1352.011 Section 07 01 50.19 Preparation for Re-Roofing - Add 2.pdf

01-01-21

07 01 50.19 Addenda 2 - 1

SECTION 07 01 50.19

PREPARATION FOR RE-ROOFING – ADDENDA 2

PART 1 - GENERAL

1.1 SUMMARY

A. Section Includes:

1. Building 4: Complete roof removal down to the structural deck for new roof system installation.

2. Building 90: Roofing membrane and insulation removal down to the structural deck for new roof membrane installation.

B. Existing Roofing System:

1. Roof Areas 4A.1 – 4A.3

a. The roof membrane is Thermoplastic Polyolefin (TPO).

b. The insulation is 1-1/2” thick isocyanurate.

1) Additional tapered isocyanurate insulation is present on Roof

Area 4A.2.

c. The deck is 1 x 6 tongue and groove wood plank.

1) Roof Area 4A.1, slope is approximately 3/4” per foot and is in the deck.

2) Roof Area 4A.2, structural deck is flat.

3) Roof Area 4A.3, slope is approximately 1/2” per foot and is in the deck.

2. Roof Area 4B

a. The exposed roofing surface is asphalt shingle.

b. The underlayment sheet appears to be synthetic roofing underlayment.

c. The deck is 1 x 6 tongue and groove wood plank.

1) The roof slope is typically 7” per foot.

d. Batt insulation (R-19) is applied to the bottom of the deck.

3. Roof Areas 4C.1 & 4C.2

a. The roof membrane is Thermoplastic Polyolefin (TPO).

b. The insulation is 1-1/2” thick isocyanurate.

c. The deck is structural concrete.

1) Roof Area 4C.1, the structural deck is flat.

2) Roof Area 4C.2, the structural deck is sloped approximately

1/2" per foot.

4. Roof Area 4D

a. The roof membrane is Thermoplastic Polyolefin (TPO).

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b. Cores have not been taken in this Roof Area. Roof composition shall be assumed to match Roof Areas 4A.1-4A.3. Contractor to field verify conditions.

5. Roof Area 4E

a. Roof Area 4E is a skylight system.

6. Roof Areas 90A-90J

a. The roof membrane is modified bitumen with a granulated cap sheet.

b. The base flashings are bituminous.

c. The coverboard is 1/2” thick perlite.

d. The insulation is 1” thick isocyanurate.

e. The base sheet is asphalt impregnated felt.

f. The roof deck is lightweight concrete over a metal deck pan.

1) The roof slope is accomplished with varying thickness lightweight concrete. Roof slopes vary from 1/8” per foot to

1/4” per foot.

2) Numerous areas slope away from drains.

1.2 RELATED WORK

A. Section 02 82 13.21, ASBESTOS ROOFING ABATEMENT: Asbestos Removal.

B. Section 06 10 00, ROUGH CARPENTRY: Replacement Roof Deck and Parapet

Sheathing.

C. Section 07 21 13, THERMAL INSULATION: New Attic Insulation.

D. Section 07 22 00, ROOF AND DECK INSULATION: New Roof Insulation.

E. Section 07 31 13, ASPHALT SHINGLES: New Roofing System.

F. Section 07 51 00, BUILT-UP BITUMINOUS ROOFING: New Roofing System.

G. Section 07 54 23, THERMOPLASTIC POLYOLEFIN (TPO) ROOFING: New Roofing

System.

H. Section 07 60 00, FLASHING AND SHEET METAL: Sheet Metal

Counterflashing.

1.3 APPLICABLE PUBLICATIONS

A. Comply with references to extent specified in this section.

B. American National Standards Institute/Single-Ply Roofing Institute

(ANSI/SPRI):

FX-1 (R2016)............Standard Field Test Procedure for Determining the Withdrawal Resistance of Roofing Fasteners.

C. American Society for Nondestructive Testing (ASNT):

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SNT-TC-1A (2019)........Personnel Qualification and Certification for

Nondestructive Testing.

D. ASTM International (ASTM):

C208-12(2017)e2.........Cellulosic Fiber Insulating Board.

C578-19.................Rigid, Cellular Polystyrene Thermal Insulation.

C728-17a................Perlite Thermal Insulation Board.

C1177/C1177M-17.........Glass Mat Gypsum Substrate for Use as

Sheathing.

C1153-10(2015)..........Location of Wet Insulation in Roofing Systems

Using Infrared Imaging.

C1278/C1278M-17.........Standard Specification Fiber-Reinforced Gypsum

Panel.

D4263-83(2018)..........Indicating Moisture in Concrete by the Plastic

Sheet Method.

