Addendum _ 1 RFP _483_25 Construction Service.pdf

RFP #483-25 CONSTRUCTION SERVICES –

ROOF REPLACEMENT – LAW ENFORCEMENT CENTER

ADDENDUM #1

RFP Closing Date: August 28, at 10:30 a.m. - Revised

RFP Issue Date: July 14, 2025

RFP Addendum Issue Date: August 15, 2025

By: Melissa Hawk, Purchasing Manager

The following are amendments to the RFP #483-25 Construction Services – Roof

Replacement – Law Enforcement Center:

1. Discussions held at the mandatory pre-proposal conference held on August 6, 2025 lead to the

County staff determining that replacing the roof with the same Modified Bitumen system as currently applied would not be in the best interest of the County.

The County Government Center (located next to the Law Enforcement Center) is covered with

John Manville 50 mil PVC system. The County has not experienced any leaks or other issues since installation during 2011. Although this system is a great fit for the Government Center, it has been determined that a Thermoplastic Polyolefin Membrane will be a better option for the Law Enforcement Center, which carries a longer warranty period.

The County has chosen Johns Manville Product # JM TPO – 60 mil, white in color for the roof surface. The County has chosen Johns Manville Product # JM ProtectoR HD ½” High-Density

Polyisco Cover Board to be laid on top of the current roofing system. The County has chosen

JM TPO Walkpad A PT, grey in color. To be laid around the perimeter of each roof surface and around each HVAC unit. The County has chosen Johns Manville JM One-Part Flashing

Kit – Single Ply to be used where appropriate, such as sealing boots as located on the roof during the pre-proposal meeting.

The County will accept approved equal substitutions as per the directions in the RFP beginning on page 59. The required form to be completed and emailed to my attention begins on page

135 of the RFP.

Please remember that the proposer must carry a general contractor’s license as well as the proper insurance and remit the company’s E-verify number on the form enclosed in the RFP.

Please remember that the Law Enforcement Center is within the City Limits of Dawsonville.

The awarded Contractor will be required to obtain a business license from them and obtain the proper permit, including required inspections.

The County has modified the specifications as found within this Amendment.

The manufacturer’s warranty period has been amended to no less than a 20-year no dollar limit for the JM TPO – 60 mil product, the JM TPO Walkpad and ProtectoR HD cover board.

2. The County is extending the questions due date until August 20, 2025, by 1:00 p.m. The new answers release date will be August 22, 2025, by 1:00 p.m. The RFP opening date has been revised to August 28, 2025, at 10:30 a.m.

3. The Contractor will recover the entire roofing system of the Law Enforcement Center (three levels of roof) with the approved materials listed above.

The Contractor will remove the existing covered porch from the roof. A separate alternate line item will be submitted to replace this structure.

The Contractor will seal all penetrations of the TPO system with a liquid flashing system as listed above.

The Contractor shall:

1. Preparation of the Existing Roof:

Remove debris: Sweep the existing roof surface to remove dirt, gravel, and any loose debris.

Inspect and repair: Identify and repair any damaged areas of the existing membrane, including blisters, cracks, or punctures.

Clean the surface: Prior to applying the urethane adhesive, hydro-vac the roof to remove all dirt and fines.

Core the membrane: If applicable, core the existing membrane to check for moisture and assess its condition according to Johns Manville.

2. Installation of Separation Layer:

Insulation board: Install a layer of insulation board over the existing roof to provide thermal performance and a smooth surface.

3. TPO Membrane Installation:

Secure the membrane: Install the JM TPO membrane according to the manufacturer's instructions, either mechanically fastening or fully adhering it to the substrate.

Hot air weld seams: Ensure proper heat welding of the TPO membrane seams to create a watertight seal.

Flashings and details: Carefully flash around penetrations, edges, and other details with compatible TPO flashing materials.

4. Final Inspection:

Check seams and flashings: Thoroughly inspect all seams and flashings for proper adhesion and watertightness.

Clean the roof: Remove any debris or construction materials from the newly installed roof.

Ensure proper slope: Ensure the roof has adequate slope to prevent ponding water according to Johns Manville.

