A04_SOW.docx

STATEMENT OF WORK

California Trail Center Roof Replacement Table of Contents

1. GENERAL

1.1 Scope of Work

The Bureau of Land Management (BLM) is seeking services of a professional contractor to replace a portion of the California Trail Center’s existing roof with a new PVC roof.

The California Trail Interpretive Center is located off I-80 eight miles west of Elko, Nevada at the address 1 Interpretive Center Way, Hunter Exit 292, Elko, Nevada 89801

The California Trail Center’s principal building is 16,444 square feet and was constructed in 2007. CTIC is a visitor center that tells of how westward expansion shaped America’s character and identity.

The Center is open Wednesday to Sunday from 8:30am-5:00pm.

Approximately 1,245 square feet of ballasted Ethylene Propylene Diene Monomer (EPDM) roof is to be replaced with new 60-mil PVC adhered roof. The existing roof is prone to leaks and the surface of the existing roof is not sloped properly to direct drainage to one pair of the existing roof overflow drains.

Review loading limitations of deck before beginning roofing project and ensure weights fall within acceptable ranges. Existing ballast shall be removed from the entire part of the roof scheduled for replacement during construction to prevent overloading of the existing structure.

The parapet wall extends above the roof surface approximately 4 to 6 inches. The roof is roughly flat with a ¼ drop per foot pitched southwards to two sets of roof and overflow drains.

Project Access: There are no stairs going to the roof and appropriate equipment such as a truck/lift bucket or an extension ladder will be required to access the roof. There is a wide concrete path adjacent to the proposed roof replacement. A personnel ladder provides access through a hatch to the roof which can be used by personnel. Electric wires prevent any materials or tools from being carried up the ladder through the access hatch.

1.2 Work Description

Replacement of approximately 1,245 square feet of an existing ballasted EPDM commercial roof to be with a new 60-mil PVC adhered roof. New roof color shall be tan. Furnish all labor, equipment, supplies and materials, necessary to complete the work.

Store products in manufacturer’s unopened packaging until ready for installation. Protect materials from exposure to moisture and other elements.

Demolish and dispose the existing roof materials properly and in accordance with all federal and local regulations. Install new roofing system including a new PVC thermoplastic membrane, new cover board, new insulation, and new air/moisture barrier per drawings and attached specification Section 07540. Replace vent seals, flashing, metal coping, trim and all other work needed to make the roof complete. The Contractor shall replace the sheathing.

Adjust vent pipes as required to meet applicable code requirements. Extension may be required.

Replace the parapet cap.

Replace coping where the ladder is to be relocated.

Aesthetic consideration: Select a tan PVC roof product to ensure roof is aesthetically consistent as viewed from the trail on the hill adjacent to the building. Ensure external facing metal coping closely matches existing.

Contractor to verify rooftop apparatuses which include but not are not limited to: two vents through the roof, electric cabling and outlets running along the top of the rooftop, an personnel access hatch, a 24” x 25” air intake, electrical conduit penetrations, a centrifugal vent fan, and two pairs of water drain with overflow drains.

Contractor to verify fastening system will not impact existing electrical or utility system below metal decking.

The Contractor shall provide experienced roofers certified by the manufacturer to work on the roof and provide all safety equipment required by OSHA. This roof system has no safe access system, nor is there any safety rails, tie-offs or fall protection devices available. Exercise caution when walking on dew, frost, ice, or snow covered roof, since the membrane may be extremely slippery.

Demolition: Do not schedule roofing tear-off or new work when inclement weather is forecast or imminent. Do not continue to tear off or install new work when inclement weather is imminent or “tie off” work in progress. Provide water cut-offs and maintain a system to provide rapid protection of exposed structure or of uncompleted work in the event of sudden inclement weather. All temporary work that is used to protect work at end of day or from weather is to be completely removed prior to resuming permanent work.

Demolition and legal disposal of existing roofing system: materials removed from roof shall become property of the contractor who shall be responsible for their legal disposal offsite. Ballasting gravel and footpath materials shall become property of the contractor.