E. U.S. Department of Commerce National Institute of Standards and

Technology (NIST):

DOC PS 1-19.............Structural Plywood.

DOC PS 2-18.............Performance Standard for Wood-Based

Structural-Use Panels.

1.4 PREINSTALLATION MEETINGS

A. Conduct preinstallation meeting minimum 30 days before beginning Work of this section.

1. Required Participants:

a. Contracting Officer's Representative.

b. Designer

c. Inspection and Testing Agency.

d. Contractor.

e. Installer.

f. Manufacturer's field representative.

2. Meeting Agenda: Distribute agenda to participants minimum 3 days before meeting.

a. Removal and installation schedule.

b. Removal and installation sequence.

c. Preparatory work.

d. Protection before, during, and after installation.

e. Removal and installation.

f. Temporary roofing including daily terminations.

g. Transitions and connections to other work.

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h. Inspecting and testing.

i. Other items affecting successful completion.

3. Document and distribute meeting minutes to participants to record decisions affecting installation.

1.5 SUBMITTALS

A. Submittal Procedures: Section 01 33 23, SHOP DRAWINGS, PRODUCT DATA, AND SAMPLES.

B. Submittal Drawings:

1. Show size, configuration, and installation details.

C. Manufacturer's Literature and Data:

1. Description of each product.

2. Description of temporary roof system and components.

3. List of patching materials.

4. Recover board fastening requirements.

5. Temporary roofing installation instructions and removal instructions. Preparation instructions to receive new roofing.

D. Photographs: Document existing conditions potentially affected by roofing operations before work begins.

1.6 QUALITY ASSURANCE

A. Installer Qualifications:

1. Same installer as Section 07 22 00, ROOF AND DECK INSULATION, Section 07 31 13, ASPHALT SHINGLES, Section 07 51 00, BUILT-UP

BITUMINOUS ROOFING, & Section 07 54 23, THERMOPLASTIC POLYOLEFIN

(TPO) ROOFING.

2. Licensed to perform asbestos abatement in Project jurisdiction when removal of asbestos-containing material is required.

3. Approved by existing roofing system warrantor when work affects existing roofing system under warranty.

1.7 FIELD CONDITIONS

A. Building Occupancy: Perform work to minimize disruption to normal building operations.

B. Existing Roofing Available Information:

1. The following are available for Contractor reference:

a. Construction drawings and project manual.

2. Examine available information before beginning work of this section.

C. Weather Limitations: Proceed with reroofing preparation only during dry weather conditions as specified for new roofing installation in Section

Section 07 51 00, BUILT-UP BITUMINOUS ROOFING, Section 07 54 23, 07 01 50.19 Addenda 2 - 5

THERMOPLASTIC POLYOLEFIN (TPO) ROOFING, Section 07 56 00, FLUID-APPLIED

ROOFING.

1. Remove only as much roofing in one day as can be made watertight in same day.

D. Hazardous materials are not expected in existing roofing system.

1. Do not disturb suspected hazardous materials. When discovered, notify Contracting Officer's Representative.

2. Hazardous materials discovered during execution of the work will be removed by Government as work of a separate contract.

a. Contractor shall remove asbestos discovered during contractors evaluation of the system in accordance with Section 02 82 13.21.

E. Hazardous Materials are expected to exist in existing roofing system.

1. See Section 02 82 13.21, ASBESTOS ROOFING ABATEMENT for hazardous material removal and disposal.

a. Contractor is required to retain services of a Certified

Industrial Hygenist for asbestos testing of all materials to be disturbed by the contracted work.

2. Coordinate reroofing preparation with asbestos roofing abatement to prevent water from entering existing roofing system and building.

1.8 WARRANTY

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

Construction."

B. Existing Warranties: Perform work to maintain existing roofing warranty in effect.

1. Notify warrantor before beginning, and upon completion of reroofing.

2. Obtain warrantor's instructions for maintaining existing warranty.

PART 2 - PRODUCTS

2.1 MATERIALS

A. Patching Materials: Match existing roofing system materials.

B. Plywood Sheathing: See Section 06 10 00, ROUGH CARPENTRY.

C. Metal Flashing: See Section 07 60 00, FLASHING AND SHEET METAL.

D. Temporary Protection Materials:

1. Expanded Polystyrene (EPS) Insulation: ASTM C578-19.

2. Plywood: NIST DOC PS 1-19, Grade CD Exposure 1-18.

3. Oriented Strand Board (OSB): NIST DOC PS 2-18, Exposure 1.

E. Wire Reinforcement: Keydeck Style (2160-2-1619) Reinforcing Mesh, as manufactured by Keystone Steel and Company, 7000 S.W. Adams St., Peoria, Illinois 61641, or approved equal prior to bid.

