07550 Modified Bituminous Membrane Roofing Attch 3.pdf

FA4417-10-R-0012 Amendment 2, Attachment 3 MS0610

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SECTION 07550: MODIFIED BITUMINOUS MEMBRANE ROOFING

PART 1 GENERAL

1.01 RELATED SPECIFICATION SECTIONS:

A. Section 01000 – GENERAL REQUIREMENTS

1.02 REFERENCES

A. The publications listed below form a part of this specification to the extent referenced. The publications are referred to in the text by the basic designation only.

1. AMERICAN SOCIETY FOR TESTING AND MATERIALS (ASTM)

a. ASTM D 41: (1994) Asphalt Primer Used in Roofing, Dampproofing, and Waterproofing

b. ASTM D 226: (1994) Asphalt-Saturated Organic Felt Used in Roofing and Waterproofing

c. ASTM D 312: (1995) Asphalt Used in Roofing

d. ASTM D 2170: (1995) Kinematic Viscosity of Asphalts (Bitumens)

e. ASTM D 4402: (1987; R 1991) Viscosity Determinations of Unfilled Asphalts Using the Brookfield

Thermosel Apparatus ASTM D 4586(1993) Asphalt Roof Cement, Asbestos-Free

f. ASTM D 4601: (1994) Asphalt-Coated Glass Fiber Base Sheet Used in Roofing

g. ASTM D 4897: (1994) Asphalt-Coated Glass-Fiber Venting Base Sheet Used in Roofing

h. ASTM D 5147: (1991) Sampling and Testing Modified Bituminous Sheet Material I. ASTM E 108: (1995) Fire Tests of Roof Coverings

2. FACTORY MUTUAL ENGINEERING AND RESEARCH CORPORATION (FM)

a. FM A/S4470: (1986; R 1992) Class I Roof Covers

b. FM P7825: (Current Edition) Approval Guide

3. UNDERWRITERS LABORATORIES INC. (UL)

a. UL RMSD: (Current Edition) Roofing Materials and Systems Directory

b. UL 790: (1983; R 1993) Fire Resistance of Roof Covering Materials

4. FEDERAL SPECIFICATIONS

a. FS HH-I-1972/2: Insulation Board, Thermal, Polyisocyanurate, Faced with Felt on Both Sides of the Foam

b. FS HH-I-1972/3 Insulation Board, Thermal, Polyisocyanurate Faced with Perlite Insulation Board on One Side and Asphalt/Organic Felt or Asphalt/Glass Fiber Felt on Other Side of the Foam

1.03 SUBMITTALS

A. Submit the following in accordance with section 01300 Submittals.

1. Manufacturer's Catalog Data

a. Modified bitumen sheet

b. Asphalt (sample)

c. Felts (sample)

d. Primer

e. Asphalt roof cement

f. Fasteners (sample)

g. Coating

h. Sample warranty certificate

2. Instructions: Include detailed application instructions and standard drawings altered as required by these specifications. Explicitly identify in writing, differences between manufacturer's instructions and the specified requirements.

a. Torches

b. Modified bitumen sheet

c. Asphalt

d. Felts

e. Primer

f. Asphalt roof cement

g. Fasteners

h. Coating

i. Flashings

j. Cold weather installation

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3. Statements: Certify that the manufacturer of the modified bitumen membrane meets requirements specified under paragraph entitled "Qualification of Manufacturer." Show evidence that products used within this specification are manufactured in the United States. Certify that the applicator meets requirements specified under paragraph entitled "Qualification of Applicator." Submit bill of lading when labels of asphalt containers do not bear the flash point (FP), finished blowing temperature (FBT), and equiviscous temperature (EVT). Submit complete material property test data for modified bitumen sheet material testing in accordance with ASTM D5147. Submit certification of minimum polymer content.

a. Qualification of manufacturer

b. Qualification of applicator

c. Bill of lading

d. Property test data

4. Reports: Submit the reports of testing required by ASTM D5147.

5. Records

a. Information card

b. Instructions to Government Personnel: Written Instructions to Government Personnel: Submit instructions meeting the requirements of paragraph entitled "Instructions to Government Personnel" and include copies of Material Safety Data Sheets for maintenance/repair materials.

1.04 QUALITY ASSURANCE

A. Qualification of Manufacturer: Modified bitumen sheet roofing system manufacturer shall have a minimum of 5 years experience in manufacturing modified bitumen roofing products.

B. Qualification of Applicator: Roofing system applicator shall be approved, authorized, or licensed in writing by the modified bitumen sheet roofing system manufacturer and shall have a minimum of three years experience as an approved, authorized, or licensed applicator with that manufacturer and be approved at a level capable of providing the specified warranty. The applicator shall supply the names and locations of 5 projects of similar size and scope that he has constructed using the manufacturer's roofing products submitted for this project within the previous three years.

C. Fire Safety: Complete roof covering assembly shall:

1. Have ASTM E 108 Class 1A or UL 790, Class A classification; and

2. Be listed as part of Fire-Classified roof deck construction in UL RMSD, or Class I roof deck construction in FM P7825.