Add Alternate Work: Construct a covered 12’ x 12’ deck consisting of the proper treated wood for our door use, a 25-year shingle roofing system.

Foundation and Framing:

• Posts: Install support posts at the deck's perimeter, ensuring they are plumb and square.

• Ledger Board: Attach a ledger board to the house's framing to support the roof.

• Rafters: Frame out the roof structure by attaching rafters to the ledger board and support posts.

• Beams: Secure beams to the posts, ensuring they are level and properly supported.

• Rim Joists: Install rim joists around the perimeter of the deck, connecting them to the beams.

• Inner Joists: Install inner joists between the rim joists, spaced according to the decking material and local codes.

Roofing:

• OSB Sheathing: Cover the rafters with oriented strand board (OSB).

• Roofing Material: Install roofing material (roofing underlayment and shingles).

• Fascia: Install fascia boards along the edge of the roof.

• Flashing: Install flashing to prevent water damage where the roof meets the LEC.

Installing Decking:

• Install starter/stop clips:

• Attach clips to the rim joists, following the manufacturer's instructions for spacing and placement.

Install decking boards:

• Slide the decking boards onto the clips, ensuring proper spacing and alignment.

Secure boards:

• Fasten the decking boards to the joists using screws or hidden fasteners, following the manufacturer's recommendations for spacing and screw type.

4. All dates, other specifications, terms and conditions remain the same as posted in the RFP document.

The following are questions and answers to the RFP #483-25 Construction Services – Roof

Replacement – Law Enforcement Center:

QUESTION: Can you make NCIC criminal background checks a requirement for all personnel working on this project?

ANSWER: The Sheriff’s Office staff will reserve the right to require a criminal background check and/or drug testing on a case-by-case basis. This is due to the fact that the contractor staff will not be working inside the building nor around the inmates.

QUESTION: Can you require that relevant contractor experience must be specific to projects with a security element? Police stations, prisons, jails, etc. This does not include fire stations, post offices or general government buildings etc.

ANSWER: The RFP calls for the contractor’s experience to be a like project, which would include experience in a secured facility setting, of five years. It further requires that the work must have been within the last ten years.

QUESTION: Will you accept Johns Manville as an approved manufacturer based on the packet / data previously submitted?

ANSWER: Yes, please see the first amendment to this RFP.

QUESTION: Do y’all want all coping replaced and for the TPO, do you want it mechanically fasted or adhered?

ANSWER: Please see the first amendment for this RFP.

Company Name Signature of Authorized Representative

Title Date

THIS DOCUMENT MUST BE COMPLETED AND SUBMITTED AS PART OF YOUR PROPOSAL

SECTION 075423

THERMOPLASTIC POLYOLEFIN (TPO) MEMBRANE ROOFING

PART 1 - GENERAL

1.1 SECTION INCLUDES

A. Mechanically fastened TPO membrane roofing system

B. Cover board.

1.2 RELATED SECTIONS

A. Division 05 Section "Steel Decking" for steel roof deck.

B. Division 06 Section "Miscellaneous Rough Carpentry" for wood nailers, curbs, and blocking.

C. Division 07 Section "Sheet Metal Flashing and Trim" for flashings and counter flashings.

D. Division 22 Section "Storm Drainage Piping Specialties" for roof drains

1.3 REFERENCES

A. Roofing Terminology: Refer to the following publications for definitions of roofing work related terms used in this Section:

1. ASTM D 1079 "Standard Terminology Relating to Roofing and Waterproofing."

2. Glossary of NRCA's "The NRCA Roofing and Waterproofing Manual."

3. Roof Consultants Institute "Glossary of Roofing Terms."

4. Single Ply Roofing Industry (SPRI)

5. International Building Code (IBC)

6. American Society of Civil Engineers (ASCE-7) Minimum Design Loads for Buildings & Other

Structures

7. Sheet Metal Terminology and Techniques: SMACNA "Architectural Sheet Metal Manual."

1.4 DESIGN CRITERIA

A. General: Installed roofing membrane systems shall remain watertight; and resist specified wind uplift pressures, thermally induced movement, and exposure to weather without failure.