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F. Wood Plank Deck: Nominal 1-inch x 6-inch tongue and groove plank. Do not use oil-based preservatives.

G. Temporary Roofing System Materials: Contractor's option.

H. Fasteners: Type and size required by roof membrane manufacturer to resist wind uplift.

I. Wood Screws: #12 double-coated galvanized steel screws or stainless steel self-tapping wood screws that shall be able to resist any galvanic action that may be able to develop between the nail and the pressure treatment. The use of a lesser quality screw will not be approved. Screws shall be of sufficient length to penetrate a minimum of 1-1/2-inches into the substrate.

J. Wood Nails: For securing new lumber to new lumber or new plywood/OSB to new lumber, double-coated galvanized steel or stainless-steel ring shank nails to penetrate a minimum of 1-1/2 inches into the substrate but not smaller than 8d nails. Use 16d nails where material being secured is 1-1/2-inches to 2-inches thick.

PART 3 - EXECUTION

3.1 PREPARATION

A. Examine and verify substrate suitability for product installation.

B. Protect existing construction and completed work from damage.

C. Protect landscaping from damage.

D. Maintain access to existing walkways and adjacent occupied facilities.

E. Coordinate use of rooftop fresh air intakes with Contracting Officer's

Representative to minimize effect on indoor air quality.

F. Ensure temporary protection materials are available for immediate use in case of unexpected rain.

G. Ensure roof drainage remains functional.

1. Keep drainage systems clear of debris.

2. Prevent water from entering building and existing roofing system.

H. Coordinate rooftop utilities remaining active during roofing work with

Contacting Officer's Representative.

3.2 RE-ROOFING PREPARATION – GENERAL

A. Refer to Section 01 11 00 Summary of Work.

B. Remove and discard drain strainers, clamping rings and lead flashings in accordance with specification section 01 74 19 Construction Waste

Management.

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1. Cost associated with any necessary removals at roof drains to install new roof drains and/or drain sumps shall be included in the

Base Bid.

C. The removal of abandoned roof-mounted equipment and/or curbs, as identified either on plans and/or marked on the roof, shall be included in the Base Bid.

1. Cost associated with the removal of any abandoned equipment as identified on plans and/or on the roof shall be included in the Base

Bid.

D. The Designer and Contractor shall document the actual quantities removed for materials bid on a unit price basis.

E. All existing roof mounted equipment shall be lifted or removed so that existing flashings can be totally removed.

F. Remove only as much material as can be totally replaced in the same day.

G. Demolition shall be performed by personnel familiar with the replacement of materials being used.

H. Demolition adjacent to areas to remain shall be performed in a neat manner with straight lines to facilitate tie-ins of replacement materials. Contractor shall review tie-in methods with the Designer for approval. Designer has final approval of such methods.

I. Excessive demolition, as determined by the Owner's representative, shall be replaced with equal materials at the Contractor's expense in accordance with the General Conditions of the Contract.

J. No demolition shall be performed if the chance of precipitation is 40% or more as reported by the nearest office of the National Weather

Service.

K. Notify Contacting Officer's Representative of planned operations, daily.

1. Identify location and extent of roofing removal.

2. Request authorization to proceed.

L. Prior to the installation of any new roofing, flashings, metal flashings, any other miscellaneous items, the Contractor shall clean surfaces of all dust, dirt, and other foreign materials.

M. Prior to the installation of any new roofing materials, extend all existing soil pipe vents through the roof to a minimum height of 8 inches (or as required by local plumbing codes) above the finished roof surface. Furnish a piece of PVC piping that will fit snugly into the

07 01 50.19 Addenda 2 - 8 existing soil pipe vent and shall extend into the pipe a minimum of 12 inches. Provide a second PVC pipe that fits snugly around the smaller

PVC pipe and shall provide a minimum 8" height above the finished roof surface. The smaller pipe height shall match the outer pipe. Cement the two PVC pipes together with an approved pipe solvent/glue. Insert the extension into the existing soil pipe vent.

1. Note: The placement of a PVC pipe extension directly on top of the existing soil pipe vent without the support method described above shall be removed by the Contractor and new extensions approved by the Designer shall be installed at no additional cost to the Owner.