3. UL approved components of the roof covering assembly shall bear the UL label.

D. Wind Uplift: Complete roof covering assembly shall be rated Class I- 90 in accordance with FM P7825 capable of withstanding an uplift pressure of 90 psf.

E. Preroofing Conference

1. After approval of submittals and before performing roofing and insulation work, including associated work, the Contracting Officer will hold a preroofing conference to review the following:

a. Drawings and specifications;

b. Procedure for on site inspection and acceptance of the roofing substrate and pertinent structural details relating to the roofing system;

c. Contractor's plan for coordination of the work of the various trades involved in providing the roofing system and other components secured to the roofing; and

d. Safety requirements.

The Contractor and personnel directly responsible for the installation of roofing and insulation, flashing and sheet metal work, mechanical and electrical work, and representative of the roofing materials manufacturer must attend 2. Preroofing conference. Before beginning roofing work, confirm in writing the resolution of conflicts among those attending the preroofing conference.

1.05 DELIVERY, STORAGE, AND HANDLING

A. Delivery: Deliver materials in manufacturers' original unopened containers and rolls with labels intact and legible. Mark and remove wet or damaged materials from the site. Where materials are covered by a referenced specification, the container shall bear the specification number, type, and class, as applicable.

Labels or bill of lading for roofing asphalt shall indicate asphalt type, FP, FBT, and EVT, that is, the temperature at which the viscosity is either 125 centistokes when tested in accordance with ASTM D 2170 or 75 centipoise when tested in accordance with ASTM D 4402. Deliver materials in sufficient quantity to allow work to proceed without interruption.

B. Storage: Protect materials against moisture absorption. Store roll materials on end on clean raised platforms or pallets one level high in dry locations with adequate ventilation, such as an enclosed building

07550 - 3 or closed trailer. Do not store roll materials in buildings under construction until concrete, mortar, and plasterwork is finished and dry. Maintain roll materials at temperatures above 50 degrees F for 24 hours immediately before application. Do not store materials outdoors unless approved by the Contracting Officer. Completely cover felts stored outdoors, on and off roof, with waterproof canvas protective covering. Do not use polyethylene sheet as a covering. Tie covering securely to pallets to make completely weatherproof and yet provide sufficient ventilation to prevent condensation. Do not store more materials on roof than can be installed the same day and remove unused materials at end of each days work. Distribute materials temporarily stored on roof to stay within live load limits of the roof construction.

C. Handling: Select and operate material handling equipment so as not to damage applied roofing. Prevent damage to edges and ends of roll materials.

1.06 ENVIRONMENTAL REQUIREMENTS

A. Do not install roofing system when air temperature is below 40 degrees F, during any form of precipitation, including fog, or when there is ice, frost, moisture, or any other visible dampness on the roof deck.

Provide manufacturer's printed directions for installation during cold weather conditions.

1.07 SEQUENCING

A. Coordinate the work with other trades to ensure that components which are to be secured to or stripped into the roofing system are available and that flashing and counter flashing are installed as the work progresses.

1.08 WARRANTY

A. Furnish the modified bitumen sheet roofing system manufacturer's "no-dollar-limit" warranty for the roofing system, including insulation, flashing, and accessories. The warranty shall run directly to the Government.

In no event shall the warranty period be less than 10 years from the date of the Government's acceptance of the work, notwithstanding roofing applicator or manufacturer's unpaid invoices for installation, supplies, or service. The warranty shall state that:

1. When within the warranty period the roofing system becomes non-watertight, splits, tears, blisters, or separates at the seams or shows any other evidence of excessive weathering, because of defective materials or workmanship, the repair or replacement of defective materials and correction of defective workmanship shall be the responsibility of the manufacturer;

2. When the manufacturer or the manufacturer's approved applicator fail to perform repairs within 72 hours of notification, emergency repairs performed by others will not void the warranty; and

3. Damage to the roofing system caused by sustained winds having a velocity of 75 mph or less is covered by the warranty.

B. Prior to issuance of the warranty, the roofing manufacturer’s representative shall inspect the installation and provide the Contracting Officer a written report as to the quality of the installation. All work identified as being not acceptable to the manufacturer’s representative, shall be corrected. Upon completion of the corrected work and acceptance by the manufacturer’s representative, the representative shall provide the Contracting Officer a written report indicating that all defective work has been corrected and that the warranty will be issued.

PART 2 PRODUCTS

2.01 DESCRIPTION OF ROOFING SYSTEM

A. APP or SBS Modified Bitumen Roof Membrane over Glass Fiber Base Sheet on Insulated Deck, Torched or set in Cold Liquid Applied Adhesive with Glass Fiber Ply Sheet and Granulated Cap Sheet Surface on Non-Nailable Substrate. Includes all base flashing, metal flashing and other components necessary for a complete installation.

