07 01 50.19 - PREPARATION FOR RE-ROOFING and ROOFING REHABILITATION.pdf

Addendum #01 April 27, 2026 Columbus VAMC – Replace Roof Building 1A

#757-21-101

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PREPARATION FOR RE-ROOFING & ROOFING REHABILITATION

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SECTION 07 01 50.19

PREPARATION FOR RE-ROOFING & ROOFING REHABILITATION

PART 1 - GENERAL

1.1 SUMMARY

A. Section Includes:

1. Complete roof removal for new roof system installation.

2. Partial roof removal for roof system repairs and rehabilitation of existing remaining installation.

3. Selective roofing system component removal for new roof membrane installation.

4. Existing roofing membrane preparation for rehabilitation of existing roofing membrane system.

B. Existing Roofing Systems:

1. PVC - System components include:

a. Roofing membrane.

b. Cover board.

c. Roof insulation.

2. TPO – System components include:

a. Roofing membrane.

b. Roof insulation.

1.2 RELATED WORK

A. SECTION 07 01 50.74 REHABILITATION OF EXISTING MEMBRANE ROOFING: Roof rehabilitation.

B. Section 07 52 16.11, COLD-ADHESIVE STYRENE-BUTADIENE-STYRENE MODIFIED

BITUMINOUS MEMBRANE, ROOFING: New Roofing System.

C. 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. ASTM International (ASTM):

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

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

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

Sheet Method.

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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. Architect/Engineer.

c. Contractor.

d. Installer.

e. Manufacturer's field representative.

f. Other installers responsible for adjacent and intersecting work, including mechanical and electrical equipment installers.

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.

h. 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 or roof preparation service.

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 01 50.74 - REHABILITATION OF EXISTING

MEMBRANE ROOFING, Section 07 54 19 - POLYVINYL-CHLORIDE (PVC)

ROOFING, Section 07 54 23 - THERMOPLASTIC POLYOLEFIN (TPO) ROOFING, Section 07 71 00 - ROOFING SPECIALTIES.

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

B. Manufacturer Construction Observation: Submit letter from the manufacturer indicating who the technical inspector will be, experience qualifications, assurance of non-sales related functions or Registered

Roof Observer certification along with copies of prior reports.

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

Representatives. The approved inspector must be certified as a

Registered Roof Observer by the Roof Consultants Institute.

a. Preparatory inspection.

b. Initial inspection.

c. Daily inspections.

1.7 FIELD CONDITIONS

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

1. Provide notice minimum 72 hours before beginning activities affecting normal building operations.

B. Existing Roofing Available Information:

1. The following are available for Contractor reference:

a. Roof moisture survey.

b. Test cores analysis.

c. 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

07 01 50.74 - REHABILITATION OF EXISTING MEMBRANE ROOFING, Section

Section 07 54 19 - POLYVINYL-CHLORIDE (PVC) ROOFING, Section 07 54 23

- THERMOPLASTIC POLYOLEFIN (TPO) ROOFING.

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

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1.8 WARRANTY

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

Construction."

PART 2 - PRODUCTS

2.1 MATERIALS

A. Patching Materials: Match existing roofing system materials or as required by roof rehabilitation system manufacturer.

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

C. 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.

PART 3 - EXECUTION

3.1 PREPARATION

A. Examine and verify substrate suitability for product installation.

B. Protect existing roofing system indicated to remain.

1. Cover roof membrane with temporary protection materials without impeding drainage.

2. Limit traffic and material storage to protected areas.

3. Maintain temporary protection until localized repair/replacement roofing is completed.

C. Protect existing construction and completed work from damage.

D. Protect landscaping from damage.

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

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

Representative to minimize effect on indoor air quality.

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

H. Ensure roof drainage remains functional.

1. Keep drainage systems clear of debris.

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

I. Coordinate rooftop utilities remaining active during roofing work with

Contacting Officer's Representative.