3.3 COMPLETE ROOFING SYSTEM REMOVAL

A. Remove existing roofing system completely, exposing structural roof deck.

1. Remove cover board, roof insulation, and base sheet/underlayment.

2. Remove or cut-off roofing system fasteners.

3.4 DECK PREPARATION

A. Inspect structural roof deck after roofing system removal.

B. Lightweight Concrete Roof Decks:

1. Visually confirm concrete roof deck is dry.

2. Perform moisture test according to ASTM D4263-83(2018) each day for each separate roof area.

a. Proceed with roofing work only when moisture is not observed.

3. Abandoned Penetrations at Lightweight Insulating Concrete Fill

a. At all abandoned roof penetrations, less than 12 inches in diameter, secure a piece of 20 ga. galvanized steel to the existing concrete at spacings not to exceed 6 inches on center and located approximately one inch from the edge of the opening.

Toggle bolts shall be used to secure sheet metal to the steel center or form board. The sheet metal shall extend onto the existing concrete a minimum of 6 inches.

b. At abandoned curb locations with areas larger than 12 inches at lightweight concrete fill deck close the deck opening.

1) (Steel Centering) Cut back the existing concrete and insulation fill onto the existing steel centering so that new vented steel centering will rest on a minimum of 3 structural supports and extend a minimum of 12 inches onto the existing steel decking. Do not cut the existing steel centering.

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2) Lightweight insulating concrete fill shall be sufficiently mixed to provide a consistent, thorough mix that will screed to a smooth surface.

3) Contractor shall submit technical data to the Designer for review and approval before the start of this phase of the work.

4) Prior to the installation of any lightweight concrete fill, clean surfaces of all dust, dirt and other foreign matter.

5) Apply a leveling course of NVS concrete that shall fill flutes and have a minimum thickness of ⅛ inch over the top rib of the vented steel centering.

6) Apply lightweight concrete fill in strict accordance with manufacturer’s written instructions.

7) Allow 2-3 hours for the slurry coat and top fill of lightweight insulating concrete to properly cure. The new lightweight insulating concrete fill decking shall match the existing in slope and profile to promote current drainage.

8) Contractor shall take additional precautions to protect interior furnishings and equipment prior to the start of lightweight insulating concrete fill operations, such as providing building personnel with plastic sheet coverings for equipment and furniture. Any spillage of lightweight concrete fill into interior spaces shall be cleaned up to the satisfaction of the Owner at no additional cost to the Owner.

C. Tongue-and-Groove Wood Plank Roof Decks:

1. Visually inspect tongue-and-groove wood plank roof deck installation and fasteners.

a. Notify Contracting Officer's Representative of unsuitable conditions and inadequate fastenings potentially affecting roof system performance.

2. Secure new boards to the existing framing with 2 fasteners at each framing member. New boards shall span a minimum of 4 framing members.

3. Secure the existing roof deck with 2 fasteners per framing member where existing fastening is missing.

4. Replace roof deck as determined by Contracting Officer's

Representative.

a. Replacement Roof Deck: See Section 06 10 00, ROUGH CARPENTRY.

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3.5 BASE FLASHING REMOVAL

A. Expose base flashings to permit removal.

1. Two-Piece Counterflashings: Remove cap flashing and store for reuse.

2. Single Piece Counterflashings: Carefully bend counterflashing.

3. Metal Copings: Remove decorative cap and store for reuse.

B. Remove existing base flashings.

1. Clean substrates to receive new flashings.

C. Replace counterflashings damaged during removal.

1. Counterflashings: See Section 07 60 00 FLASHING AND SHEET METAL.

3.6 UNIT PRICE REMOVAL AND REPLACEMENT

A. Refer to specification section 01 22 13 Unit Prices and Allowances for removal and replacement of damaged and deteriorated materials uncovered during the process of roof replacement.

B. Contractor shall include allowances as indicated on the Bid Form and in

Specification Section 01 22 13 Unit Prices and Allowances in the Base

Bid. Contract will be increased at unit price rates for unit price work that exceeds allowances. Contract will be reduced for unused unit price work at the bid unit price rate. Owner reserves the right to negotiate lump sum modifications to the contract for bulk unit price work.

3.7 FIELD QUALITY CONTROL

A. Field Tests: Performed by testing laboratory specified in Section

01 45 29, TESTING LABORATORY SERVICES.

1. Fastener Pull Out Tests: ANSI/SPRI FX-1(2021).

2. Adhered Pull Tests: ANSI/SPRI IA-1(2021)

B. Existing Roofing System Warrantor Services:

1. Inspect reroofing preparation and roofing installation to verify compliance with existing warranty conditions.

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

3.8 DISPOSAL

A. Collect waste materials in containers.

B. Remove waste materials from project site, regularly, to prevent accumulation.

C. Legally dispose of waste materials.

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