1. APP Components: Quantity:

Type III or IV Asphalt per Manufacturer Requirements Asphalt Glass Fiber Base Sheet 1 ply Type III or IV Asphalt 25 lbs/100 sq. ft. between plies APP Smooth Surface Membrane 2 plies Granulated Cap Sheet 1 ply Mechanical Fasteners per Manufacturer’s Requirements

2. SBS Components: Quantity:

Type III or IV Asphalt per Manufacturer Requirements Asphalt Glass Fiber Base Sheet 1 ply Type III or IV Asphalt 25 lbs/100 sq. ft. between plies

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Asphalt Glass Fiber Ply Sheet 1 ply SBS Smooth Surface Membrane (Lightweight) 1 ply SBS Smooth Surface Membrane (Heavyweight) 1 ply Granulated Cap Sheet 1 ply Mechanical Fasteners per Manufacturer Requirements

2.02 MATERIALS

A. Asphalt: ASTM D 312, Type III or IV.

B. Modified Bitumen Sheet, Felts: Modified bituminous sheet materials shall be tested in accordance with

ASTM D5147 and contain a minimum of 10 percent polymer by weight.

C. Asphalt Glass Fiber Base Sheet (non-perforated) ASTM D 4601, Type II

D. Asphalt Glass Fiber Ply Sheet ASTMD2178, Type IV

E. Modified Bitumen Membrane Sheet Material

1. APP Modified Bitumen Membrane Sheet Material sheet shall be a prefabricated atactic polypropylene (APP) modified bitumen sheet, 160 mil thick minimum, monolithic polymer modified matrix containing bitumen, polypropylene, and other resins, with a layer of polyester sheet reinforcement.

2. SBS Modified Bitumen Membrane Sheet Material, Lightweight and Heavyweight. Modified bitumen sheet shall be a prefabricated styrene butadiene styrene (SBS) modified bitumen sheet, 160 mil thick minimum, a layer of polyester sheet reinforcement.

F. Base Flashing ASTMD5417

1. APP Modified Bitumen Base Flashing

2. SBS Modified Bitumen Base Flashing

G. Asphalt Roof Cement ASTMD4568 Type I for horizontal surfaces; Type II for vertical surfaces.

H. Polymer Modified Asphalt Roof Cement

I. Asphalt Primer ASTMD41

J. Fiber or Perlite Cant Strips ASTMC208

K. Fasteners: Provide non-corrosive fasteners as recommended by the modified bitumen sheet manufacturer's printed instructions and meeting the requirements of FM A/S4470. For felts, provide fasteners driven through metal discs, or one piece composite fasteners with heads not less than one inch in diameter or one inch square with rounded or 45 degree tapered corners.

1. Masonry or Concrete Walls and Vertical Surfaces: Provide hardened steel nails with flat heads, diamond shaped points, and mechanically deformed shanks not less than one inch long for securing felts, modified bitumen sheets, and metal Items to masonry or concrete walls and vertical surfaces.

Use power-driven fasteners only when approved in writing.

L. Metal Discs (Tin Caps): Flat non-corrosive fasteners as recommended by the modified bitumen sheet manufacturer's printed instructions and meeting the requirements of FM A/S4470; not less than 3 inches in diameter, when using screw type fasteners. Discs shall be formed to prevent dishing or cupping.

M. Walkboards: Roof walkways shall be smooth-surfaced reprocessed rubber, minimum 1/2 inch thick, or walkboards compatible with the modified bitumen sheet roofing and as recommended by the modified bitumen sheet roofing manufacturer.

N. Roof Insulation below Modified Bitumen Membrane System: Insulation shall be compatible with the membrane as recommended in modified bitumen manufacturer's printed instructions.

1. Polyisocyanurate Board: FS HH-I-1972/2 (Felt-faced) or FS HH-I-1972/1 (Foil-faced), except minimum compressive strength shall be 20 pounds per square inch (psi).

2. Composite Boards: FS HH-I-1972/3 (Polyisocyanurate-Perlite), Style 1 or 2; FS HH-I-1972/5

(Polyisocyanurate-Perlite); ASTM C 984 (Polyisocyanurate-Perlite).

3. Insulation Thickness:

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a. Air-conditioned buildings. As necessary to provide a thermal resistance (R value) of 30 or more for average thickness of tapered system. Thickness shall be based on the "R" value for aged insulation.

b. Non-air-conditioned buildings. As necessary to provide a thermal resistance (R value) of 12 or more for average thickness of tapered system. Thickness shall be based on the "R" value for aged insulation.

4. Tapered Roof Insulation: One layer of the tapered roof insulation assembly shall be factory tapered to a slope of not less than 1/4 inch per foot. Provide starter and filler blocks as required providing the total thickness of insulation necessary to meet the specified slope and thermal conductance. Mitered joints shall be factory fabricated and shall consist of two diagonally cut boards or one board shaped to provide the required slopes. Identify each piece of tapered insulation board by color or other identity coding system, allowing the identification of different sizes of tapered insulation board required to complete the roof insulation system.

