GRD VOR PVC Membrane_Stainless Steel Mesh Roof Spec.pdf

Department of Transportation Federal Aviation Administration

04/28/2020

Submitted By:

Shane C. Harvey ASO-Engineering Services Infrastructure

FAA-GRD-1505934

Specification For

“PVC MEMBRANE STAINLESS STEEL MESH ROOF

SYSTEM ON VORTAC FACILITY”

GREENWOOD, SC

TABLE OF CONTENTS

DIVISION 1 - GENERAL REQUIREMENTS --------------------------------------------------------- 4

SECTION 1A - SUMMARY OF THE WORK ---------------------------------------------------------------------------- 4 1A.1 General ------------------------------------------------------------------------------------------------------------------------------ 4 1A.2 Scope of Work --------------------------------------------------------------------------------------------------------------------- 4 1A.3 Coordination ----------------------------------------------------------------------------------------------------------------------- 4 1A.4 Sanitary Facilities ----------------------------------------------------------------------------------------------------------------- 5 1A.5 Materials ---------------------------------------------------------------------------------------------------------------------------- 5 1A.6 Material Storage ------------------------------------------------------------------------------------------------------------------ 5 1A.7 Ingress and Egress to Work Areas ------------------------------------------------------------------------------------------ 5 1A.8 Cleaning ----------------------------------------------------------------------------------------------------------------------------- 5 1A.9 Pre-Construction Meeting ------------------------------------------------------------------------------------------------------ 5 1A.10 Project Drawings -------------------------------------------------------------------------------------------------------------- 6 1A.11 Site Visit ------------------------------------------------------------------------------------------------------------------------- 6 1A.12 Contractor’s Warranty -------------------------------------------------------------------------------------------------------- 6 1A.13 Manufacturer's Warranty ---------------------------------------------------------------------------------------------------- 6 1A.14 Contractor's Liability ---------------------------------------------------------------------------------------------------------- 7 1A.15 Workmanship ------------------------------------------------------------------------------------------------------------------- 7 1A.16 Work Permits ------------------------------------------------------------------------------------------------------------------- 7 1A.17 Asbestos Free Certification ------------------------------------------------------------------------------------------------- 7 1A.18 Hazardous Material and Safety -------------------------------------------------------------------------------------------- 7 1A.19 Protection of Work and Property ------------------------------------------------------------------------------------------ 8

DIVISION 2 - SITE WORK -------------------------------------------------------------------------------- 8 SECTION 2A - EQUIPMENT REMOVAL -------------------------------------------------------------------------------- 8

2A.1 Scope of Work --------------------------------------------------------------------------------------------------------------------- 8 2A.2 TACAN Antenna Removal ------------------------------------------------------------------------------------------------------ 9 2A.3 Fiberglass Antenna Shelter Removal ------------------------------------------------------------------------------------- 10 2A.4 Azimuth Positioner Brackets ------------------------------------------------------------------------------------------------- 10 2A.5 Protection of Roof during Construction ----------------------------------------------------------------------------------- 11

DIVISION 6 - WOOD ------------------------------------------------------------------------------------- 11 SECTION 6A - DECKING -------------------------------------------------------------------------------------------------- 11

6A.1 Scope of Work ------------------------------------------------------------------------------------------------------------------- 11 6A.2 Materials -------------------------------------------------------------------------------------------------------------------------- 11

DIVISION 7 – THERMAL & MOISTURE PROTECTION --------------------------------------- 11 SECTION 7A - NOT USED ------------------------------------------------------------------------------------------------ 11 SECTION 7B – UNDERLAYMENT -------------------------------------------------------------------------------------- 12

7B.1 Scope of Work ------------------------------------------------------------------------------------------------------------------- 12 7B.2 Materials -------------------------------------------------------------------------------------------------------------------------- 12 7B.3 Installation ------------------------------------------------------------------------------------------------------------------------ 12

SECTION 7C – NOT USED ----------------------------------------------------------------------------------------------- 12 SECTION 7D – SINGLE-PLY PVC ROOFING MEMBRANE ----------------------------------------------------- 12

7D.1 Scope of Work --------------------------------------------------------------------------------------------------------------- 12 7D.2 Materials ----------------------------------------------------------------------------------------------------------------------- 12 7D.3 Caulking for PVC Membrane --------------------------------------------------------------------------------------------- 14 7D.4 Weather Limitations -------------------------------------------------------------------------------------------------------- 14 7D.5 Quality Assurance ----------------------------------------------------------------------------------------------------------- 14 7D.6 Product Delivery and Storage -------------------------------------------------------------------------------------------- 18 7D.7 Membrane Installation------------------------------------------------------------------------------------------------------ 19 7D.8 Weather Protection --------------------------------------------------------------------------------------------------------- 21 7D.9 Field Quality Control -------------------------------------------------------------------------------------------------------- 21

DIVISION 10 – SPECIALTIES ------------------------------------------------------------------------- 22 SECTION 10A - ANTENNA SHELTER INSTALLATION ----------------------------------------------------------- 22

