’s Field Supervision: The Contractor shall maintain a full-time

Supervisor/Foreman on job site during all phases of roofing work and at any time roofing work is in progress. The Supervisor/Foreman shall maintain proper supervision of workmen at all times. The Contractor shall maintain a copy of the specifications and drawings in the possession of the Supervisor/Foremen and on the roof at all times.

1.6 PRE-INSTALLATION CONFERENCE

A. Pre-Work Conference: Contractor shall comply with the following requirements and those listed in specification Section 01009 Part 3. The CO will convene a pre-work conference after award and prior to issuing a Notice to Proceed.

Roof Replacement Project 07550 - 5

B. Required Attendees: The installer of each component of associated work; installers of deck or substrate construction to receive roofing work; installers of rooftop units and other work in and around roofing which must precede or follow roofing work

(including mechanical work if any); roofing system manufacturer’s representative;

the CO; the CO’s technical representative; and other representatives directly concerned with performance of the Work, including and not limited to the third-party testing agencies and governing authorities.

C. Objectives of conference to include:

1. Review foreseeable methods and procedures related to roofing work, including set up and mobilization areas for stored material and work area.

2. Tour representative areas of roofing substrates (decks) inspect and discuss condition of substrate, roof drains, curbs, penetrations and other preparatory work.

3. Review structural loading limitations of deck and inspect deck for loss of flatness and for required attachment.

4. Review roofing system requirements (drawings, specifications and other contract documents).

5. Receive submittals.

6. Review and finalize construction schedule related to roofing work and verify availability of materials, installer’s personnel, equipment and facilities needed to make progress and avoid delays.

7. Confirm understanding of the contract requirement that the Contractor shall not remove (tear-off) any amount of existing roofing and flashing material that cannot be replaced in the same day.

8. Review required inspection, testing, certifying and material usage accounting procedures.

9. Review weather and forecasted weather conditions and procedures for coping with unfavorable conditions, including possibility of temporary roofing.

10. Review notification procedures for weather or non-working days.

11. Record discussion of conference including decisions and agreements (or disagreements) reached and furnishes copy of record to each party attending.

If substantial disagreements exist at conclusion of conference, determine how disagreements will be resolved and set date for reconvening conference.

1.7 DELIVERY, STORAGE AND HANDLING

A. Deliver products to site with seals and labels intact, in manufacturer’s original containers, dry and undamaged.

B. Store and handle roofing sheets in a dry, well-ventilated, weather-tight place to ensure no possibility of significant moisture exposure. Store rolls of felt and other sheet materials on pallets or other raised surface. Stand all roll materials on end.

Cover roll-goods with a canvas tarpaulin or other breathable material (not polyethylene).

Roof Replacement Project 07550 - 6

C. Do not leave unused materials on the roof overnight or when roofing work is not in progress unless protected from weather and other moisture sources.

D. Any and all material and products exposed to weather and/or moisture prior to its full installation shall not be used. The Contractor shall remove such rejected material and products from the jobsite the same day. At no time shall these rejected materials and products be used as part of this contract’s construction.

E. It is the responsibility of the contractor to secure all material and equipment on the job site. If any material or equipment is stored on the roof, the contractor is responsible for ensuring that the structural capacity of the roof and the integrity of the deck are not compromised at any time. Damage to the structure and/or the deck caused by the Contractor will be the sole responsibility of the Contractor and will be repaired or replaced at Contractor’s expense.

1.8 MANUFACTURER’S INSPECTIONS

When the project is in progress, the roofing system manufacturer shall provide the following:

1. Keep the CO informed as to the progress and quality of the work they have personally observed.

2. Provide periodic job site inspections.

3. Report to the CO in writing after each job site inspection whether the application procedures conform to the manufacturer’s requirements and recommendations, whether any unacceptable application procedures were observed, whether any communications were made to the Contractor or the CO, and whether the

Contractor failed or refused to correct unacceptable practices.

4. Confirm at the completion of the contract that the manufacturer has observed no application procedures in conflict with the manufacturer’s requirements and recommendations, other than those that may have been previously reported and corrected.