PART 3 EXECUTION

3.01 EXAMINATION AND PREPARATION PRIOR TO INSTALLATION OF INSULATION.

A. Surface Inspection: Surfaces shall be clean, smooth, and dry. Check roof deck surfaces, including surfaces sloped to roof drains and outlets, for defects before starting work. The Contractor shall inspect and approve the surfaces immediately before starting installation. Prior to installing insulation, perform the following:

1. In the presence of the Contracting Officer perform the following surface-dryness test on concrete substrates:

a. Foaming: When poured on the deck, one pint of asphalt when heated in the range of 350 to 400 degrees F, shall not foam upon contact

b. Strippability: After asphalt used in the foaming test application has cooled to ambient temperatures, test coating for adherence. Should a portion of the sample be readily stripped clean from surface, do not consider surface to be dry and do not start application. Should rain occur during application, stop work and do not resume until surface has been tested by method above and found dry.

B. Surface Preparation: Correct defects and inaccuracies in roof deck surface to eliminate poor drainage and hollow or low spots and perform the following:

1. Install wood nailers the same thickness as insulation at eaves, edges, curbs, walls, and roof openings for securing cant strips, gravel stops, and flashing flanges.

3.02 INSULATION INSTALLATION

A. Apply insulation in two layers with staggered joints when total required thickness of insulation exceeds 1/2 inch. Lay insulation so that continuous longitudinal joints are perpendicular to direction of felts for the built-up roofing, as specified in Section 07550, "Modified Bituminous Membrane Roofing", and end joints of each course are staggered with those of adjoining courses. When using multiple layers of insulation, joints of each succeeding layer shall be parallel and offset in both directions with respect to layer below.

Keep insulation 1/2 inch clear of vertical surfaces penetrating and projecting from roof surface.

1. Installation Using Asphalt: Firmly embed each layer in solid asphalt mopping; mop only sufficient area to provide complete embedment of one board at a time. Provide 20 to 35 lbs. of asphalt per 100 square feet of roof deck for each layer of insulation. Apply asphalt when temperature is within plus or minus 25 degrees F of EVT. Do not heat asphalt above asphalt's FBT or 525 degrees F, whichever is less, for longer than 4 consecutive hours. Use thermometers to check temperatures during heating and application.

2. Installation Using Only Mechanical Fasteners; Secure total thickness of insulation with penetrating type fasteners.

3. Special Precautions for Installation of Foam Insulation

a. Polyisocyanurate Insulation: Where Polyisocyanurate foam board insulation is provided, install 3/4 inch thick expanded Perlite board insulation over top surface of foam board insulation. Stagger joints of insulation with respect to foam board insulation below.

4. Cant Strips: Where indicated, provide cant strips at intersections of roof with walls, parapets, and curbs extending above roof. Wood cant strips shall bear on and be anchored to wood blocking. Fit cant strips flush against vertical surfaces. Where possible, nail cant strips to adjoining surfaces.

Where cant strips are installed against non-nailable materials, install in heavy mopping of asphalt or set in a heavy coating of asphalt roof cement.

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5. Tapered Edge Strips: Where indicated, provide edge strips in the right angle formed by junction of roof and wood nailing strips that extend above level of roof. Install edge strips flush against vertical surfaces of wood nailing strips. Where possible, nail edge strips to adjoining surfaces. Where installed against non-nailable materials, install in heavy mopping of asphalt or set in heavy coating of asphalt roof cement.

3.03 PROTECTION

A. Protection of Applied Insulation: Completely cover each day's installation of insulation with the finished roofing specified on same day. Do not permit phased construction. Protect open ends of each day's work with temporary water cutoffs, and remove when work is resumed. Protect open spaces between insulation and parapets or other walls and spaces at curbs, scuttles, and expansion joints, until permanent roofing and flashing are applied. Do not permit storing, walking, wheeling, or trucking directly on insulation or on roofed surfaces. Provide smooth, clean board or plank walkways, runways, and platforms near supports, as necessary, to distribute weight to conform to a 20-psf live load limit.

B. Damaged Work and Materials: Restore work and materials that become damaged during construction to original condition or replace with new materials.

3.04 EXAMINATION AND PREPARATION PRIOR TO INSTALLATION OF ROOFING

A. Ensure that the following conditions exist prior to application of the roofing materials:

1. Drains, curbs, cants, control joints, expansion joints, perimeter walls, roof penetrating components, and equipment supports are in place.

2. Surfaces are rigid, dry, smooth, and dry. Check roof deck surfaces, including surfaces sloped to roof drains and outlets, for defects before starting work and free from cracks, holes, and sharp changes in elevation. Joints in the substrate are sealed to prevent dripping of bitumen into building or down exterior walls.

3. The plane of the substrate does not vary more than 1/4 inch within an area 10 by 10 feet when checked with a 10 foot straight edge placed anywhere on the substrate.

4. Substrate is sloped as indicated to provide positive drainage.

5. Walls and vertical surfaces are constructed to receive counter flashing, and will permit nailing of the base flashing materials.