10A.1 Scope of Work --------------------------------------------------------------------------------------------------------------- 22 10A.2 Inspection --------------------------------------------------------------------------------------------------------------------- 22 10A.3 Materials ----------------------------------------------------------------------------------------------------------------------- 22 10A.4 Shelter Door and Louvers ------------------------------------------------------------------------------------------------- 22 10A.5 Shelter Repair if damaged during removal and/or installation --------------------------------------------------- 22 10A.6 Resin Application (If needed for Repair of damage area) --------------------------------------------------------- 23 10A.7 Paint Antenna Shelter ------------------------------------------------------------------------------------------------------ 23 10A.8 TACAN Mounting Fixture Painting: N/A -------------------------------------------------------------------------------- 23 10A.9 TACAN Antenna Unit Painting: N/A ------------------------------------------------------------------------------------- 24

10A.10 Inspection -------------------------------------------------------------------------------------------------------------------- 24 10A.11 Antenna Shelter Base Gasket ------------------------------------------------------------------------------------------ 24 10A.12 Antenna Shelter Installation --------------------------------------------------------------------------------------------- 24

SECTION 10B – AZIMUTH (KEYSTONE) POSITIONER BRACKETS ----------------------------------------- 25 10B.1 Azimuth Installation --------------------------------------------------------------------------------------------------------- 25

SECTION 10C - COUNTERPOISE GROUNDING ------------------------------------------------------------------ 25 10C.1 Scope of Work --------------------------------------------------------------------------------------------------------------- 25 10C.2 Counterpoise Grounding Materials ------------------------------------------------------------------------------------- 25 10C.3 Welding Procedures -------------------------------------------------------------------------------------------------------- 25

SECTION 10D – STAINLESS STEEL MESH COUNTERPOISE ----------------------------------------------- 26 10D.1 Scope of Work --------------------------------------------------------------------------------------------------------------- 26 10D.2 Materials ----------------------------------------------------------------------------------------------------------------------- 26

Note: Divisions 3, 4, 5, 8, 9, 11 through 14, 15 and 16 are not used.

DIVISION 1 - GENERAL REQUIREMENTS

SECTION 1A - SUMMARY OF THE WORK

1A.1 General This specification, along with project drawings, codes and standards specifies the technical requirements of the Federal Aviation Administration (FAA) to install a PVC single ply roof system, and stainless steel mesh counterpoise system on a VORTAC facility.

1A.2 Scope of Work The work consists of, but is not limited to, the following:

1) Wrap VOR equipment racks with polyethylene for the duration of construction.

2) Remove and replace the 16 ft. fiberglass antenna cone shelter.

3) Survey/mark, remove and reinstall the 16 azimuth antennas. The positioner brackets and bracket supports shall be removed. All sixteen (16) brackets and supports will be reused.

4) Reinstall the 16 azimuth positioner brackets and bracket supports.

5) Install a stainless steel mesh roof over the entire roof surface including inside the fiberglass antenna shelter.

6) Install flashing around perimeter of roof counterpoise.

7) Install ¾” tongue and groove plywood surface over mesh.

8) Install single-ply fully adhered, PVC roofing membrane with a minimum 10 year warranty.

9) Install SarnaTred (or equal) walkway tread area around the cone from the main access ladder supports at the roof edge, as indicated on the drawings.

10) Remove 120V ground fault interrupter A/C receptacle in the antenna shelter (if applicable).

11) Supply and install one continuous tarpaulin 56 feet in diameter to cover and protect the roof during inclement weather during construction. Diameter of roof is 52’-6”.

1A.3 Coordination All coordination between the contractor and the FAA shall be through the Contracting Officer (CO) and the CO’s designated Contracting Officer’s Representative, (COR).

1A.4 Sanitary Facilities Sanitary facilities are not available at the site. The contractor shall provide temporary toilet facilities as required for his workmen. Temporary toilet facilities shall be of the type approved by the local governing body. The location of the toilet facilities shall be as directed by the COR.

1A.5 Materials The contractor shall furnish all materials, equipment, and labor to complete all contract requirements, the use of brand names or equal products in this specification does not constitute a requirement that they are the only materials which meet the specifications in this contract.

They are used as an illustration of known acceptable sources or products.

If a brand name product is used in the drawings or Specifications, it should be regarded as a “known acceptable source". The use of the term “known acceptable source” and “brand name or equal” in referencing a specific product or manufacturer is not intended to indicate a preference for the products mentioned, but indicates the quality and characteristics of products that will meet the Government requirements. Should the Contractor decide to use a product other than that identified as a “known acceptable source” or “brand name or equal”, the Contractor shall provide a submittal for this product. This does not relieve the Contractor from providing submittals for products or materials required in other sections of this Specification.

1A.6 Material Storage The contractor shall store all materials in a manner to protect them from all elements of the weather.

No contractor furnished materials shall be stored inside the FAA equipment building or engine generator room.

1A.7 Ingress and Egress to Work Areas Ingress and egress to the work areas shall be as directed by the COR. Security precautions against unauthorized site and building entrance shall be maintained. The contractor shall keep all vehicles, working equipment and materials within the leased boundaries of the access road and site plot.

1A.8 Cleaning

1) Work Area: The contractor shall keep the work area clean and proper condition. All rubbish and waste resulting from the execution of the work shall be removed at the end of each day or as directed by the COR. All dumpsters shall be covered.

2) Waste Packing Material: Immediately after unpacking, all packing material, case lumber, excelsior, or other rubbish, flammable or otherwise, shall be removed from the building and the premises.

3) Final Clean-Up: Upon completion of work, and before final inspection, the contractor shall remove his working tools, equipment, debris, rubbish, and unused materials from the building site.