B. Material Compatibility: Roofing materials shall be compatible with one another under conditions of service and application required, as demonstrated by roofing system manufacturer based on testing and field experience.

C. Installer shall comply with current code requirements based on authority having jurisdiction.

D. Wind Uplift Performance: Roofing system shall meet the intent of systems that have been successfully tested by a qualified testing and inspecting agency to resist wind uplift pressure calculated in accordance with ASCE 7.

E. Fire-Test-Response Characteristics: Provide roofing materials with the fire-test-response characteristics indicated as determined by testing identical products per UL 790 or another testing and inspecting agency acceptable to authorities having jurisdiction. Materials shall be identified with appropriate markings of applicable testing and inspecting agency.

1.5 SUBMITTALS

A. Product Data: Manufacturer's data sheets for each product to be provided.

B. Detail Drawings: Provide roofing system plans, elevations, sections, details, and details of attachment to other Work, including:

1. Base flashings and membrane terminations.

2. Tapered insulation, including slopes.

3. Crickets, saddles, and tapered edge strips, including slopes.

4. Insulation fastening patterns.

C. Verification Samples: Provide for each product specified.

D. Installer Certificates: confirmation that installer is approved, authorized, or licensed by manufacture to install roofing system.

E. Maintenance Data: Refer to Johns Manville's latest published documents on www.JM.com.

F. Guarantees: Provide manufacturer's current guarantee specimen.

G. Roofing sub-contractor shall provide a copy of the final System Assembly Letter issued by Johns Manville Roofing Systems indicating that the products and system to be installed shall be eligible to receive the specified manufacturer's guarantee when installed by a certified JM contractor in accordance with our application requirements, inspected and approved by a JM Technical Representative.

H. Prior to roofing system installation, roofing sub-contractor shall provide a copy of the Guarantee Application Confirmation document issued by Johns Manville Roofing Systems indicating that the project has been reviewed for eligibility to receive the specified guarantee and registered.

1.6 QUALITY ASSURANCE

A. Installer Qualifications: Qualified firm that is approved, authorized, or licensed by roofing system manufacturer to install manufacturer's product who is eligible to receive the specified manufacturer's guarantee.

B. Manufacturer Qualifications: Qualified domestic U.S. owned and based manufacturer that has UL listing or accredited testing agency listing for roofing system identical to that used for this project.

C. Testing Agency Qualifications: Independent testing agency with the experience and capability to conduct the testing indicated, as documented in accordance with ASTM E329.

D. Test Reports:

1. Roof drain and leader test or submit plumber's verification, if required

2. Core cut, if requested.

3. Roof deck fastener pullout test, if required

4. Bonded pull test, if required.

E. Moisture Survey, if required

1. Submit prior to installation, results of a non-destructive moisture test of roof system completed by approved third party. Utilize one of the approved methods:

a. Infrared Thermography

b. Nuclear Backscatter

F. Source Limitations: Obtain all components from the single source roofing system manufacturer guaranteeing the roofing system. All products used in the system shall be labeled by the single source roofing system manufacturer issuing the guarantee.

G. Fire-Test-Response Characteristics: Roofing materials shall comply with the fire-test-response characteristics indicated as determined by testing identical products per test method below by UL or another testing and inspecting agency acceptable to authorities having jurisdiction. Materials shall be identified with appropriate markings of applicable testing and inspecting agency.

1.7 DELIVERY, STORAGE, AND HANDLING

A. Deliver roofing materials in original containers with seals unbroken and labeled with manufacturer's name, product brand name and type, date of manufacture, and directions for storage.

B. Store liquid materials in their original undamaged containers in a clean, dry, protected location and within the temperature range required by roofing system manufacturer.

C. Protect roof insulation materials from physical damage and from deterioration by sunlight, moisture, soiling, and other sources. Comply with insulation manufacturer's written instructions for handling, storing, and protecting during installation.

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

1.8 PROJECT CONDITIONS

A. Weather Limitations: Proceed with installation only when current and forecasted weather conditions permit roofing system to be installed in accordance with manufacturer's written instructions and guarantee requirements.