Existing Parapet Wall Coping: Remove existing parapet wall coping and replace with PVC membrane flashing in matching color. The coping specs 07620 are from the original project.

Protection: Arrange work to prevent transportation of demo or new work materials across newly installed roof areas and restrict high foot traffic.

New Material: All roofing system material and accessories shall be provided in new condition, according to manufactures written details and guidelines.

Installation: Contractor shall install roofing system per manufacturer’s detail, guidelines, industry standards and code requirements, and shall not inhibit proper water flow.

Calculations and Test: All roof installation and details shall be completed in accordance with the Roofing System manufacturer’s guidelines. Roofing system attachment shall be completed according to ASCE 7 calculations and associated ASTM 1952 test results.

Single Source Manufacturer: All roofing materials, flashing and vent seals shall be provided by a single source manufacturer and covered under the roofing warranty.

Color: Accessories exposed at or below the outside roof line shall match as close as possible to the existing color of the current trim/siding. The PVC membrane shall be tan. Contractor to provide a color sample of the proposed new PVC material prior to submitting order from manufacturer or supplier.

Roof System: The new roof system shall address thermal expansion and contraction, uniform wind load capacity, static pressure, air infiltration and static pressure of water infiltration.

Manufacturer's Field Service Inspection: Per attached specification Section 07540, engage a factory-authorized service representative to test and inspect roofing installation, including accessories, and submit the inspection report.

Contractor License: Contractor performing work shall hold a State of Nevada Contractor’s License and be trained and certified in the specific product installation.

Prior to the placement of membrane underlayment, clear the substrate of debris and foreign material that may be harmful to the roofing system. Gaps greater than 1⁄4" must be filled with an appropriate nonshrink material such as grout or latex.

When loading materials onto the roof, the Roofing Contractor must comply with the requirements of the project to prevent overloading and possible damage to the building structure. Contractor to not place all material on one side of the roof leading to overloading.

PVC Walkway Mat: Provide a 2’ loose-laid drainable walkway mat such as crossgrip PVC or approved similar that allows for loose-laying and drains well. The mat shall be provided from the access roof hatch to heavily trafficked areas as shown on the roof plan such as the upper roof ladder and to the centrifugal vent.

Installation best practices:

Contractor to install per manufacturer’s instructions.

Proper roof deck preparation is essential to simplify installation and prevent future conditions that may lead to roof leaks. Strip the roof down to its base and inspect for any hidden problems, such as trapped moisture or weak areas. Identify to the COR these and resolve any latent issues before commencing with installation.

Carefully sweep all roof surfaces to remove all debris and dirt. Make sure the roofing area is completely smooth. Repair holes or cracks in metal deck, greater than ¼" (6.35 mm) wide with non-shrink grout. A slipsheet shall be used underneath the membrane. Before welding, ensure area is clean and dry. Remove dirt or contamination from membrane before welding by using low-sudsing soap and water followed by a single ply membrane cleaner. Thoroughly dry all weld surfaces prior to welding. Hot air welding equipment is required to make all field seams. Welding speeds will be slower in high humidity conditions or at low temperatures. Take at least twice the usual number of seam samples to test for peel resistance, since the possibility of inferior welds is greater. Seams must be loaded in shear and not in peel. A shear load would be in the plane (horizontal) of the roof membrane. A peel load would be lifting the seam perpendicular to the roof. All roofs expand and contract during temperature changes. This can produce mechanical stress in the membrane. It is important to make welds that do not cause peel stresses to occur. The correct and incorrect methods for welding at the roof surface and side corners are described below. Correct: Weld the membrane to horizontal surface of the PVC-Coated Metal or membrane flashing, producing only horizontal stress (shear stress) on the welded seam. This also helps transfer stress to the roof structure. Incorrect: The weld is subject to vertical stress (peel stress). Peel stresses weaken and may eventually rupture the welded seam.

Repairing Scorched Membranes:

If the membrane surface is overheated, a good weld cannot be achieved. The burned or discolored membrane must be patched. To repair a burned section, cut away the damaged material at least 1" (2.54 cm) beyond the burned edges. Patches should be cut to extend at least 3" (7.62 cm) beyond all damaged edges. Allow for a minimum 1½" (3.81 cm) weld width on all sides. Center the patch over the cut area and weld to the membrane, using normal welding procedures. Cut all patches in a square or rectangular shape with round corners for a neat, finished roof appearance.