4) Disposal: Disposal of rubbish, debris, and gravel will be off the site at the contractor's expense or as directed by the COR.

1A.9 Pre-Construction Meeting The contractor shall attend a Pre-Construction Meeting prior to starting work at a location agreed upon between the contractor and the Contracting Officer.

1A.10 Project Drawings The following signed construction drawings form a part of specification and are applicable to the extent specified herein. If any conflict exists between drawings and the specifications, the specifications shall govern.

Drawing Date Title

GRD-1505934-G001 Cover Sheet

GRD-1505934-G002 Drawing Index, Abbreviations, and Legend

GRD-1505934-G003 General Notes and GFM List

GRD-1505934-D001 Demolition Plan

GRD-1505934-A001 Roof Plan Layout/Counterpoise Replacement and Grounding

GRD-1505934-A002 Roof Edge Flashing Details and Grounding

GRD-1505934-A003 Antenna Enclosure Plan and Details

GRD-1505934-A004 Walkway Layout and Ladder Supports

GRD-1505934-S001 Monitor Antenna Support Assembly

GRD-1505934-S002 Alternate Monitor Antenna Support Assembly

GRD-1505934-E001 Grounding Details

1A.11 Site Visit Bidders are encouraged to visit the site and carefully examine the areas in question as to conditions that may affect proper execution of the work. All dimensions and quantities shall be determined or verified by the contractor. No claims for extra costs will be allowed because of lack of full knowledge of the existing conditions. To arrange for a site visit contact (XXX)-XXX-XXXX.

1A.12 Contractor’s Warranty

The FAA’s Legal Counsel had made the determination in the past that our standard is one year material and workmanship, except for extended warranties; i.e., roofs.

1A.13 Manufacturer's Warranty The single-ply PVC membrane roof system shall be guaranteed against defects by the manufacturer and be leaking free for a period of 10 years after completion. This warranty shall identify the FAA as the owner of the facility and shall protect the FAA from all costs of repairing leakage resulting from defects in the single-ply PVC system. The location of the facility and the effective starting date of the warranty shall be indicated. Final contract payment will not be released until receipt of the written warranty from the contractor.

1A.14 Contractor's Liability Damage to existing facilities and equipment caused by the contractor shall be reported to the COR without delay. The contractor will be responsible for repairing, or having repaired, all damage of the building or equipment at the contractor's expense. All repairs shall be accomplished to the satisfaction of the COR.

1A.15 Workmanship All work shall be accomplished by experienced workers in accordance with the highest standards of the various work trades involved.

1A.16 Work Permits The cost of all construction and working permits required by local and state agencies shall be included in the contractor’s cost proposal.

1A.17 Asbestos Free Certification The Contractor shall provide to the Contracting Officer-(CO) a signed statement stating that to the best of his/her knowledge, no asbestos-containing building materials were used during the re-roofing of this facility.

The FAA will sample the suspect material to verify that no asbestos-containing material was utilized. This testing shall be performed at the expense of the FAA prior to construction on the facility. If asbestos-containing material is subsequently found during the sampling of the building materials, the Contractor shall remove and replace the product or material at his/her expense.

The Contractor shall submit to the COR, Material Safety Data Sheets (MSDS), prior to construction, for all materials and/or products to be utilized during the course of the project accomplishment.

During the course of the project, both the COR and the Contractor shall routinely check products utilized on-site to ensure only products which have had MSDS submitted are utilized. Copies of all MSDS shall be turned over to the local FAA office for their records.

1A.18 Hazardous Material and Safety Existing terne-coated metal roof may contain LEAD. The contractor shall provide workers protection per OSHA 29 CFR 1926.62.

The contractor shall be responsible for safety on the work site. It is the responsibility of the contractor to eliminate hazards which may result in tripping, electrical shock, fire, falling objects, environmental hazards, vehicular accidents etc. The contractor shall comply with all safety precautions required by OSHA. The contractor shall have two l5 lb. Class B and C fire extinguishers at the work area through the progress of welding, soldering, metal cutting, or any other process involving a spark or fire hazard.

1A.19 Protection of Work and Property

1) Scope of Work Provide a protective moisture barrier plastic cover over all electronic equipment, control panels, and power panels.

2) Materials

a) Polyethylene film sheeting, six mils thick, transparent, and in width suitable to adequately cover the equipment.

b) Duct tape used to attach the polyethylene film sheeting shall be waterproof sealing type.

3) Installation Carefully cover the equipment so that no water can enter the cabinets and damage the equipment. Equipment in service which generates heat and requires ventilation shall have a wood frame constructed above the equipment and covered with polyethylene membrane. All temporary polyethylene covering shall be approved by the COR.

DIVISION 2 - SITE WORK

SECTION 2A - EQUIPMENT REMOVAL

2A.1 Scope of Work The fiberglass antenna shelter and azimuth antennas shall be removed from the building roof prior to installation of the new single-ply membrane roof. The TACAN antenna and VOR antenna shall be removed by the contractor with FAA oversight. Remove all existing terne-coated metal pans, cleats, nails, rosin paper, and base felts from the existing wood deck and dispose of. Temporary covering over the roof shall be provided until new roof is installed and antenna shelter has been reinstalled.

The temporary roof covering shall be the tarpaulin specified in this specification which shall be supplied by the contractor.