1.9 PROJECT CONDITIONS

A. Proceed with roofing work only when existing and forecasted weather conditions will permit work to be installed in accordance with these contract requirements and drawings, manufacturer’s recommendations, and warranty requirements.

B. Do not apply roofing insulation or membrane to damp deck surface.

C. Do not expose materials vulnerable to water or sun damage in quantities greater than can be weatherproofed during the same day.

Roof Replacement Project 07550 - 7

1.10 SEQUENCING AND SCHEDULING

A. Sequence installation of modified bituminous sheet roofing with related units of work specified in other sections to ensure that roof assemblies including roof accessories, flashing, trim and joint sealers are protected against damage from effects of weather, corrosion and adjacent construction activity.

B. Fully complete all modified bituminous membrane roofing field assembly work each day. Phased construction shall not be accepted.

C. See specification Section 01009 for the required sequencing of each roof area.

1.11 WARRANTY

A. Upon completion of installation and acceptance by the CO, the Contractor and

Manufacturer shall supply to the CO with an executed warranty in accordance with the approved sample warranty.

B. Contractor shall submit a minimum of a five (5)-year labor warranty to the CO with a copy to the membrane manufacturer. The roofing materials manufacturer shall give the Bureau of Land Management a Thirty (30) year warrant against roofing system leaks and failure due to defective materials and workmanship. These individual warranties shall be supplied at no extra charge to the Bureau of Land

Management.

1.12 PRODUCT OPTIONS AND SUBSTITUTIONS

A. Alternative roofing systems and/or alternative materials may not be included in bids. Bids must be based on the specified systems and materials for consideration.

B. Substitutions: Alternative roofing systems and/or materials may be proposed after award. Comply with all requirements for substitutions in specification Section

01300.

1.13 QUALITY ASSURANCE

A. All systems submitted to meet the specified material must be accompanied by a copy of manufacturer’s standard specification section. Those specifications and shop drawings shall be signed and sealed by a professional architect or engineer licensed in the state of Oregon. Roof system requests containing specifications without licensed architect or engineer certification shall be considered non responsive and rejected. Stamped specifications must be included with the system submittal for all systems to be considered and/or approved by the CO.

B. The Contractor shall submit work experience and evidence of adequate financial responsibility. The CO reserves the right to inspect Contractor’s facilities in determining qualifications.

Roof Replacement Project 07550 - 8

1.14 DESIGN AND PERFORMANCE CRITERIA

A. Uniform Wind Uplift Load Capacity

Installed roof system shall withstand negative (uplift) design wind loading pressures complying with the following criteria. Attachment shall be installed exactly as given in article 3.3 of this specification.

a. Design Code: ASCE 7-02, Method 2 for Components and Cladding.

b. Category III Building with an Importance Factor of 1.15

c. Wind Speed: 90 mph d Ultimate Pullout Value: 730 pounds per each of the fasteners

e. Exposure Category: B

f. Design Roof Height: 47feet.

g. Minimum Building Width: 55 feet.

h. Roof Pitch: ½” inch per 4 foot.

i. Topographic Factor: 1.00

Roof Area Design Uplift Pressure:

Zone 1 - Field of roof 13.7 psf

Zone 2 - Eaves, ridges, hips, and rakes 23.6 psf

Zone 3 – Corners 34.5 psf

B. Snow Load: 25 psf.

PART 2 - PRODUCTS

2.1 DESCRIPTION

A. Ensure that all components are compatible with one another and that together they will produce a warrantable system that will function as designed.

B. Modified bituminous roofing work including but not limited to the following overall components. Material requirements are detailed in Sections 2.2 through 2.4.

1. Four (4) plies of glass fiber roofing felt bonded to prepared substrate with hot bitumen.

2. Membrane Flashing: Manufactured modified membrane roof termination/flashing system comprised of a flexible, tie-in membrane, factory-bonded within a watertight, mechanical seal to a sheet metal vertical flashing or fascia reveal profile. Use an elastomeric styrene-butadiene-styrene polymer high performance, strength and tear resistant non-woven rubber modified bitumen coating roofing membrane 2.0 mm (80 mils) thick.