1.9 GUARANTEES

A. Provide manufacturer's system guarantee equal to Johns Manville's Peak Advantage No Dollar Limit Roofing System Guarantee.

1. Single-source special guarantee includes roofing membrane, base flashings, roofing membrane accessories, fasteners, adhesives, cover board, walkway products, and other approved single-source components of roofing system marketed by the manufacturer.

2. Guarantee Period: 20 years from date of Substantial Completion.

3. Contractor is required to list Larimer Shannon Group as the Specifier/Consultant of record in the appropriate fields ("Specifier Account") when applying for the manufacturer's warranty.

B. Installer's Guarantee: Submit roofing Installer's guarantee, including all components of roofing system for the following guarantee period:

1. Guarantee Period: Two years from date of Substantial Completion.

C. Existing Guarantees: Guarantees on existing building elements should not be affected by scope of work.

1. Installer is responsible for coordinating with building owner's representative to verify compliance.

PART 2 - PRODUCTS

2.1 THERMOPLASTIC POLYOLEFIN ROOFING MEMBRANE- TPO

A. Fabric-Reinforced Thermoplastic Polyolefin Sheet: ASTM D 6878, uniform, flexible sheet formed from a thermoplastic polyolefin, internally fabric or scrim reinforced. Basis of design: JM TPO

1. Membrane Thickness: 60 mils

2. Exposed Face Color: White

2.2 AUXILIARY ROOFING MATERIALS

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

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

B. Sheet Flashing: Manufacturer's internally reinforced or scrim reinforced. Basis of design: JM TPO 60 mil

C. Liquid Applied Flashing: Manufacturer's single ply liquid and fabric reinforced flashing system created with a fleece polyester scrim and a two-component polyurethane-based liquid applied flashing material, consisting of a liquid resin and a curing agent. Basis of design: JM SP Liquid Flashing Resin, JM SP Liquid Scrim

D. Liquid Applied Flashing Primer: Manufacturer's single ply liquid flashing primer. Basis of design: JM Liquid Applied Flashing Primers

E. Flashing Adhesive: Manufacturer's standard solvent-based bonding adhesive for base flashings. Basis of design: JM Membrane Bonding Adhesive (TPO & EPDM)

1. Serviceable Installation Ambient Air Temperature: 25°F and rising

F. Slip Sheet: Manufacturer's recommended slip sheet, of type required for application.

G. Metal Termination Bars: Manufacturer's standard predrilled stainless-steel or aluminum bars, with anchors. Basis of design: JM Termination Systems

H. Membrane Battens: Manufacturer's standard polymer or aluminum-zinc-alloy-coated steel sheet, pre-punched. Basis of design: JM Membrane Battens

I. Fasteners: Factory-coated steel fasteners and metal plates meeting corrosion-resistance provisions in FMG 4470, designed for fastening membrane to substrate, and acceptable to membrane roofing system manufacturer. Basis of design: JM High Load Fasteners (#15)

J. Miscellaneous Accessories: Provide all accessories to meet the roofing manufacturer's guarantee requirements.

2.3 WALKWAYS AND SAFETY STRIPS

A. Flexible Walkways: Factory-formed, nonporous, heavy-duty, slip-resisting, surface-textured walkway pads sourced from membrane roofing system manufacturer. Basis of design: JM TPO Walkpad

B. Safety Strips, if required: Manufacturer's minimum 65 mils total thickness, comprise of 30 mil yellow non-reinforced TPO membrane laminated to 35 mil white cured seaming tape. Basis of design: JM Single Ply Safety Strip

1. Exposed Face Color: Yellow

2.4 COVER BOARD

A. High-Density Polyisocyanurate: ASTM C 1289, Type II, Class 4, Grade 1, High-density Polyisocyanurate technology bonded in-line to inorganic coated glass facers with greater than 80 lbs. of compressive strength. Basis of design: JM ProtectoR® HD

1. Thickness: ½ inch (12.7 mm)

2. R-value: 2.5

PART 3 - EXECUTION

3.1 EXAMINATION

A. General:

1. Verify that roof openings and penetrations are in place and set and braced and that roof drains are securely clamped in place.