2A.2 TACAN Antenna Removal

1) Before the TACAN antenna is removed, all antenna cables will be disconnected by the FAA and pulled back into the building or protected. Likewise, the VOR antenna system will be removed by the FAA from the antenna pedestal mounting support and placed in storage.

2) The TACAN antenna is approximately 4 feet in diameter by 7 feet high and is mounted on top of a 4 foot diameter by 2 feet high steel top mounting fixture which sets on top of the fiberglass antenna shelter. The TACAN antenna weighs approximately 800 pounds.

3) The TACAN antenna shall be removed first. Attach the FAA provided sling to the

TACAN antenna and crane. The antenna rests on a gasket and is bolted to the top mounting fixture with eight bolts through an internal base flange. Carefully remove hold-down bolts after sling is in position and lower the TACAN antenna to grade for safe storage on site. The entire removal operation is to be accomplished under the direction of the FAA electronics specialists who will be on site for these operations. Minimum two days advance notice for removal shall be given the COR. The orientation of the TACAN collar should be noted.

4) The TACAN antenna shall be stored on site where directed by the COR. The antenna shall be temporarily bolted to a wood frame and crate (dunnage) provided by the contractor. The assembly shall remain attached to the crane until bolting to the wood frame is accomplished.

5) Contractor shall prep collar including cut caulking around collar and properly sling before unbolting

2A.3 Fiberglass Antenna Shelter Removal

1) The orientation of antenna shelter door shall be noted removal and in the field to assure reinstallation in the same relative position.

2) In addition to the lag bolts holding the antenna shelter to the roof, waterproofing material at the base was also incorporated in the original construction that will contribute to difficulty in removing the shelter. Such materials will include a circular gasket under the antenna shelter, flashing materials adhering to the roof and antenna shelter, and various caulking and sealant beads at this juncture. Carefully cut such materials free from the antenna shelter using knives and flush-cut surface saws, in such manner that the shelter is in no way damaged. Carefully remove the heavy residue from the shelter ensuring not to damage the fiberglass.

3) Hoist cables shall be secured to the antenna shelter system before hold-down bolts are removed to insure that shelter will not blow over in the wind. Shelter shall be carefully hoisted in an approved manner from the building roof to temporary storage on grade.

Place antenna shelter on wood blocking and boards of sufficient area such that the weight of the antenna shelter is distributed over at least 50% of the area of the base flange to preclude damage to the relatively brittle shelter.

4) Immediately after placement of the antenna shelter on grade, it shall be anchored with at least four guy wires or ropes and posts driven into the ground to preclude this shelter from being blown over by the wind. This precaution is emphasized due to its occurrence in the past at substantial cost for replacement.

2A.4 Azimuth Positioner Brackets

1) Subsequent to removal of the 16 azimuth positioner brackets, the monitor antennas and connecting cables will be disconnected and removed by the FAA. Do not remove the North bracket (identified by the COR) until a registered land surveyor has established a north bracket offset. The antenna brackets consist of 5" x 5" x 3/8" x 6" long aluminum angles fastened to the roof deck with four mechanical fasteners.

Keystone (trapezoidal face) plates are attached to the azimuth positioner brackets which support the antennas by a wedging action. All of the azimuths positioner brackets will be reused.

2A.5 Protection of Roof during Construction Temporary covering over the roof shall be provided until new roof is installed and antenna shelter has been reinstalled. The temporary roof covering shall be the tarpaulin specified in this document which shall be supplied by the contractor.

DIVISION 6 - WOOD

SECTION 6A - DECKING

6A.1 Scope of Work After the old roofing has been removed, the contractor shall replace all deteriorated 2x6 decking, wood framing and fascia material as directed by the COR.

6A.2 Materials

1) Lumber: Lumber shall be pressure treated with preservative Chromate Copper Arsenate

(CCA) and dried after treatment. Retention of preservative shall not be less than 0.40 lbs./cubic foot.

2) Decking: Decking shall be treated 2 x 6 T&G to (dimensionally) match existing.

3) Sheathing: Sheathing shall be nominal ¾” treated plywood and ¾” treated plywood sheathing inside the cone area

4) Nails: Nails for decking shall be 8D common nails.

5) Fasteners: The wood nailers shall be attached to the existing decking with 302, 304, or 410 stainless steel fasteners or fasteners specially coated to be used in CCA treated lumber as indicated on the drawings. Furring strips shall be affixed to existing nailers, fascia, and one to another utilizing 1/4"Ø x 2 1/2" Long “Zinc-Plated Steel” Lag Screws, or equal.

DIVISION 7 – THERMAL & MOISTURE PROTECTION

SECTION 7A – NOT USED

SECTION 7B – UNDERLAYMENT

7B.1 Scope of Work Install underlayment covering on top of the main deck.

7B.2 Materials

1) Fasteners: As recommended by underlayment manufacturer.

2) Underlayment: butyl underlayment, grace ultra or equal and must be compatible with the stainless steel mesh counterpoise.

7B.3 Installation Prior to installation, remove all oil, dirt, and other debris from the roof deck. Ensure loose or protruding nails are removed or hammered down. All surfaces shall be dry and free from frost. Lay down one layer of underlayment and secure as required.

SECTION 7C - NOT USED

SECTION 7D - SINGLE-PLY PVC ROOFING MEMBRANE

7D.1 Scope of Work The work covered by Section 7D is for a fully adhered, 0.080 inch thick, single-ply Polyvinyl Chloride (PVC) membrane with hot air welded seams.