6. Treated wood nailers are fastened in place at eaves, gable ends, openings, and intersections with vertical surfaces for securing of felts, edging strips, gravel stops, and roof fixtures. Surface-applied nailers are the same thickness as the roof insulation.

7. Cants are securely fastened in place in the angles formed by walls and other vertical surfaces. The angle of the cant is 45 degrees and the height of the vertical leg is not less than nominal 4 inches.

Cants are constructed of treated wood or wood fiberboard roof insulation.

8. Venting is provided in accordance with the following:

a. Edge Venting: Perimeter nailers are kerfed across the width of the nailers to permit escape of gaseous pressure at roof edges.

9. Insulation boards are installed smoothly and evenly, and are not broken, cracked, or curled. Insulation is being roofed over on the same day the insulation is installed

3.05 PREPARATION

A. Protection of Property

1. Protective Coverings: Install protective coverings at paving and building walls adjacent to hoist and kettles prior to starting the work. Lap protective coverings not less than six inches, secure against wind, and vent to prevent collection of moisture on covered surfaces. Keep protective coverings in place for the duration of the roofing work.

a. Flame-Heated Equipment: Do not place flame-heated equipment on roof. Provide and maintain a fire extinguisher adjacent to flame-heated equipment and on the roof.

b. Open Flame Application Equipment: Torches and other open flame equipment shall be specifically designated for use in application of modified bitumen and approved by the modified bitumen sheet manufacturer. Open flame equipment shall not be ignited (burning) when left unattended. Provide and maintain a fire extinguisher adjacent to open flame equipment on the roof. Apply a base sheet, in accordance with modified bitumen sheet manufacturer's recommendations, to combustible substrates prior to torch-application of modified bitumen membrane. Specific requirements for fire watches and burn permits exist. These requirements will be outlined at the preroofing conference.

c. Electric-Heated Equipment: Provide adequate electrical service as required by manufacturer of electrical equipment to ensure against damage to equipment and property and to ensure proper application of roofing materials.

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2. Priming of Surfaces: Prime surfaces at the rate of 0.75 gallon per 100 sq. ft. or as recommended by modified bitumen sheet manufacturer's printed instructions and allow to dry.

a. Priming of Concrete and Masonry Surfaces: After surface dryness requirements have been met, coat concrete and masonry surfaces which are to receive base sheet and roofing materials uniformly with asphalt primer. Allow primer to dry prior to application of base sheet, roofing, and flashing.

b. Priming of Metal Surfaces: Prime flanges of metal edging strips, prior to stripping into roofing system in accordance with modified bitumen manufacturer's printed instructions and allow to dry.

3. Heating of Asphalt: Break up solid asphalt on a surface free of dirt and debris. Heat asphalt in kettle designed to prevent contact of flame with surfaces in contact with the asphalt. Kettles shall have visible thermometer and thermostatic controls set to the temperature limits specified herein. Keep controls in working order and calibrated. Use immersion thermometer, accurate within a tolerance of plus or minus 2 degrees F, to check temperatures of the asphalt frequently. If the temperature of the asphalt at the moment of application is below the minimum specified, take a field sample of the affected roofing, analyze the sample as specified herein, and replace with new material if the sample as specified herein, and replace with new material if deficiencies are disclosed. When temperatures exceed maximums specified, remove asphalt from the site. Do no permit cutting back, adulterating, or fluxing of asphalt.

3.06 APPLICATION

A. Apply roofing materials as specified herein unless approved otherwise by the Contracting Officer. Keep roofing materials dry before and during application. Do not permit phased construction. Complete application of roofing in a continuous operation. Begin and apply only as much roofing in one day as can be completed that same day. Maintain specified temperatures for asphalt. Modified Bitumen Base Sheet shall not remain exposed prior to application of the Modified Bitumen Cap Sheet unless approved by the Contracting Officer and supported by the manufacturer's standard written application instructions. Provide temporary roofing and flashing as specified herein prior to application of permanent roofing system.

1. Temporary Roofing and Flashing: Provide temporary roofing and flashing where considerable work by other trades, is be performed on the roof or where construction scheduling or weather conditions require protection of the building's interior before permanent roofing system can be installed. Do not install temporary roofing over permanently installed insulation. Provide rigid pads for traffic over temporary roofing.

2. Temporary Roofing Membrane: Install 2 plies of ply felt in accordance with the application procedures specified.

3. Temporary Flashing: Install temporary flashing consisting of one ply of ply felt. Place ply felt in a trowel coat of asphalt roof cement and cover with a trowel coat of asphalt roof cement.

4. Removal: Completely remove temporary roofing and flashing before continuing with application of the permanent roofing system.

B. Bitumen Stops: Provide bitumen stops at roof edges, openings, and vertical projections before hot mopped application of the roofing membrane (base sheet and modified bitumen). Do not provide sheet metal bitumen stops. Form bitumen stops of two 18-inch wide strips of organic felt conforming to ASTM D

226. ply felts. Attach nine inches of the width to the roof surface and extend 9 inches beyond the edge.