Roof Replacement Project 07550 - 9

3. Aggregate Apply surfacing materials in the quantities specified two hundred

(200) pounds per roofing square for aggregate. Uniformly embed aggregate in a flood coat of hot bitument adhesive at a rate of two (2) gallons per roofing square coverage after felt flashings, tests, repairs, and corrective actions have been completed and approved to conform to ASTM D1863.

4. Flashings, rain drains, and accessories as required per plans.

5. Incidental auxiliary materials as required and recommended by standard industry practice for a complete job.

2.2 BITUMINOUS MATERIALS

A. Asphalt Primer: V.O.C. compliant, ASTM D41.

B. Asphalt Roofing Mastic: V.O.C. compliant, ASTM D2822, Type II.

C. Interply Adhesive: ASTM D312, Type IV.

D. Hot Bitumen

1. Softening Point 210°F - 225°F (99°C - 107°C)

2. Flash Point 500°F (260°C)

3. Penetration @ 77°F 15-25 units

4. Ductility @ 77°F 1.5 cm

2.3 SHEET MATERIALS

A. Felt Plies:

Fiberglass Felts: ASTM D2178, Type VI; membrane shall have elongation properties of 55 to 60 percent with a polyester reinforcement mat.

B. Membrane Flashing:

1. Manufactured modified membrane roof termination/flashing system comprised of a flexible, tie-in membrane, factory-bonded within a watertight, mechanical seal to a sheet metal vertical flashing or fascia reveal profile. Siliconized modified polyester, epoxy primer baked both sides, as approved by finish coat manufacturer.

Modified membrane is a 135 mil, Styrene-Butadiene-Styrene SBS (Styrene-

Butadiene-Styrene) rubber modified membrane reinforced with a dual fiberglass scrim.

Membrane Properties:

Tensile Strength (ASTM D5147)

2 in/min. @ 73.4 @ 3.6°F MD 210 lbf/in CMD 210 lbf/in

Tear Strength (ASTM D5147)

2 in/min. @ 73.4 @ 3.6°F MD 250 lbf CMD 250 lbf

Roof Replacement Project 07550 - 10

Elongation at Maximum Tensile (ASTM D5147)

2 in/min. @ 73.4 @ 3.6°F MD 6.0% CMD 6.0%

Low Temperature Flexibility (ASTM D5147):

Passes -20°F (-29°C)

Coating Properties:

Property Test Method SMP

Pencil ASTM D-3363 F-H

Hardness NCCA II-2

Bend ASTM D-4145 2-T

NCCA II-19

Cross-Hatch ASTM D-3359 no loss of

Adhesion adhesion

Gloss ASTM D-523 90+/-5%

(60° angle)

Reverse ASTM D-2794 no cracking or

Impact loss of adhesion

Nominal ASTM D-1005

Thickness

Primer 0.2 mils

Topcoat 0.8 mils

TOTAL 1.0 mils

2. Modified Membrane Properties:

TO EXCEED; ASTM D-6162, Type III Grade G

Tensile Strength (ASTM D-5147)

2 in/min. @ 73.4 @ 3.6°F MD 700 lbf/in CMD 750 lbf/in

Tear Strength (ASTM D-5147)

2 in/min. @ 73.4 @ 3.6°F MD 1300 lbf CMD 1400 lbf

Elongation at Maximum Tensile (ASTM D-5147)

2 in/min. @ 73.4 @ 3.6°F MD 6.0% CMD 6.0%

Low Temperature Flexibility (ASTM D-5147): Passes -30°F (-34°C)

Roof Replacement Project 07550 - 11

Reflectivity (DNS Method): 75-80%

C. Base Sheet: ASTM D4601, Type II; as recommended and furnished by the modified membrane manufacturer.

2.4 SURFACINGS

A. Top coat for embedding aggregate, two hundred (200) pounds per roofing square.

1. Hot Applied Flood Coat Adhesive: one-component, flexible, low odor, polyurea roof coating top coat. Performance Requirements:

a. Non-Volatile Content ASTM D2369, 89%

b. Density 9.85 lbs./gal.

c. V.O.C. Less than 126 grams/liter

d. Viscosity at 77 ºF Brookfield viscometer 60 poise

e. Flash Point ASTM D93 120ºF (41°C)

2. Hot applied asphalt per Section 2.2.D.

B. Roofing Aggregate: To conform to ASTM D-1863

Apply surfacing materials in the quantities specified two hundred (200) lbs. per roofing square for aggregate. Uniformly embed aggregate in a flood coat of cold adhesive at a rate of two (2) gallons per roofing square coverage after felt flashings, tests, repairs, and corrective actions have been completed and approved to conform to ASTM D1863.