7D.2 Materials:

1) Single-Ply Membrane:

Membrane shall be a fiberglass-reinforced flexible PVC sheeting, 0.080 inches thick, such as G 410 as manufactured by Sarnafil, Inc., (Tel. 1-800-451-2504), or approved equal. PVC membrane used for flashing and roofing shall be fully adhered with hot air welded joints. Color shall be white. The proposal of another manufacturer's product requires the following: Membrane manufacturer's Catalog and Specification Data including descriptions and detailed application instructions, standard installation detail drawings, product characteristics, physical properties, a copy of the minimum 10 year warranty. Acceptable Alternate Manufacturers:

Durolast, Truco

For Flashing: G410-12, 48 mil and 60 mil (1.2 mm), thermoplastic membrane with fiberglass reinforcement.

For The Roof: G410-20, 80 mil (2.0 mm), thermoplastic membrane with fiberglass reinforcement.

Certified Polymer Thickness

Membrane manufacturer is to certify that the polymer thickness is of the polymer thickness specified. Certification is to be signed by the membrane manufacturer’s quality control manager. ASTM +/- tolerance for membrane thickness is not accepted.

Color of Membrane

Energy Smart (white), initial reflectivity of 0.83, initial emissivity 0.90, solar reflective index (SRI) of >104.

Typical Physical Properties (1)

Parameters

ASTM

Test Method Minimum ASTM

Requirement Sarnafil Typical

Physical Properties

Reinforcing Material - Fiberglass Overall Thickness, min., inches (mm) D638 0.0805 (1.14) [0.08 inches)] Tensile Strength, min., psi (MPa) D638 1500 (10.4) 1600 (11.1) Elongation at Break, min. (machine x tranverse) D638 250% / 230% 270% / 250% Seam strength(2), min. (% of tensile strength) D638 75 80 Retention of Properties After Heat Aging D3045 - -

Tensile Strength, min., (% of original) D638 90 95 Elongation, min., (% of original) D638 90 90

Tearing Resistance, min., lbf (N) D1004 10 (45.0) 14 (63.0) Low Temperature Bend, -40º F (-40º C) D2136 Pass Pass Accelerated Weathering Test (Xenon Arc) D2565 5,000 Hours Pass

Cracking (7x magnification) - None None Discoloration (by observation) - Negligible Negligible Crazing (7 x magnification) - None None

Linear Dimensional Change D1204 0.10 % 0.02% Weight Change After Immersion in Water D570 ± 3.0% 2.5% Static Puncture Resistance, 33 lbf (15 kg) D5602 Pass Pass Dynamic Puncture Resistance, 7.3 ft-lbf (10 J) D5635 Pass Pass

*Failure occurs through membrane rupture not seam failure.

2) Flashing Material:

a) Membrane coated flashing material shall be "PVC coated metal ", G 410- L, 25 gauge galvanized steel, coated with a 0.02 inch thick coating of PVC film or approved equal. This material shall be used for edge flashing around the perimeter of the counterpoise roof and bottom retaining strip.

3) Protection Mat:

a. SarnaTred polyester-reinforced PVC protection mat, or approved equal, shall be installed where shown on the project drawings to protect the roofing membrane in high traffic areas.

4) Adhesives:

a) 2170 solvent-based, elastomeric adhesive or approved equal shall be used to attach the membrane, polyester felt and tread protection mat to the substrates specified.

b) 2121 water-based dispersion adhesive or approved equal shall be used to apply a silica sand non-slip surface to the walkway membrane. This product must be protected from freezing.

c) 11FC and Primer 449: The 11FC is one-component polyurethane construction adhesive. The primer is clear, solvent base primer.

7D.3 Caulking for PVC Membrane Caulking to be used on the flashing in the fiberglass antenna shelter, between the antenna shelter base gasket and the single-ply membrane and installing the ladder deck supports to the roof surface, shall be chemically compatible with the PVC membrane. The following caulking/sealants are accepted, based on chemical compatibility with PVC membranes:

Monolastomeric, one-part acrylic, as manufactured by Tremco.

Silpurf, one-part silicone sealant, as manufactured by General Electric Company, or equal by Dow Corning.

GACO AS-3, one-part silicone sealant, as manufactured by Gates Engineering Company.

7D.4 Weather Limitations Roofing or insulation materials shall not be applied until the ambient temperature is above 50 deg F with no signs or forecast for rain. Roofing materials shall not be applied when there is excessive moisture in the air causing wet or damp surfaces.

7D.5 Quality Assurance

1) Approved roofing system shall have a Class I-90 wind uplift rating.

2) Applicators shall be trained and qualified for installation of the approved roofing system.

3) The roofing contractor shall be a firm with a minimum of two years experience with the approved roofing system.

4) The Contractor shall be required to have the manufacturer’s technical representative visit the site one day at the beginning of the roof installation and one day at the end of the project.

5) The technical representative shall advice the contractor and COR concerning the effectiveness and acceptability of the roof system that the contractor has proposed and the implemented method of welds.

6) The technical representative and contractor shall test all the welds in the presence of the COR. All welds shall be tested for continuity by running a rounded edge screwdriver along the membrane joints after cooling. Any discontinuities shall be re-welded. Positive evidence of good welding is characterized by an uninterrupted extrusion of melted black material from the joint.