Vapor Retarder Vapor retarders prevent moisture or condensation from entering the building or passing from the building into the roof system. To provide an effective shield against water vapor, seal off all vapor retarders at roof edges and penetrations. A slipsheet shall be used under the membrane. It provides a smooth surface over which the membrane can freely expand or contract when temperature variations cause changes in the roof structure. The slipsheet is loosely laid and usually overlapped, depending on the slipsheet selected. It should be neatly cut to fit closely against roof edges and around penetrations. An approved slipsheet must be used between the PVC Membrane and any polystyrene insulation product.

Insulation Remove existing insulation and replace with new rigid insulation. Taper insulation to allow positive drainage. Maintain a minimum of 4” of rigid insulation.

Adding insulation boards to the roof deck is a key step for improving energy efficiency and creating a smooth, even surface for the PVC membrane. Exact measurements are responsibility of the contractor. All insulation to be rigid. See specifications for performance requirements.

Densdeck or approved similar Install siliconized gypsum with fiberglass board as described in specifications above rigid insulation and below roof membrane. Board to provide hail proofing to the membrane.

Installing the Membrane Unroll the PVC Membrane and position without stretching. Allow the membrane to relax at least 15 minutes when the temperature is above 60°F (16°C), or 30 minutes when the temperature is below 60°F (16°C), prior to installation. Inspect for any damage on the membrane. Remove sections of the membrane that are creased or damaged. As the CTIC roof is on a steel deck, the membrane sheets should be applied perpendicular to the ribs (flutes) of the deck.

Welding Membranes to Roof Edges If the membrane has a metal edge installed it is stripped into the field sheet with a detail strip.

Penetrations Apply one tube of Single Ply Caulk around the drain bowl. Apply the PVC Membrane to overlay drain area, cut out hole in center area 2" (5.08 cm) smaller than metal drain bowl diameter. Cut round holes one-half the size of bolt diameter at drain bolt penetrations. Make sure there are no seams or fasteners through the drain clamping ring. Carefully press membrane drain flashing over drain bowl area and work into the caulk to form seal. Cut PVC Membrane Base Flashing extending vertically 8" (20.32 cm) minimum, leaving enough membrane at the flashing base to overlap fasteners/plates and to provide for a 1½" (3.81 cm) minimum continuous weld. For vent pipe flashing prepare a square detail membrane stretch collar. Using a hand-held hot air welder, heat the area around the stretch collar hole, and stretch fit membrane over the pipe to create a 1" (2.54 cm) turn-up with the collar seated flush on the field membrane.

Air and Vapor Barrier (A&VB)

1. It is critical to keep the temperature of the Air and Vapor barrier membrane above 60°F (15.5°C), as low temperatures can negatively affect adhesion.

2. Primer must be kept above 60°F (15.5°C) prior to installation. Low VOC Adhesive/Primers are particularly susceptible to cold.

3. A&VB membrane shall be properly rolled in. Asphalt adhesive is pressure sensitive. To ensure proper contact, A&VB field sheets must be rolled with a 100- to 150 lb. roller, and vertical surfaces must be rolled with a hand roller. When installing a VapAir Seal directly over metal decks, brooming the sheet is acceptable. Follow manufacturer’s instructions on whether priming is required.

4. Seam rolling: To ensure proper adhesion, it is critical that seams are rolled in with a seam roller.

5. If the contractor elects to use a gypsum board above the roof metal decking, then it will be considered ancillary to the roof installation costs and not be compensated separately. OSB is not acceptable as a substrate material.

If roof is to be built above existing profile due to reshaping of insulation the new roof membrane should be a minimum of 1” below the top of the existing metal coping.

1.4 Bid Option Item: New Crickets

The original plans for the CTIC center recommended installing roof crickets at all roof top curbs. Beyond the additional roof cricket for installation by the access hatch in the southeastern most corner, the bid option is for removal and reinstallation of the roof crickets if a condition assessment demonstrates that they are not in good condition for installation of the new roof.

