These specs are only a general overview of the typical VOR Roof construction. These are for reference only. Each individual project will have its own specifications. 1
VOR Roof Projects IDIQ Solicitation DTFACN-11-R-00079 Typical Conventional VOR Facility Typical Doppler VOR Facility The Very High Frequency Omni-Directional Range (VOR) facility is a ground-based electronic system that provides azimuth information for both low & high altitude flight routes as well as airport approaches and is a critical component within the National Airspace System. The roofs of these facilities provide the interior equipment both a protective barrier from the elements as well as an electrically reflective surface required for the equipment to operate. Because the VOR must be totally removed from service for the duration of the roof replacement; work should be planned, scheduled, and completed in a manner so as to minimize downtime. VOR roofs consist of a circular roof deck (in diameters from 20 ft to 53 ft) and a centered fiberglass cone antenna shelter (approximately 16 ft high and 8 ft in diameter) which will be required to be removed prior to roofing. The cone is secured to the roof deck with approx. 32 bolts (about 3/8 in diameter). VORs utilize a system of monitor antennas for operation which are placed around the roof perimeter. Conventional VORs have 16 monitor antennas which typically attach to the vertical perimeter edge of the roof and can be easily removed for convenience/protection during the roof work. Doppler VORs have 50 side band/monitor antennas (about 22 ft out from roof center) that must remain in place during roof work and will require welding patches/flashing around the base of each antenna. Roofers shall have at least five years experience in installing the specified roof systems and shall also provide documentation from the roofing manufacturers showing that they are licensed for installation and therefore able to provide a fully warranted system as required. Work involved with the roofing projects will include one or up to all of the elements as outlined in the following sections. 1.00 EXAMINATION A. Examine roof deck to determine that it is sufficiently rigid to support materials, roofers and their mechanical equipment and that deflection will not strain or rupture roof components or deform deck. B. Verify that surfaces and site conditions are ready to receive work. Notify the COTR and correct defects in the substrate before commencing with roofing work. 2
C. The surface must be clean, dry, smooth, and free of sharp edges, fins, loose or foreign materials, oil, grease and other materials that may damage the membrane. All roughened surfaces, which could cause damage, shall be properly repaired before proceeding. 2.00 REMOVING ANTENNA CONE & EXISTING ROOF SYSTEM A. Remove and store antenna cone next to building. Provide a temporary platform frame/base for the cone to sit on to prevent damage and provide/install a temporary means of support to prevent the cone from tipping due to wind.. B. Removing existing roof system (edge metal, flashings, membrane, etc.). The Contractor may be required to remove the existing system down to the original structural decking. Inspect decking for water damage/rot and if damaged decking is found during removal of the roof system, the contractor will be required to submit a proposal for a change order to remove and replace the damaged areas of decking previous to installation of the new roofing. C. The contractor shall verify that the existing roof decking has sufficient slope to drain away from the antenna cone to the roof edge and will need to install sloped insulation if necessary to provide required runoff slope. (Approx. 3/16 per foot) D. Remove existing roof system components as specified and prepare surface of deck as recommended by manufacturer for installation of insulation. E. All surface voids of the immediate substrate greater than 1/4" wide must be properly filled with an acceptable insulation or suitable fill material 3.00 INTERIOR CEILING REPAIR/PAINTING A. VOR s typically have either acoustical tile drop-in ceilings or most commonly painted plywood ceilings. For facilities with interior ceiling water damage, Contractor shall either replace damaged ceiling tiles as designated to match existing or remove damaged sections of plywood ceiling and replace with matching materials. Paint new plywood surfaces with one coat of interior latex primer and one coat of interior latex finish coat of color to match existing ceiling. Paint/primer shall be Sherwin Williams or equal. 4.00 WOOD FASCIA BOARD REPLACEMENT A. Where required, Replace existing wood fascia and or soffit board with No.2 grade or better lumber and/or exterior grade plywood as applicable(remove and replace all attachments). Replace all fasteners with stainless fasteners of matching sizes. B. Apply 1 coat of Sherwin Williams, or equal exterior primer and 2 coats Sherwin Williams Duration or equal exterior acrylic latex paint using a roller or brush. 5.00 PAINTING AND PREP WORK General: Where required, prep and paint the VOR building surfaces as designated. All surfaces to be painted shall be properly cleaned and prepared in accordance with paint manufacturer s instructions. 3