7) The Resident Engineer (COR), shall require the contractor to sample the welded seams by cutting two-inch wide cross-section samples of the welded seams. Correct welds will display failure from shearing of the membrane prior to separation of the weld. The Contractor, at no additional charge to the FAA, shall patch each test cut.

Expect to test each seam done at least twice.

8) The technical representative shall confirm that the finished product will receive the specified manufacturer’s warranty; and send a copy of their site visit report to the COR.

9) The technical representative shall inspect the roof just before installation of the walkway to assure that the roof is watertight. All welds shall be tested and sampled for continuity.

10) Seam Probing - The Applicator is responsible for probing of all seams.

11) After the membrane has cooled from hot-air welding, check the seams for continuity using a rounded flat head screwdriver or other acceptable tool (seam probe). Firmly press the edge of the screwdriver firmly into the seam area while moving it along the seam. Mark areas where the probe can penetrate the seam for repair.

Quality Assurance Procedures

Seam Samples — A minimum of 3 seam test samples, each approximately 1 inch wide, must be taken on a daily basis by the Roofing contractor. Samples should be taken at the start of each day’s welding, when they stop for brake, and when starting back up after lunch breaks.

1. Allow the membrane to cool off after hot-air welding. The sample is taken by cutting out a cross-section of the seam approximately one-inch wide by eight inches long with the seam in the center.

2. Using Vice-Grips or pliers, pull the seam apart. The seam is considered acceptable when the top membrane separates within itself.

3. Repair the sample area by hot-air welding a patch that is at least 3 inches larger than the opening in all directions.

Samples must be dated, and welded over the patch area for the technical representative.

Example of a hand weld that has passed the peel test.

Example of Machine failed peel test.

View of a good peel test; fiberglass reinforced and polyester reinforced membranes.

7D.6 Product Delivery and Storage All products delivered to the site shall be in original unopened containers. Store membrane rolls lying down, fully protected from moisture. All stored materials shall be protected from damage during construction by the contractor.

7D.7 Membrane Installation

1) Inspection: The roofing contractor shall examine the surface scheduled to receive the membrane for defects that will adversely affect the execution and quality of work.

2) Preparation: The surface of the plywood and other surfaces to receive membrane shall be dry and free from dust or loose particles which would interfere in obtaining proper adequate bond.

3) Application:

View of the roof drip edge area

a) Lap Seams Shingle Fashion: The VOR counterpoise roof slopes from the fiberglass antenna shelter to the outer edge in all directions. The contractor shall begin at the south edge of the counterpoise roof and lay the PVC membrane east-west towards the center of the roof and stop when reaching the center.

Then the contractor shall begin at the north edge of the counterpoise roof and lay the PVC membrane east-west working towards the center of the roof and finish up with a closure strip across the center. This will allow the roof to drain over the laps in a shingle fashion. All references to north-south and east-west are based on the azimuth positioner brackets, which are set on magnetic bearings. See the project drawings for details.

b) Fully Adhered Membrane: Carefully follow the PVC membrane manufacturer's instructions for using adhesive to install a fully adhered membrane system. The membrane shall be smooth and free from wrinkles, air bubbles, puckers, and similar irregularities which leave an unsightly appearance. Membrane laid that is not in accordance with this contract, shall be replaced or repaired, at the Contractor’s cost, in a manner that is acceptable to the manufacturer, in order to pass the required inspection for the required manufacturer’s extended warranty. The membrane shall be installed in strips as long as possible in order to minimize the number of end laps and short pieces.

c) Joining Overlapped Roof Membrane: All joints shall be made by hot air welding with electric hot-air welding equipment meeting the membrane manufacturer’s approval. Lap areas shall be a minimum of 6 inches wide. No adhesive shall be present within the lap area. Machine welding shall be used on all seams where possible. Hand welding shall only be used where seams are not accessible for machine welding.

d) Machine Welding: Machine welding shall be achieved by the use of an automatic welding machine approved by the membrane manufacturer. When using this equipment, the manufacturer's instructions shall be followed and local code for the electric supply, grounding, and overcurrent protection observed. The automatic welding machine requires 218 to 230 volts at 30 amps. (The use of a contractor-furnished portable generator is recommended.)

e) Hand Welding: The equipment shall be allowed to warm up for at least one minute prior to the start of welding. The lap shall be welded every three feet to hold the material in place. The back edge of the lap shall be welded with a thin, continuous weld to prevent loss of hot air during the final welding. The hot-air nozzle shall be inserted into the lap, keeping the welding equipment at a 45 degree angle to the side lap. Once the proper welding temperature has been reached and the material starts to flow the hand roller shall be applied at a right angle to the welding bun and pressed lightly. For straight laps, the 1 1/2 inch wide nozzle shall be used. For corners and compound connections, the 3/4 inch wide nozzle shall be used.

f) Roof Edge Flashing: The roof edge fascia flashing and bottom retaining strip shall be fabricated from pvc metal clad metal or approved equal. Flashing details are shown on the project drawings. The roof edge fascia flashing shall be attached to the solid wood nailers with two rows of #12 x 3 1/4 inch long Buildex Roofgrip Fasteners, with #3 Phillips Head, set 3 inches on center in a staggered pattern as shown on the drawing details.

7D.8 Weather Protection

When inclement weather forces a work stoppage or when the contractor leaves the work site at night, over weekends or any other time, the roof shall be covered with the specified tarpaulin securely tied down and weighted with sand bags or similar means to prevent the wind from blowing the tarpaulin off. It shall be the responsibility of the contractor to insure the tarpaulin is leak free. Roofing materials damaged from wind or rain during construction shall be replaced at the contractor's expense.