Apply first strip in a 9-inch wide layer of asphalt roof cement and, where nailers are provided, nail on 6 inch spacing 1/2 inch from the edge. Apply second strip in a 9-inch wide mopping of asphalt. Protect the free portion of each strip from damage throughout the roofing period. After the roofing plies are in place, fold the free portion of each strip over the roofing membrane and embed in a continuous coating of asphalt roof cement and secure with fasteners 3 inches o/c.

C. Base Sheet: Apply base sheets in shingle fashion in hot mopping of asphalt. On nailable substrates, mechanically fasten base sheet in conformance with FM requirements and membrane manufacturer's printed instructions. Where applicable, base sheet may be mechanically fastened in conjunction with insulation to the substrate, in accordance with membrane manufacturers printed instructions. Apply sheets in a continuous operation. Apply sheets with side laps at a minimum of 2 inches unless greater side lap is recommended by the manufacturer's standard written application instructions. Provide end laps of not less than 6 inches and staggered a minimum of 36 inches. Apply sheets at right angles to the roof slope so that the direction of water flow is over and not against the laps. Extend sheets approximately 2 inches above the top of cant strips at vertical surfaces and to the top of cant strips elsewhere. Trim felt to a neat fit around vent pipes, roof drains, and other projections through the roof.

Application shall be free of ridges, wrinkles, and buckles.

D. Hot-Mopping of Base Sheets: Provide hot asphalt for embedding of base sheets, including modified bitumen base sheet, to the insulation or substrate. Apply base sheets immediately following application of

07550 - 8 hot asphalt. Do not work ahead with asphalt. Asphalt shall be completely fluid, with mop temperatures within the specified EVT range, at the instant base sheets come into contact with asphalt. Application of bitumen between plies shall be such as to provide full, continuous, uniform coverage and complete penetration of asphalt into the sheet above and below. Embed sheets in asphalt. As sheets are being rolled into hot asphalt, immediately and thoroughly squeegee, roll, or broom down to eliminate trapped air and to provide tight, smooth laminations without wrinkles, buckles, kinks, and fish mouths. Completed system shall be free of air pockets and blisters.

1. Temperature Limitations for Asphalt: Heat and apply asphalt at the temperatures specified below unless specified otherwise by manufacturer's printed application instructions. Use thermometer to check temperature during heating and application. Have kettle attended constantly during heating process to ensure specified temperatures are maintained. Do not heat asphalt above its FBT. Do not heat asphalt between 500 and 525 degrees for longer than four consecutive hours. Do not heat asphalt to the flash point (FP). Apply asphalt and embed base sheets when temperature of asphalt is within plus or minus 25 degrees F of the equiviscous temperature (EVT). Before heating and application of asphalt refer to the asphalt manufacturer's label or bill of lading for FP, FBT, and EVT of the asphalt used.

E. Modified Bitumen Sheets: Sheets shall be watertight and visually free of pinholes, particles of foreign matter, undispersed raw material, or other manufacturing defects that might affect serviceability. Edges of seams shall be straight and flat so that they may be seamed to one another without forming fish mouths or wrinkles.

1. Modified Bitumen Sheets: Install in strict accordance with manufacturer’s written instructions.

Manufacturer’s written instructions shall generally conform to the following:

a. Solid mop top surface of base sheet with hot asphalt at the rate of 25 pounds per 100 sq. ft. and embed one layer of roofing membrane into hot asphalt. Torch or apply cold liquid adhesive to fully adhere modified bitumen sheets to the base sheet. Unroll sheets set in place with minimum 3-inch side laps and minimum 6-inch end laps. Stagger end laps a minimum of 36 inches. Back mop end laps. Apply roofing in a continuous application. Start installation at the low point of the roof and progress to the high point. Provide tight, smooth laminations without wrinkles, ridges, buckles, kinks, and fishmouths. Completed system shall be free of air pockets, blisters, ridges, fishmouths, and open laps. After membrane has been adhered to substrate, check laps with a hot trowel to ensure laps are fully adhered. At areas where full adhesion of the laps are not obtained, reheat or trowel into place so that adhesion of the entire lap is accomplished.

F. Flashings: Apply modified bitumen sheet flashing in the angles formed where the roof deck abuts walls, curbs, ventilators, pipes, and other vertical surfaces, in accordance with membrane manufacturer's printed application instructions and where necessary to make the work watertight. Metal flashing collars and cap flashings are specified under Section 07600, "Flashing and Sheet Metal." Do not set metal flashing in hot asphalt.

G. Roof Walkways: Install asphalt plank roof walkways, where indicated, for traffic areas and for access to mechanical equipment, in accordance with the modified bitumen sheet roofing manufacturer's printed instructions.

H. Fire Watch: Provide fire watch during torch application and continue for one hour after completion of torch application. Provide at least two 2 1/2-gallon containers of water and two 15-pound CO2 extinguishers for use during the fire watch.

I. Clean Up: Remove debris, scraps, containers and other rubbish and trash resulting from installation of the roofing system from job site each day.