2. Verify that wood blocking, curbs, and nailers are securely anchored to roof deck at penetrations and terminations and that nailers match thicknesses of insulation.

B. Steel Decks:

1. Verify that surface plane flatness and fastening of steel roof deck complies with requirements in Division 05 Section "Steel Decking."

2. Verify that decking is visibly dry and free of moisture.

3. Verify that the decking is smooth and free of large cracks, holes or sharp changes in elevation of the surface.

4. When applicable perform pull test with the specific fastener being used on the project to confirm the fastener resistance meets the requirements for that particular system.

C. Ensure general rigidity and proper slope for drainage.

D. Verify that deck is securely fastened with no projecting fasteners and with no adjacent units more than 1/16 inch (1.6 mm) out of plane relative to adjoining deck.

E. Unacceptable panels should be brought to the attention of the General Contractor and Project Owner's Representative and shall be corrected prior to installation of roofing system.

3.2 RE-COVER PREPARATION

A. Prepare existing roof according to roofing system manufacturer's written instructions, applicable recommendations of the roofing manufacturer, and requirements in this Section.

B. Tear out all base flashings, counterflashings, pitch pans, pipe flashings, vents, sumps and like components necessary for application of new membrane.

C. Disable or remove existing roof membrane per architectural preferences and by manufacturer's written instruction.

D. Remove and replace wet, deteriorated, or damaged roof insulation and decking as identified in moisture survey.

E. Remove abandoned equipment curbs, skylights, smoke hatches, and penetrations. Install decking to match existing as directed by Owner's Representative.

F. Raise, (disconnect by licensed craftsmen, if necessary) all HVAC units and other equipment supported by curbs to conform with the following:

1. Modify curbs as required to provide a minimum 8-inch base flashing height measured from the surface of the new membrane to the top of the flashing membrane.

2. Secure top of flashing and install new metal counterflashing prior to re-installation of unit.

3. Perimeter nailers shall be elevated to match the elevation of new roof insulation.

G. Immediately remove all debris from roof surface. The demolished roof system may not be stored on the roof surface.

3.3 COVER BOARD INSTALLATION

A. Coordinate installing membrane roofing system components so cover board is not exposed to precipitation or left exposed at the end of the workday.

B. Comply with membrane roofing system manufacturer's written instructions for installing roof cover board.

C. Install cover board with long joints in a continuous straight line. Joints should be staggered between rows, abutting edges and ends per manufacturer's written instructions. Fill gaps exceeding 1/4 inch (6 mm) with cover board.

1. Cut and fit cover board within 1/4 inch (6 mm) of nailers, projections, and penetrations.

D. Trim surface of cover board where necessary at roof drains so completed surface is flush and does not restrict flow of water.

1. If required, install tapered edge strips at perimeter edges of roof that do not terminate at vertical surfaces.

E. Preliminarily Fastened Cover Board for Mechanically Fastened Systems: Install cover board with fasteners at rate required by roofing system manufacturer or applicable authority, whichever is more stringent.

3.4 ROOFING MEMBRANE INSTALLATION, GENERAL

A. Install roofing membrane in accordance with roofing system manufacturer's written instructions, applicable recommendations of the roofing manufacturer and requirements in this Section.

B. Cooperate with testing and inspecting agencies engaged or required to perform services for installing roofing system.

C. Coordinate installing roofing system so insulation and other components of the roofing membrane system not permanently exposed are not subjected to precipitation or left uncovered at the end of the workday or when rain is imminent.

1. Provide tie-offs at end of each day's work to cover exposed roofing membrane sheets and insulation.

2. Complete terminations and base flashings and provide temporary seals to prevent water from entering completed sections of roofing system.

3. Remove and discard temporary seals before beginning work on adjoining roofing.

3.5 MECHANICALLY FASTENED ROOFING MEMBRANE INSTALLATION

A. Install roofing membrane over area to receive roofing in accordance with roofing system manufacturer's written instructions.

1. Unroll roofing membrane and allow to relax before installing.

2. Install sheet in accordance with roofing system manufacturer's written instructions.

B. Accurately align roofing membranes and maintain uniform side and end laps of minimum dimensions required by manufacturer. Stagger end laps.