7D.9 Field Quality Control Test all welds for continuity by running a screwdriver along the membrane joints after cooling. Re-weld any discontinuities by and uninterrupted extrusion of melted black material from the joint.

Cut a one inch wide strip perpendicular to the seam at the each seam of the roof and test the condition of the seam and patch the test area. Refer to section 7D.5 Quality Assurance.

INSTALLATION OF A PVC MEMBRANE/STAINLESS STEEL MESH ROOF SYSTEM ON VORTAC FACILITY GREENWOOD, SC Spec. No. FAA-GRD-1505934

DIVISION 10 – SPECIALTIES

SECTION 10A - ANTENNA SHELTER INSTALLATION

10A.1 Scope of Work This section covers the requirements for installing the VOR fiberglass antenna shelter, on the new roof. The contractor is cautioned that the VOR fiberglass antenna shelter can be damaged with rough handling. Care must be exercised when working with the shelter to maintain its structural integrity. In addition, the following specifications cover the requirements to furnish all material, equipment, labor, and supervision to accomplish the work described in this specification.

10A.2 Inspection All phases of this work shall be approved by the COR.

10A.3 Materials

1) Caulking: Caulking shall be premium grade high-performance moisture cured, non-sag, and polyurethane-base elastomeric sealant 3M 5200 or approved equal.

2) Gaskets: All the shelter gaskets are GFM.

3) Lag Bolts: To secure antenna shelter. Contractor shall furnish new 3/8" x 3" long hex head stainless steel lag bolts and washers.

4) Fastening Strips: To prevent lag pull through. Located between lag washers and shelter base.

10A.4 Shelter Door and Louvers The contractor shall install the new gasket for the door after the shelter has been installed.

10A.5 Shelter Repair if damaged during removal and/or installation

All holes, cracks, damaged areas or areas where the protective resin coatings have worn away and have left the fiberglass surface exposed and weathered shall be repaired, as follows.

1) Cut away all ragged edges and corners from the damaged area of the panel to form an oval or round hole by using a router, rasp or other acceptable tool.

2) Feather the edge of the hole on the interior and exterior surface of the panel to a smooth, sloping contour approximately 3 inches beyond the edge of the hole.

3) Clean all abraded areas with solvent cleaner.

4) Cut fiberglass cloth patches approximately 2 or 3 inches larger than the hole formed in Step 1.

5) Apply premixed epoxy resin with a paint brush or spatula to the abraded surface and the feathered edge of the hole.

6) Position fiberglass cloth patch on exterior surface of panel, and brush resin on outside of patch and around edges to produce a filled surface free of air bubbles.

7) On the interior side of the panel, cut a fiberglass cloth patch to fit the dimensions of the hole. Cut sufficient number of additional patches, in increasing sizes (in 1/2 inch increments) to obtain a patch thickness (when impregnated with resin) of slightly greater thickness than the original pane. Finally, cut and apply one patch 2 inches larger in diameter than the preceding patch.

8) After the resin has completely dried, sand the repaired areas smooth with a fine grit sand paper.

10A.6 Resin Application (If needed for Repair of damage area) Combine and mix resin in accordance with the manufacturer's instructions. Use extreme caution in handling the catalyst and accelerator as they are toxic and highly reactive. Catalyst and accelerator ratios depend upon many factors, including application method (two-part pressure spray, roller, or brush), ambient temperature, and humidity. The resin may be applied by means of a two-part pressure pot, rollers, or brushes. Apply one coat of uniform thickness to entire surface to be refurbished. Where the fiberglass is exposed and loose glass fibers stick out n the surface, apply the resin in a manner which will cause the fibers to lie flat on the surfaces and become embedded in the resin coating. Required final coating shall be five to six mils in thickness on surfaces which are not deteriorated to the point where the fiberglass is exposed. Do not apply resin to surfaces which are evidently damp, or have had insufficient drying time at lower humidity levels to assure evaporation of moisture from cracks and porous areas. Allow at least 20 hours of curing time for resin coating on any particular area of the surface before sanding and application of paint.

10A.7 Paint Antenna Shelter If applicable, apply two coats of white, QC-Resin. The first coat acts as both a primer and base coat, and requires the addition of a small amount of Methyl Ethyl Ketone Peroxide (MEK-P) activator. Apply paint with a brush or roller. The first coat shall be worked in and spread to achieve a 5 mil dry film thickness (DFT). The second coat, which contains most of the white pigment shall be applied to achieve 7 mil DFT. Contact PPC Coatings to obtain these two separate coats that will be prepared specifically for this FAA application. Follow the manufacturer's instructions for mixing and pot life.

10A.8 TACAN Mounting Fixture Painting: N/A See 10A.7

10A.9 TACAN Antenna Unit Painting: N/A See 10A.7

10A.10 Inspection The COR will inspect the antenna shelters prior to storage and assembly of the old and new fiberglass shelters.