2.5 RELATED MATERIALS

A. Rust Inhibitive Paint: As recommended and furnished by the membrane manufacturer for mechanical units and other metal surfaces to control and prevent surface rust.

B. Urethane Sealant: One-part, non-sag sealant as recommended and furnished by the membrane manufacturer for moving joints.

1. Tensile Strength (ASTM D412) 250 psi

2. Elongation (ASM D412) 950%

3. Hardness, Shore A (ASTM C920) 35

4. Adhesion-in-Peel (ASTM C920) 30 pli

C. Silicone Damp-Proofing: Transparent and colorless solution designed to damp-proof above grade masonry surfaces as recommended and furnished by the membrane manufacturer.

Roof Replacement Project 07550 - 12

1. Density @77°F 8.4 lb/gal min.

2. Viscosity (Zahn #2 cup) Typical 14 sec.

D. Butyl Tape: 100% solids, asbestos free and compressive tape designed to seal as recommended and furnished by the membrane manufacturer.

E. Pitch Pocket Sealer: Two part, 100% solids, self leveling, polyurethane sealant for filling pitch pans as recommended and furnished by the membrane manufacturer.

1. Durometer (ASTM D2240) 40-50 Shore

2. Elongation (ASTM D 412) 250%

3. Tensile Strength (ASTM D 412) 200 @ 100 mil

F. Fiber Cant: Continuous triangular cross section made of inorganic fibrous glass used as a cant strip as recommended and furnished by the membrane manufacturer.

G. Flashing Boot: Neoprene pipe boot for sealing single or multiple pipe penetrations adhered in approved adhesives as recommended and furnished by both the membrane and boot manufacturers.

H. Roof Drains: Drain system as indicated by the drawings.

I. Pitch pans, Rain Collar 24 gauge stainless steel. All joints should be welded/soldered watertight.

J. Drain Flashings should be 4lb (1.8kg) sheet lead formed and rolled.

K. Plumbing stacks should be 4lb (1.8kg) sheet lead formed and rolled.

PART 3 - EXECUTION

3.1 EXAMINATION

A. Verify that deck surfaces and project conditions are ready to receive work of this section.

B. Verify that deck is supported and secured to structural members.

C. Verify that deck is clean and smooth, free of depressions, projections or ripples.

D. Verify that adjacent roof substrate components do not vary more than 1/4 inch in height.

E. Verify that deck surfaces are dry and free of water. Verify that metal deck flutes are clean and dry.

Roof Replacement Project 07550 - 13

F. Confirm that moisture content does not exceed twelve (12) percent by moisture meter tests. On concrete deck pour a test patch of hot asphalt onto the deck. If it bubbles or foams, or does not adhere to the substrate when cool, the moisture levels are too high. Clean test area and allow to dry until moisture level meets these requirements.

G. Verify that openings, curbs, pipes, conduit, sleeves, ducts, and other items which penetrate the roof are set solidly, and that cant strips, nailing strips and reglets are set in place.

3.2 PREPARATION– CONCRETE DECK

Fill honeycombing and imperfections in deck surface with latex filler.

3.3 PREPARATION – STEEL DECK

A. Prepare metal deck per General Notes on Sheet A1-0.

B. Replace worn, damaged, or deteriorated gypsum board with new water-resistant gypsum board of similar thickness and secure with 1 ¼” long zinc coated steel self-tapping screws at 12’ on center each way.