1.5 Construction Administration

Attend a Pre-Construction meeting which will be scheduled and coordinated by the COR. See project specifications for details and agenda.

1.6 Project Site cleanup

a. Project site cleanup includes the removal and proper disposal of all construction trash, debris, and residue off the BLM project site. Items such as miscellaneous construction materials are considered the property of Contractor and shall be removed from the project site.

b. During the Work, Contractor is required to furnish dumpsters or other trash receptacles and to empty such containers either as they become full or weekly, whichever is more frequent. Contractor shall not place materials of any kind into private or Government trash bins or dumpsters.

c. All damages caused to the property including walls, ceilings, doors, carpets, and pavements caused by Contractor or his/her representatives and staff shall be repaired free of charges to BLM to the satisfaction of the COR.

d. Clean the working area prior to closeout.

1.7 Codes/Standards

All work performed, equipment, and materials used under this scope of work shall be in accordance with all building codes, and industry standards of Authorities Having Jurisdictions over BLM work. Contractor to confirm Elko County requirements:

· Wind Load - 89 mph, exposure “C” (115 mph, 3 second gust)

· Snow Loads (both ground and roof) 30 PSF

· Wind Exposure C

Note the original building was designed with wind uplift pressures of:

a. Corner Zones: 34 psf.

b. Side Zones: 31 psf.

c. Interior Zones: 19 psf.

1.8 Warranties

· Service Warranty: See the specifications.

· Product Warranty: See the specifications.

1.9 SALVAGEABLE ITEMS:

The existing roof is EPDM. Coordinate with the BLM to retain 100 SF of the existing EPDM; this shall be the portion of existing EDPM that is most intact after removal. The rest of the membrane will become property of the contractor.

1.10 Project Closeout

a. Removal of Protection Items: Remove any temporary items installed for protection of the work site during construction.

b. Disposal compliance: Comply with regulations of authorities having jurisdiction and safety standards for cleaning. Do not burn waste materials. Do not bury debris or excess materials on Government property. Do not discharge volatile, harmful, or dangerous materials into drainage systems. Remove waste materials from the site and dispose of lawfully. Clean the site of rubbish, litter, and other foreign substances. Vacuum carpets, cleans walls and all surfaces, sweep paved areas broom clean, remove stains, spills, and other foreign deposits which were caused and created by the contractor’s operation. Remove waste materials from the site and dispose of lawfully. Clean the site of rubbish, litter, and other foreign substances.

c. Provide operation, maintenance, and warranty data and information to the COR.

2. CONTRACTUAL

2.1 Period of Performance

a. Work shall commence no later than 63 calendar days (9 weeks) from the issuance of the Notice to Procced (NTP).

b. Time of performance of work for all items shall not exceed 56 calendar days (8 weeks) from date of commence of work.

c. Perform work Monday through Friday, from 7:30 AM to 4:30 PM, except on legal Government holidays. Other working hours and/or arrangements may be made if agreed upon in advance by the COR. Contractor shall have no expectation that COR will approve changes to stated work schedule.

d. Delays due to matters outside of Contractor’s control may be considered by the Contracting Officer (CO), with written request by Contractor.

2.2 Measurement and Payment

a. All services, supplies, materials, and labor necessary to perform the work shall be provided under this contract.

b. The payment will be made under a lump sum item for all worked described above. All items not described above but needed to accomplish the work will be considered incidental, and no direct payment will be made. Progress payments will be allowed in accordance with the bid schedule items, not to exceed 90% of each item.

c. The remaining 10% of the contact amount will be paid after the final acceptance of the completed contract.

3. CONTRACT BID REQUIREMENTS

Bid Schedule:

1) A bid schedule shall accompany the submission of the bid.

2) The bid schedule shall contain all base bid items.

ATTACHMENTS

a. “2025 CTIC Roof Replacement” Drawings Dated August 2025

b. Original Construction Drawings for the California Trail Center dated October 2005.

c. Roof Specifications 07540-5

d. Flashing and Coping Specifications 07620 image1.png