3.2 RE-ROOFING PREPARATION - GENERAL

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

1. Identify location and extent of roofing removal.

2. Request authorization to proceed.

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3.3 OVERBURDEN REMOVAL

A. Remove existing temporary storage units, loose walkpads and integrated walkway materials.

1. Store temporary storage units for reinstallation to existing locations.

2. Dispose of loose walkpad material unless Owner desires to keep onsite.

3.4 COMPLETE ROOFING SYSTEM REMOVAL

A. Remove existing roofing system completely as noted on drawings, exposing structural roof deck and properly dispose.

1. Remove single ply membrane, cover board, roof insulation, vapor retarder.

2. Remove or cut-off roofing system fasteners where applicable.

3.5 PARTIAL ROOFING SYSTEM REMOVAL

A. Remove existing designated areas of roofing and insulation completely as noted on drawings for patching of existing membrane, exposing structural roof deck at locations and to extent indicated on drawings.

1. Remove single ply membrane, cover board, roof insulation, vapor retarder.

2. Remove or cut-off roofing system fasteners where applicable.

3. Reinstall new vapor retarder, insulation coverboard and membrane in accordance with appropriate specification section to get membrane back into a 100% watertight condition each day of removal operations.

3.6 SELECTIVE ROOFING SYSTEM COMPONENT REMOVAL

A. Remove existing roofing membrane sheet metal flashings in locations and to extent indicated on drawings.

B. Visually inspect underlying substrate conditions.

1. Coordinate with Contracting Officer's Representative to observe inspections or existing deteriorated substrate conditions not suitable for work as specified.

2. Roofing membrane & flashing system to remain watertight at all times during operations if materials remain removed at the end of each work day.

3.7 SINGLE PLY MEMBRANE PREPARATION

A. Water Reclamation: Provide cleaning of membrane roofing that provides

100 percent reclamation of cleaning water and complies with applicable provisions of the US EPA National Pollutant Discharge Elimination

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System (NPDES) program and requirements of local authorities having jurisdiction.

1. Utilize cleaning protocols, systems and cleaning agents as recommended by roof rehabilitation system manufacturer to ensure warranty issuance.

B. Pretreat membrane and flashings when recommended by roof rehabilitation system manufacturer based upon site assessment of membrane condition.

Apply pressure wash cleaning solutions onto membrane and flashing surfaces.

C. Pressure wash roof membrane field and base flashing substrate with minimum 2000 psi self-contained rotating head apparatus with integrated vacuum water recovery and filtration system to remove contaminants such as dirt, debris, oil, and grease that can affect adhesion of coating.

In order to comply with applicable provisions of the US EPA National

Pollutant Discharge Elimination System (NPDES) program and requirements of local authorities having jurisdiction, all pressure wash water and cleaning agents shall be captured and removed from the roof surface and filtered before disposal into sanitary sewer system.

D. Verify that existing substrate is dry and clean before proceeding with application of membrane rehabilitation system. Spot check substrates with an electrical capacitance moisture-detection meter.

3.8 DECK PREPARATION

A. Inspect structural roof deck after roofing system removal.

B. 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 or according to test method required for acceptance for warrantying roof rehabilitation system manufacturer.

a. Proceed with roofing work only when moisture is not observed or as directed by warrantying roof rehabilitation system manufacturer.

C. Steel Roof Decks:

1. Visually inspect structural roof deck installation and fasteners.

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

2. Secure roof deck with additional fastenings if needed as determined by Contracting Officer's Representative.

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3.9 BASE FLASHING REMOVAL

A. Expose base flashings to permit removal where required.

1. Two-Piece Counterflashings: Remove counterflashing from receiver.

2. Single Piece Counterflashings: Remove counterflashing.

3. Metal Copings: Remove sheet metal copings in roof replacement areas only. Sheet metal coping in roof areas to be restored/rehabilitated to remain unless otherwise noted on drawings.

B. Remove existing base flashings where part of localized wet insulation and associated membrane replacement in preparation for rehabilitation work.

1. Clean substrates to receive new flashings.

C. Replace sheet metal flashings.

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

3.10 FIELD QUALITY CONTROL

A. Roofing System Quality Control Services:

1. New roof system and rehabilitation roof system manufacturer representative inspect reroofing preparation and roofing installation daily to verify compliance with replacement and rehabilitation warranty requirements.

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

3.11 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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