C. Insure final prepared surface is secure, free of debris and defects.

3.4 GENERAL INSTALLATION REQUIREMENTS

A. Cooperate with manufacturer, inspection and test agencies engaged or required to perform services in connection with installing the roof system.

B. Protect other work from spillage of roofing materials and prevent materials from entering or clogging drains and conductors. Replace or restore other work damaged by installation of the modified bituminous roofing system.

C. Coordinate installation of roofing system components so that insulation and roofing plies are not exposed to precipitation or left exposed overnight. Provide cut-offs at end of each day’s work to cover exposed ply sheets and insulation with two (2) plies of #15 organic roofing felt set in full moppings of bitumen and with joints and edges sealed with roofing cement. Remove cut-offs immediately before resuming work. Contractor shall not remove (tear-off) any amount of roofing and flashing material that cannot be replaced in the same day.

D. Asphalt Bitumen Heating: Heat and apply bitumen in accordance with the

Equiviscous Temperature (EVT) Method as recommended by National Roofing

Contractors Association (NRCA). Do not raise temperature above minimum normal fluid-holding temperature necessary to attain EVT (plus 5°F at point of application) more than one (1) hour prior to time of application. Determine flash

Roof Replacement Project 07550 - 14 point, finished blowing temperature, EVT, and fire-safe handling temperature of bitumen either from information by manufacturer or by suitable test. Do not exceed recommended temperature limits during bitumen heating. Do not heat to a temperature higher than twenty five degrees (25°) below flash point. Discard and remove from the job-site bitumen that has been held at temperature exceeding

Finishing Blowing Temperature (FBT) for more than three (3) hours. Keep kettle lid closed except when adding bitumen.

E. Bitumen Mopping Rate:

1. Interply Mopping: Apply bitumen at the rate of approximately twenty five

(25) lb (11.3kg). of bitumen per roofing square.

2. Modified Membrane Mopping: Apply bitumen at the rate of approximately thirty (30) lb (13.6kg) of bitumen per roofing square.

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

G. Sequencing

1. Phased construction is not permitted nor allowed.

2. Complete the application of roofing plies, modified sheet and flashing in a continuous operation.

3. Contractor shall begin and apply only as much roofing in one day as can be completed that same day.

H. Broadcast minerals into the bleed out of bitumen while bitumen is at its recommended EVT temperature to achieve uniform color throughout.

3.5 INSULATION INSTALLATION

A. Deck type: See section 07220 - Roof Deck and Insulation.

B. Deck type: (Concrete) See section 07220 - Roof Deck and Insulation

3.6 FELT PLY INSTALLATION

A. Fiberglass Plies: Install four (4) fiberglass ply sheets in twenty five (25) pounds

(lbs) (11.3kg) per roofing square of bitumen shingled uniformly to achieve four plies over the entire prepared substrate. Shingle in direction of slope of roof to shed water on each area of roof. Do not step on felt rolls until asphalt has cooled. Cut and patch fish mouths per manufacturer’s recommendations.

B. Lap ply sheet ends and edges eight (8) inches (203mm). Stagger end laps twelve

(12) inches (304mm) minimum.

Roof Replacement Project 07550 - 15

C. Lightly broom in fiberglass plies to assure complete adhesion.

D. Extend plies six (6) inches (150mm) beyond top edges of cants at wall and roof projections and equipment bases, unless otherwise specified on the drawings.

E. Install base flashing ply to all perimeter and projection details after membrane application.

3.7 MODIFIED MEMBRANE APPLICATION

A. Solidly bond the modified membrane to the four felt plies and the base flashing layers with specified asphalt at the rate of thirty (30) lbs (11-13kg) per 100 square feet.

B. The modified membrane roll must push a puddle of hot asphalt in front of it with asphalt slightly visible at all side laps. Exercise care during application to eliminate air entrapment under the membrane.

C. Apply modified membrane rolls across the roof shingle-fashion as described in 3.6 above, with a minimum of four (4) inch (101mm) side laps and eight (8) inch

(203mm) end laps. Stagger the end laps [8 inches]. Apply the modified membrane in the same direction as the previous layers but stagger the laps so they do not coincide with the laps of the base layers.