C. Mechanically fasten roofing membrane securely at terminations, penetrations, and perimeter of roofing.

D. Always install membrane laps perpendicular to the steel deck flutes. "Picture Frame" installation method is not permitted.

E. Apply roofing membrane with side laps shingled with slope of roof deck where possible.

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

1. Test lap edges with probe to verify seam weld continuity. Apply cut edge sealant to seal cut edges of roofing membrane.

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

a. Remove and repair any unsatisfactory sections before proceeding with work.

3. Repair tears, voids, and lapped seams in roofing membrane that do not meet requirements.

G. Spread sealant or mastic bead over deck drain flange at deck drains and securely seal roofing membrane in place with clamping ring.

H. In-Splice Attachment: Secure one edge of roofing membrane using fastening plates or metal battens centered within membrane splice and mechanically fasten roofing membrane to roof deck. Field-splice seam.

3.6 BASE FLASHING INSTALLATION

A. Install sheet flashings and preformed flashing accessories and adhere to substrates in accordance with membrane roofing system manufacturer's written instructions.

B. Apply solvent-based bonding adhesive at required rate and allow to partially dry. Do not apply bonding adhesive to seam area of flashing.

C. Apply single ply liquid applied flashing system per manufacturer's written instructions.

D. Flash penetrations and field-formed inside and outside corners with cured or uncured sheet flashing.

E. Clean seam areas and overlap and firmly roll sheet flashings into the adhesive. Weld side and end laps to ensure a watertight seam installation.

F. Terminate and seal top of sheet flashings and mechanically anchor to substrate through termination bars.

3.7 SLIP SHEET INSTALLATION

A. If required, install polyester slip sheet as a loosely laid single layer above single ply membrane per manufacturer's written instructions.

3.8 WALKWAY INSTALLATION

A. Flexible Walkways: Install walkway products in locations indicated. Heat weld and adhere walkway products to substrate with compatible adhesive according to roofing system manufacturer's written instructions.

3.9 FIELD QUALITY CONTROL

A. Owner or designated representative will provide on-site observation and inspection during installation.

B. Owner will engage a qualified testing agency to perform tests and inspections.

C. Final Roof Inspection: Arrange for roofing system manufacturer's technical representative to inspect roofing installation on completion and submit report to owner or designated representative.

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

E. Additional testing and inspecting, at Contractor's expense, will be performed to determine compliance of replaced or additional work with specified requirements.

3.10 PROTECTION AND CLEANING

A. Protect roofing system from damage and wear during remainder of construction period.

B. Correct deficiencies in or remove roofing system that does not comply with requirements, repair substrates, and repair or reinstall roofing system to a condition free of damage and deterioration at time of Substantial Completion and according to warranty requirements.

C. Clean overspray and spillage from adjacent construction using cleaning agents and procedures recommended by manufacturer of affected construction.

END OF SECTION 075423

RFP #483-25 CONSTRUCTION SERVICES - ROOF REPLACEMENT - LAW ENFORCEMENT CENTER

PROPOSER’S PRICE PROPOSAL FORM (SHEET A)

COMPANY NAME: _________________________________________________________

ITEM DESCRIPTION ESTIMATED

QUANTITY

UOM UNIT COST EXTENDED

COST

LEC Roof Section 1 – Turn-Key 1 Lump Sum

LEC Roof Section 2 – Turn Key 1 Lump Sum

LEC Roof Section 3 – Turn-Key 1 Lump Sum

LEC Roof Section 4 – Turn Key 1 Lump Sum

Add Alternate:

ITEM DESCRIPTION ESTIMATED

QUANTITY

UOM UNIT COST EXTENDED

COST

Install a covered deck on main roof

1 Lump Sum

• All costs incurred by the Proposer must be included in the Price of Project for the total scope of work as listed in this RFP.

• Proposer to provide all materials, labor and equipment needed to complete the Scope of Work.

Authorized Signature Title

Print Name Date

THIS PAGE MUST BE COMPLETED AND SUBMITTED AS A PART OF YOUR PROPOSAL