140P9721Q0021 Specifications -Shingle Six Toklat Road Camp A-Frame Roofs.pdf

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Re-Shingle Six A-Frame Buildings at Toklat Road Camp in Denali National Park

General specifications and requirements for: 1) Removing and disposing of existing cedar shake roofing; 2) Installing foam insulation on existing roof decking; 3) Installing new decking and underlayment membrane on top of the installed foam; and 4) Installing a ventilation layer and shingles or shakes at Toklat Road Camp at mile 53.5 of the Park Road of Denali National Park & Preserve

One face of one of six A-Frames (typ)

General Specifications:

The object of these specifications is to specify the material and workmanship necessary to complete a re-roofing project. All work shall be implemented in strict accordance with manufacturer's instructions and shall be performed in a manner satisfactory to the National Park Service (NPS).

Vendor job site access at mile 53.5 of the Denali Park Road (Toklat Road Camp) will not be available until Saturday, May 1, 2021 and Vendor’s services are to be completed no later than Wednesday, June 30, 2021. Road access is subject to hazardous geological movements beyond the control of NPS and the job site may not be accessible for some or all of the contract period. In such eventualities, contracted work will be cancelled, delayed, or suspended in progress per NPS.

QUALITY OF MATERIALS:

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The materials mentioned in the following specifications are standards of quality. The standard "or equal" clause shall apply. No substitution will be considered unless a written request for approval has been received by NPS. Each such request shall include the name of the specified material for which a substitute is being requested;

the name of the proposed substitute material; and a complete description of the proposed substitute including performance and test data and any other information necessary for an evaluation. The burden of proof of the merit of the proposed substitute is upon the proposer. The decision of NPS regarding approval or disapproval of the proposed substitution shall be final.

All material shall be brought to the job site in the original sealed and labeled containers or packaging and shall be subject to inspection by NPS. Colors and finishes, where not specified, shall be selected by the National Park Service.

APPLICATION OF MATERIALS:

The Contractor shall install materials in accordance with these specifications and the manufacturer's recommendations. If materials are not installed as specified, it shall be the contractor’s responsibility to remove all such incorrectly applied materials and to re-apply materials, as specified, to NPS approval.

All materials, supplies, and fasteners shall be applied in strict accordance with the manufacturer's specifications and container and/or packaging labelling. Materials shall not be applied to wet or damp surfaces and shall not be applied when exposed to rain, snow, fog, or mist, when the relative humidity exceeds 85%, and/or when the immediate work area air temperature is below or will drop below recommended levels.

Existing structures shall be protected from intrusions of weather (rain, snow, wind, etc.) during the course of the work and exterior and interior components of the buildings shall be, at all times, protected from damage by the contractor. All such damage due to contractor negligence shall be repaired by the Contractor or at the Contractor’s expense.

All work is to be completed no later than Wednesday, June 30, 2021.

Specifications:

Requirements:

All work to be completed in accordance with applicable federal, state, and local regulations and in compliance with environmental safety and health regulations.

All project trash including roofing tear-off debris (such as old underlayment, fasteners, and shakes or shingles) will be disposed of by the contractor. Debris shall be, when possible, prevented from coming in contact with native ground covers and vegetation by tarps or sheeting. All trash and construction debris, 140P9721Q0021 Specifications and Scope of Work 3 of 6 including metal fasteners, shall be carefully and fully removed from the construction sites and all areas used by the contractor. All construction debris must be disposed of in accordance with applicable federal, state and local regulations. Contractor shall provide own construction trash disposal.

Household trash only may be disposed of through the NPS household trash compactor at Toklat Road Camp. No construction waste is to be put into any NPS waste receptacles.

All work shall be implemented in accordance with industry standards and any applicable federal, state and local regulations. OSHA standards shall be adhered to.

Work shall be warrantied in accordance with FAR 52.246-21, Warranty of Construction.

Cross-section illustrative purposes only. The details of installation will differ.

MATERIAL SPECIFICATIONS

a. EXISTING ROOF DECKING: It is anticipated that existing sheet roof decking (with no known problems) will be re-used under this contract, but Contractor will be expected to replace any damaged, rotten, or missing roof decking with exterior grade plywood of compatible dimensions before application of foam insulation. Contractor will allow and arrange for NPS to inspect all roof decking prior to installation of the successive layers listed below.

b. FOAM INSULATION: Two 1” layers of loose laid mold and insect-resistant closed-cell expanded polystyrene (EPS) foam insulation (for a total depth of 2”) shall be installed by the contractor. Combined R-value shall meet or exceed 8.0. Joints in these two layers will be staggered and taped to prevent air infiltration. Contractor shall supply NPS with installation and product information for pre-purchase approval.