D. Apply pressure to all seams to ensure that the laps are solidly bonded to substrate.

E. Apply asphalt no more than three (3) feet (0.9 meters) ahead of each roll being embedded.

F. Extend membrane a minimum of six (6) inches (150mm) beyond top edge of all cants in full hot asphalt moppings of the specified asphalt unless shown otherwise on the drawings.

3.8 FLASHING MEMBRANE INSTALLATION

A. Seal all curb, wall and parapet flashings with an application of mastic and mesh on a daily basis. Do not permit conditions to exist that will allow moisture to enter behind, around or under the roof or flashing membrane.

B. Prepare all walls, penetrations, and expansion joints shown on the drawings to be flashed with asphalt primer at the rate of one hundred (100) square feet per gallon.

Allow primer to dry tack free.

Roof Replacement Project 07550 - 16

C. Use the modified membrane as the flashing membrane. Adhere to the underlying base flashing ply with specified asphalt unless otherwise noted in these specifications. Nail off at a minimum of eight (8) inches (203mm) on center from the finished roof at all vertical surfaces.

D. Solidly adhere the entire sheet of flashing membrane to the substrate. Tops of all flashings that are not run up and over curb shall be secured through termination bar

6” and sealed at top.

E. Seal all vertical laps of flashing membrane with a four-course application of trowel-grade mastic and fiberglass mesh.

F. Coordinate counter flashing, cap flashings, expansion joints, and similar work with modified bitumen roofing work as specified in other sections.

G. Coordinate roof accessories, miscellaneous sheet metal accessory items, including piping vents and other devices with the roofing system work as specified in other sections.

H. Metal Edge System

1. Position the four base plies of the Built-Up modified roofing over the roof covering nailers completely, fastening eight (8) inches on center. Install membrane and cap sheet with proper material and procedure according to manufacturer’s recommendations.

2. Cant Dam: Install Cant Dam overlapping Cant a minimum of two (2) inches.

Fasten Cant Dam every three (3) inches on center through the top of nailer and outside face.

3. BUR or Modified Flashing: Prime Cant Dam at a rate of one hundred (100) square feet per gallon and allow to dry.

4. Strip in Cant Dam with base flashing membrane extending six (6) inches into roof field, followed with a cap sheet extending nine (9) inches into the roof field. Install membrane and cap sheet with proper material and procedure according to manufacturer’s recommendations.

5. Fascia Cover: Install fascia cover with splice plate under one end by pressing downward firmly until “snap” occurs and cover is engaged along entire length of miter. Field cut where necessary with fine tooth saw.

6. Sealant is to be placed between splice plates on metal edge pieces.

7. Install a second ply of modified flashing ply in bitumen over the base flashing ply, nine (9) inches on to the field of the roof.

I. Coping Cap:

1. Minimum flashing height is eight (8) inches (203mm) above finished roof height. Maximum flashing height is twenty four (24) inches (609mm). Refer

Roof Replacement Project 07550 - 17 to drawings for locations of flashing heights. Prime vertical walls at a rate of one hundred (100) square feet per gallon and allow to dry.

2. Set cant in bitumen. Run all field plies over cant a minimum of six (6) inches

150mm).

3. Install base flashing ply covering entire wall and wrapped over top of wall and down face with six (6) inches (150mm) on to field of the roof and set in hot asphalt. Nail membrane at eight (8) inches (203mm) on center.

4. Install a second ply of modified flashing ply in bitumen over the base flashing ply, nine (9) inches (228mm) on to the field of the roof. Apply a four-course application of mastic and mesh at all seams and allow to cure.

5. Install coping cap per manufacturer’s recommendations.

J. Roof and Overflow Drains:

1. Plug drain to prevent debris from entering plumbing; remove and replace roof/overflow drain fixture and fittings.

2. Taper insulation to slope toward the drain at least 2 percent over a horizontal distance of at least thirteen (13) inches (310 mm) from center of drain.

3. Run roof system plies over drain. Cut out plies inside drain bowl.

4. Set lead flashing at least twenty-four (24) inches square in a bed of mastic ¼ inch (6mm) thick . Run lead flashing into drain a minimum of two (2) inches

(50mm). Prime lead at a rate of one hundred (100) square feet per gallon and allow to dry.