10A.11 Antenna Shelter Base Gasket Prior to installing the gaskets, the contractor shall mark a 5' - 0 1/2" radius (10' - 1" diameter) circular ring around the center of the roof with a felt tip ink pen in order to center the antenna shelter. After the centering reference circle has been marked, set the antenna shelter inside the circular marked line and center it as well as orienting the shelter in the same azimuth as it was before it was removed from the roof or as directed by the COR. After the shelter has been accurately positioned and approved by the COR, the contractor shall mark each bolt hole location and offsets as required on the single-ply membrane roofing with a suitable marker. The marks shall be in a circular pattern outlining each bolt hole. After all bolt holes have been marked, the shelter shall be moved in order to install the base gasket material. Pre-drill a 1/4" hole in the center of each bolt hole 1 1/2" deep. Apply a smooth even coat of caulking on the bottom side of the base gasket and set the gaskets in place. Keep the outer edge of the gasket approximately 1/4" from the edge of the antenna shelter to allow for a bead of caulking. The gasket may need to be trimmed on the outer edge by 1/4". Be extremely careful when trimming gasket to prevent cutting the single-ply membrane roof material. A strip of 20 gauge galvanized sheet metal can be placed under the gasket to prevent cutting the single-ply membrane. DO NOT CAULK THE TOP SURFACE OF THE GASKET except a small bead at each joint in the gasket.

10A.12 Antenna Shelter Installation

1) The antenna shelter shall be reinstalled atop the membrane in precisely the same location and orientation as existing before removal unless otherwise specified by the

COR.

2) Set the antenna shelter in place, mark the holes with the teepee in place, remove the teepee, drill ¼” pilot hole to a depth of 1 ½”.

3) Carefully hoist, align, and reset the antenna shelter on the roof with adhered gasket.

Install new stainless steel 3/8" x 3 inch long lag bolts and the fastening strips. Torque bolts equally to only such tightness to provide a watertight seal and not to an extent where fiberglass will shatter or the gasket deforms excessively. Tool the caulking around the outer and inner edges of the antenna shelter. Apply additional caulking if required to make a nice smooth bead.

SECTION 10B – AZIMUTH (KEYSTONE) POSITIONER BRACKETS

10B.1 Azimuth Installation A registered licensed surveyor shall set a transit over the building center point and project a line through the center of the north azimuth positioner bracket to a mark on a wood hub driven flush with the ground approximately 200 feet north of the VOR building. Guard the hub with a 1" x 2" x 5'-0" (+/-) wood stake with a red flag tied to the top of the stake. This work shall be performed with care and the COR shall check and approve the reference point before the azimuth positioner brackets are to be removed. When the monitor antennas are ready to be put back, the transit is set up, as previously referenced, to the wood hub, and scribe reference lines 22.5 degrees apart (relative to facility North) are placed near the edge of the roof at each of the 16 bracket locations using the transit to certify the proper reference of true north and angles. After turning the transit scope 360 degrees, the cross hair must align precisely with the wood hub starting mark. The azimuth positioner brackets must be evenly spaced at 22.5 degrees apart on centers.

SECTION 10C - COUNTERPOISE GROUNDING

10C.1 Scope of Work This section covers the requirements for grounding the new roof counterpoise.

10C.2 Counterpoise Grounding Materials

1) Stainless Steel Grounding Segments: The antenna pedestal mounting plate shall be grounded to the stainless steel mesh with four semi-circle segments fabricated from stainless steel; (22 GA stainless steel sheets).

2) Welding material- Shall be either solid core stainless steel for use with gas for MIG/ flux core Stainless steel for MIG or stainless steel stick for stick welding capable of type 304 stainless steel. It is suggested that the contractor use Flux core MIG techniques for this job due to the environmental factors of wind and small size of the mesh material. However, the contractor may choose whatever method works to obtain a clean consistent weld. Most VOR buildings have 208 three phase power but for this type of weld a Flux core 120v welder is recommended.

10C.3 Welding Procedures

1) Welding: Any welds rejected by the COR, shall be corrected before additional segments are placed. The stainless steel mesh counterpoise shall be soldered to the stainless steel antenna pedestal mounting plate grounding segments and the four grounding points at the counterpoise edge in the same manner.

2) Safety Protection: Flux is corrosive and can cause permanent eye damage if it comes in contact with the eye. Use chemical goggles or face shield when using the flux. If accidentally splashed into the eye, immediately flush the eye with plenty of clean water and get medical attention immediately. Swallowing the flux can cause severe damage to the esophagus and pylorus and requires immediate medical attention. Follow all safety procedures provided by the manufacturer when using the flux. Dispose of all unused flux following all federal, state and local regulations. Store flux in cool, well-ventilated area away from strongly alkaline materials.

SECTION 10D – STAINLESS STEEL MESH COUNTERPOISE

10D.1 Scope of Work The work covered by this section is for a Stainless Steel mesh counterpoise.

10D.2 Materials:

A. Fasteners:

1. Stainless steel Staples- minimum 16ga -2” leg 304 type

2. Welding material- Shall be either solid core stainless steel for use with gas for MIG/ flux core Stainless steel for MIG or stainless steel stick for stick welding capable of type 304 stainless steel. It is suggested that the contractor use Flux core MIG techniques for this job due to the environmental factors of wind and small size of the mesh material. However, the contractor may choose whatever method works to obtain a clean consistent weld. Most VOR buildings have 208 three phase power but for this type of weld a Flux core 120v welder is recommended.

B. Stainless Steel Sheet metal-304 type 22 ga for grounding plate and grounding segment fabrication.

C. 3/4” Diamond X 9 Gauge Stainless Steel Mesh (approx. 2100 sq.