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c. ROOF DECKING: Exterior plywood roof decking (not oriented strand board [OSB]) to be installed by the contractor as a continuous layer per manufacturer’s instructions on top of the foam insulation. Decking of sufficient thickness for shingle or shake install shall be screwed through the face and into the existing roof framing at least 1-1/2” into the existing roof decking and framing (see illustration).

d. POLMER MODIFIED BITUMINOUS SELF-HEALING WATERPROOF UNDERLAYMENT MEMBRANE (such as Ice & Water Shield): To be installed by the contractor on top of the new roof decking as a continuous layer per manufacturer’s instructions underneath the shingles or shakes to be installed. Contractor shall supply NPS with product and installation information for pre-purchase approval.

e. CONTINUOUS VENTILATION LAYER: Cedar Breather or equivalent substitute shall be installed as a ventilating layer between the underlayment membrane and shingles. Note: If shakes are used, there will be an additional step of adding construction felt between shake layers.

f. SHINGLES/SHAKES: Shingles or shakes shall be premium grade, edge grain Alaskan yellow cedar, or better, of 18” or 24” length. Shingles or shakes shall come with a minimum 20-year Mill warranty. Shingles or shakes shall come pressure-impregnated by the manufacturer with Class B or better fire-retardant. Installed shingles shall be a minimum of 4” wide and a maximum of 10” wide. Wider shingles may be set aside for use as cut gable pieces. Contractor shall supply NPS with product information for pre-purchase approval. All new shingles or shakes installed must match existing materials in appearance. These structures are being considered for historic status. It is possible that split cedar shakes will be required to meet appearance requirements. Contractor shall supply NPS with product and installation information for pre-purchase approval.

g. EDGE TREATMENTS: Contractor to install drip edge flashing, trim, etc., as needed to return the final appearance to a reasonable likeness of the pre-construction appearance. If needed, a new piece of 1x trim may be added to conceal foam edges. All new edge treatment materials installed must match existing materials in color, finish type, and composition.

Contractor shall supply NPS with product and installation information for pre-purchase approval.

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RE-SHINGLING

a. SURFACE PREPARATION (tear-off): Existing shakes and underlayment to be removed to the extent practicable. Remove all existing materials and fasteners to existing roof decking. Six roofs.

b. FOAM AND NEW ROOF DECKING INSTALLATION: Complete installation. Materials per “MATERIAL SPECIFICATIONS” above. Six roofs.

c. UNDERLAYMENT MEMBRANE/CONTINUOUS VENTILATION/SHINGLES OR SHAKES/EDGE TREATMENT: Complete installation. Materials per “MATERIAL SPECIFICATIONS” above. Six roofs.

Special Conditions

The Contractor may use such equipment as required for electrical power generation on the job site in accordance with all applicable federal, state and local environmental safety and health regulations.

These A-frames may be occupied NPS employee housing during the potential Period of Performance (Saturday, May 1, 2021 to Wednesday, June 30, 2021).

Contractor work hours on these A-frames shall be limited to 7:00 AM to 5:30 PM, Monday through Saturday. Changes to these work hours and days will require prior approval by NPS.

The Contractor may station a two self-contained housing trailers or recreational vehicles only at Toklat Road Camp for the duration of this work at two NPS-supplied RV sites with sewer, water, and electric hook-ups at no charge for the duration of the project (to be removed no later than Wednesday, June 30, 2021). Additional sites may be available. The Contractor must supply all additional utilities (such as propane) and services such as laundry, shower, toilets, recreation, telephone service, and cooking facilities for Contractor staff.

Contractor staff will not be able to use Toklat Road Camp facilities.

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There is no cellphone coverage at the job site or at Toklat Road Camp.

Emergency phone service is available at Toklat Road Camp or the Contractor may provide own telephone service through private dish services.

There is a Road Permit system for all service vehicles traveling on the Park Road. Truck/trailer combinations of over 22’ are subject to further restrictions (time of travel and potential pilot vehicle requirements).