5. Install a ply of the base flashing at least forty (40) inches square in bitumen.

6. Install a ply of the modified membrane at least forty eight (48) inches square in bitumen.

7. Install clamping ring and assure that all plies are under the clamping ring.

8. Remove drain plug and install new strainer.

K. Plumbing Stack

1. Minimum stack height is twelve (12) inches (304mm).

2. Install properly sized sleeves set in ¼ inch (6mm) thick bed of roof cement.

3. Provide a ¼ inch (6mm) air gap between and surrounding the sleeve and the plumbing stack to prevent condensation.

4. Install a two foot six inch square base flashing ply in bitumen covering the flanges of the sleeve.

5. Install a four foot square modified membrane in bitumen.

6. Run roof system over the entire surface of the roof up to the stack. Cut out for stack and seal the base of the stack with elastomeric sealant.

7. Turn sleeve top a minimum of two (2) inches (50 mm) vertically down inside of stack.

Roof Replacement Project 07550 - 18

3.9 APPLICATION OF SURFACING

A. Prior to installation of surface, obtain approval from roofing manufacturer as to work completed.

B. Aggregate Surfacing:

1. Apply aggregate at the rate of two hundred (200) lbs. per roofing square.

Uniformly embed aggregate in a flood coat of hot adhesive at a rate of two (2) gallons per roofing square.

2. Aggregate shall be dry and placed in a manner required to form a compact, solidly embedded overlay. To aid in proper embedment, lightly roll aggregate provided that there is no damage to the roofing membrane.

3.10 FIELD QUALITY CONTROL

A. Perform field inspection and testing as required under provisions of this section and

Section 01009 General Information and Requirements.

B. Correct defects or irregularities discovered during field inspection.

C. Require attendance of roofing and insulation materials manufacturers’ representatives at site during installation of the roofing system. A copy of the contract documents should also be on site and on the roof at all times.

D. The Contractor shall immediately correct any roof leakage during the construction of this project. If the Contractor does not respond within twenty four (24) hours of notification by the CO, the CO may hire a qualified contractor to repair the leak at the Contractor’s expense and without void to any warranty on the roofing system or its workmanship.

3.11 CLEANING

A. Remove bitumen adhesive drippings from all walls, windows, floors, ladders and finished surfaces.

B. In areas where finished surfaces are soiled by asphalt or any other sources of soiling caused by work of this section, consult manufacturer of surfaces for cleaning instructions and conform to their instructions.

C. Repair or replace defaced or disfigured finishes caused by work of this section.

Roof Replacement Project 07550 - 19

3.12 FINAL INSPECTION

A. At completion of roofing installation and associated work, the Contractor shall meet with the CO, installer, installer of associated work, roofing system manufacturer’s representative and other representatives directly concerned with performance of roofing system.

B. Walk roof surface areas of the building, inspect perimeter building edges as well as flashing of roof penetrations, walls, curbs and other equipment. List all items requiring correction or completion and furnish copy of list to each party in attendance.

C. The roofing system manufacturer and the Government reserve the right to request a thermographic scan of the roof during final inspection to determine if any damp or wet materials have been installed. The thermographic scan shall be provided at the

Contractor’s expense. If the results of the thermographic scan are positive for damp or wet materials, the Government may request core cuts through suspect sections of the roof.

D. If core cuts verify the presence of damp or wet materials, the Contractor shall repair the damaged areas at his own expense. If materials are dry and acceptable, the

Contractor shall repair the damaged areas at the Government’s expense.

E. Contractor shall repair or replace deteriorated or defective work found at time of inspection as required to a produce an installation which is free of damage and deterioration at time of Substantial Completion, is technically equivalent to an installation which had not been damaged and repaired, and fully warrantable under the terms of this Contract.

F. Contractor shall notify the CO upon completion of corrections.

G. Following the final inspection and any subsequent corrections, the CO shall provide written notice of acceptance of the installation to the Contractor and the roofing system manufacturer.

END OF SECTION