J. Protection of Applied Roofing Against Moisture Absorption: At the end of the day's work and when precipitation is imminent, protect applied modified bitumen roofing system as follows.

1. Water Cutoffs: Straighten insulation line using loose-laid cut insulation sheets and seal the terminated edge of modified bitumen roofing system with two full width strips of roofing felt set in and coated with asphalt roof cement. One-half width of the strips shall extend up and over the finished roofing and the other half-width extended out onto the bare deck unless recommended otherwise in membrane manufacturer's printed application instructions. Pull membrane free or cut to expose the insulation when resuming work, and remove the insulation sheets used for fill-in.

a. Temporary Flashing for Permanent Roofing: Provide temporary flashing at drains, curbs, walls and other penetrations and terminations of roofing sheets until permanent flashings can be applied. Temporary flashings shall consist of one ply of ply felt applied in a trowel coat of asphalt

07550 - 9 roof cement applied to a primed surface, and finished with a surface coat of asphalt roof cement.

Remove temporary flashing before applying permanent flashing.

b. Temporary Walkways, Runways, and Platforms: Do not permit storing, walking, wheeling, and trucking directly on applied roofing materials. Provide temporary walkways, runways, and platforms of smooth clean boards or planks as necessary to avoid damage to applied roofing materials, and to distribute weight to conform to indicated live load limits of roof construction. Use rubber-tired equipment for roofing work.

3.07 FIELD QUALITY CONTROL

A. Perform field-tests in the presence of the Contracting Officer. Notify the Contracting Officer one day before performing tests.

1. Test for Surface Dryness Before application of base sheets and starting work on the area to be roofed, perform test for surface dryness in accordance with the following:

a. Foaming: When poured on the surface to which felts are to be applied, one pint of asphalt when heated in the range of 350 to 400 degrees F, shall not foam upon contact.

b. Strippability: After asphalt used in the foaming test application has cooled to ambient temperatures, test coating for adherence. Should a portion of the sample be readily stripped clean from the surface, do not consider the surface to be dry and do not start application. Should rain occur during application, stop work and do not resume until surface has been tested by the method above and found dry.

c. Samples of Modified Bitumen Roofing: Take 4-inch by 40-inch cut samples across width of modified bitumen sheets as directed by the Contracting Officer. Cut samples will be examined by the Contracting Officer for specified number of plies, proper lap width, complete lap seal, full uniform asphalt application and adhesion, full bond between plies, harmful foreign materials, presence of moisture, and wet insulation.

d. Correction of Deficiencies: Where any form of deficiency is found, additional cut samples shall be taken as deemed necessary by the Contracting Officer to determine the extent of the deficiency and corrective actions shall be as directed by the Contracting Officer.

e. Instructions to Government Personnel: Furnish written and verbal instructions on proper maintenance procedures to designated Government personnel. Furnish instructions by a competent representative of the modified bitumen membrane manufacturer and include a minimum of 4 hours on maintenance and emergency repair of the membrane. Include a demonstration of membrane repair, and give sources of required special tools. Furnish information on safety requirements during maintenance and emergency repair operations.

3.08 INFORMATION CARD

A. For each roof, furnish a typewritten card, laminated in plastic and framed for interior display, or a photoengraved 0.032-inch thick aluminum card for exterior display. Card shall be 8 1/2 by 11 inches minimum and shall contain the information listed on Form 1 located at end of this section. Install card near point of access to roof, or where indicated.

07550 - 10

FORM 1, ROOFING SYSTEM DESCRIPTION

1. Location ______________________________ 2. Bldg. Name __________________________

3. Bldg. No. ________ 4. Roof Area (SF) ____________ 5. Contract No. ___________________

6. New Construction: ( ) Yes ( ) No 7. Deck Slope: _______________________________

8. Type of Deck:

( ) Metal ( ) Wood Plank or Plywood ( ) Cast-In-Place Concrete ( ) Other ( ) Precast/Prestressed Concrete

9. Type of Insulation Board:

( ) Polyisocyanurate ( ) Polyisocyanurate/Composite

10. Insulation Manufacturer: _________________________________________________________

11. Insulation Thickness: ___________________________________________________________

12. Vapor Treatment: Total coverage ( ) Yes ( ) No ( ) No Vapor Retarder ( ) Bituminous Vapor Retarder ( ) One Way Roof Vents ( ) Laminated Kraft Paper ( ) Other

13. Vapor Treatment Manufacturer(s): _________________________________________________

14. Roofing Type:

( ) Modified Bitumen

15. Roofing Manufacturer: __________________________________________________________

16. Roofing Installer/Warrantor: ______________________________________________________

17. Roofing Application Method:

( ) Torched ( ) Cold Applied

18. Warranty Period: From __________________________ To __________________________

19. Warranty Serial Number: ________________________________________________________

20. Date Roofing Completed: ______________________ 21. Inspector: _____________________

22. Prime Contractor Name/Address: __________________________________________________

Signature: __________________________________________ Date: _______________________

07550 - 11

INSTRUCTIONS FOR FORM 1 (Do Not Post)

1. Location: Name of activity as shown on contract.

2. Bldg. Name: As shown on contract or as provided by Contracting Officer.

3. Bldg. Number: As provided by Contracting Officer.

4. Roof Area: Area in square feet of roof for which deck insulation, membrane, etc. are the same. A separate form is required if any part of roof system is different over other areas of the roof.

5. Contract Number: As shown on the contract.

6. Show deck slope.

7. Deck: Check appropriate block.

8. Type of Insulation Board: Check appropriate block.

9. Show minimum thickness of installed insulation.

10. Vapor Treatment: Check appropriate blocks.

11. Show vapor treatment system manufacturer's name.

12. Roofing Type: Check appropriate block.

13. Show roofing manufacturer's name.

14. Roofing Installer' or Contractor's name.

15. Roofing Application Method: Check appropriate block.

16. Warranty Period: Insert start and end dates.

17. Show the Contracting Officer accepted date roofing. Warranty period begins on this date.

18. Show Government Inspector's name.

19. Prime Contractor Name/Address/Signature: Must be signed and dated by an official of contracting firm.

07550 - 12

APPENDIX A

TEST METHODS FOR DETERMINING PROPERTIES OF PREFABRICATED MODIFIED BITUMINOUS

MEMBRANE FOR ROOFING

(1) Breaking Strength and Ultimate Elongation: Test 5 specimens 1.97 inch wide by 5.91 inch long in the machine and cross-machine directions in accordance with ASTM D412. Use grips at least 1.97 inch wide initial grip separation of 3.15 inch, the grip separation speed of 0.33 inch/sec. The tensile strength and ultimate elongation shall be as defined in ASTM 412.

(2) Load Strain Product: The breaking strength and ultimate elongation of the membrane is determined as specified in the above paragraph "Breaking Strength and Ultimate Elongation." The breaking strength is multiplied by the ultimate elongation and expressed as percent. The resultant coefficient is the load strain product.

(3) Water Resistance: The test is conducted in part in accordance with ASTM D 570 except as described otherwise below. Condition three specimens 3.94 inch by 3.94 inch in accordance with ASTM D 618 procedure A. Determine the mass of the conditioned specimens and measure the dimensions in the machine and cross-machine directions at three locations. Immerse in distilled water at 122 degrees F for 5 days, then immerse in water at room temperature for 5 minutes to cool. Remove specimens from the water, blot off all surface water with a dry cloth, leave in standard laboratory atmosphere for 15+ 0.2 minutes for granule surfaced membrane heat in an oven operated at 221 degrees F for 15 minutes) cool and reweigh. Determine the conditions at the same locations previously measured. Calculate the mass of water absorbed in grams and the dimensional change as percent of original dimension.

(4) Low Temperature Flexibility: Cut 5 membrane specimens approximately 5.91 inch by 3.04 inch. Prepare a wooden mandrel using a hardwood block approximately 5.91 inch high by 5.91 inch in length and 1.91 inch thick. Place the mandrel and the specimens in a low temperature chamber maintained at a temperature of 22 degrees F. After 2 hours in the cold chamber bend the specimens through 90 degrees over the rounded edge of the wooden mandrel. The bending rate shall be uniform and done in 5 seconds.

Conduct the bend test within the low temperature environment with the bottom surface of the membrane down on the mandrel. Examine the bent area immediately for cracks. Place the specimen on a filter paper previously impregnated with phenolphthalein, which in turn is placed on insulation and a steel plate for support. Place a 1.18-inch minimum diameter by 23.62 inch in length glass cylinder upright on the specimen, centered over the bent area. Seal the glass cylinder to the specimen with one component silicone waterproof mastic sealant. Fill the glass cylinder to the 19.7-inch level with water, which contains 5 percent by mass carbonate of soda. Allow the filled glass cylinder to stand for 16 hours and examine the filter paper for any evidence to water leakage through the membrane test area. If leakage occurs the filter paper will become colored red. If leakage occurs the membrane is considered to fail the watertightness test. Four samples out of five shall pass the test.

(5) Accelerated Weathering: Expose five 1.97 inch wide by 5.91 inch specimens to 1080, two hour cycles in a water-cooled Xenon-Arch Type B apparatus as described in ASTM D 2565. Alternatively the exposure may be carried out in a twin enclosed carbon-arc lamp, Type D Weather-o-meter as described in ASTM G23 using the same one-hour arc, one-hour water cycle used for the Xenon-Arc. In case of dispute, the preferred method shall be the Xenon-Arc Weather-o-meter Method. The apparatus shall be operated on a cycle of one-hour radiation only followed by one-hour water spray only. After 1080 cycles (90 days) exposure, examine the specimens for evidence of cracking and blistering. Condition the specimens in accordance with ASTM D 618, procedure A and perform the breaking strength and ultimate elongation tests.

NOTE: Test procedures are derived in part from Canadian General Standards Board Publication 37-GP-56N standard for Membrane, Modified Bituminous, Prefabricated, and Reinforced for Roofing.

END OF SECTION