A. Wood Decking (Underside of roof overhang): Scrape and/or sand blast wood surface to remove loose/peeling/chipping paint. Apply 1 coat of Sherwin Williams exterior primer and 2 coats Sherwin Williams Duration or equal exterior acrylic latex paint. B. Structural Steel (on underside of roof overhang): Minimum surface preparation is Hand or Power Tool Clean per SSPC-SP2 or SP3 followed by removal of all oil and grease from surface by Solvent Cleaning per SSPC-SP1. Apply 1 primer coat of Sherwin Williams Macropoxy 646 or equal 2-component primer. Apply 2 top coats of Sherwin Williams Acrolon 218 or equal. C. Fiberglass Antenna Shelter. Preparing the entire surface of the fiberglass cone by using an electric hand sander. Following sanding, the cone needs to be power washed. Water source may not be available in all sites, Contractor may have to supply his own water. Following power washing, the entire surface needs to be wiped down with solvent. Before painting, any deteriorated areas of joint sealant/caulking on the cone need to be removed and replaced. Paint must not have metal pigment such as aluminum, bronze, or lead; the only pigment to be used is titanium dioxide (white). Paint shall be Sherwin Williams Tile Clad Epoxy Paint or Glidden s Glid-thane II Acrylic Polyurethane Coating 6.00 BRACKETS FOR MONITOR ANTENNAS A. Remove, Clean, Sand (if needed) and reinstall 16 Brackets and Associated Hardware B. Fabricate and install 16 Gauge 4 x 6 Galvanized steel plated and Bolts for Bracket installation (Details will be provided) C. Re-install all Brackets in the same original location per new mounting requirements (Details will be provided) D. Drill hole on T&G deck and install a #6 AWG Solid Bare Copper (SBC) ground wire between each bracket and steel grating. Weld ground wire to grating and attach the opposite end to bracket using stainless steel bolt and bronze ground lug. 7.00 LADDER SAFETY ANCHORS A. Fabricate and install ladder safety anchors per details on the drawing. Center below ladder support brackets at the top of the fiberglass antenna shelter and space approximately 90 degrees apart. Coordinate exact locations with COTR. B. Reuse/ reinstall existing anchors. C. Flash watertight as specified. 8.0 COUNTERPOISE/ GRATING MATERIAL A. Remove and repair sections of existing grating (when decking is damaged, must be removed to replace damaged roof decking below) or remove existing and install new grating over the entire roof deck surface and install radial ground wires. Staple grating to deck. 4
B. The following materials are commonly used for grating: Copper Mesh, Galvanized welded wire, Galvanized expanded metal, Terne II and Terne coated S.S. 9.00 ROOFING MATERIAL The following are the most widely specified types of roofing system for these types of facilities. 1. PVC Single-ply roofing system- PVC membrane roofing system as manufactured by Sika Sarnafil. Equal roofing systems of other manufacturer s will be considered if they can be demonstrated to be an equal product with the same warranty as required. 1.1 Related Work: The work includes but is not necessarily limited to the installation of: 1. Wood blocking 2. Tapered and Flat Stock Polyisocyanurate Insulation 3. Attachment Metal fasteners and plates 4. low Rise urethane adhesive 5. PVC roof membrane 6. PVC roof membrane securement bars, plates and metal fasteners 7. PVC roof membrane flashings 8. PVC walkway pads 9. Fabricated galvanized metal and PVC coated metal flashings 10. Sealants and adhesives 1.2. Summary of Work: In order to provide a complete warrantable roof system, roofing contractor is to provide all labor, tools, equipment, and materials to complete the reroofing project. Such materials that are required, but are not necessarily limited to: 1. 72-mil minimum, PVC membrane with a polyester felt backing, 2. 72-mil minimum fiberglass reinforced membrane for certain flashing details, 3. Metal plates and screws for the attachment of the specified insulation to the decking. 4. Polyisocyanurate insulation, 5. Tapered polyisocyanurate insulation (if required based on Engineer and/or contractor inspection), 6. Walk way protection mat/pads around the fiberglass antenna cone perimeter, the monitor antenna perimeter, sideband antennas perimeter (Doppler VOR), from the ladder access point to the fiberglass antenna cone. 7. PVC coated clad metal perimeter edging or other edge termination as indicated in project drawings. 1.3 Material Compatibility: Provide roofing material that are compatible with one another under conditions of service and application required, and 5
demonstrated by roofing system manufacturer based on testing and field experience. 1.4 Roof Manufacturer s Warranty: Submit a written Warranty, without monetary limitation, with all available options, including flashing endorsement, manufacturer s roof insulation and roofing manufacturer s accessories, signed by roofing system manufacturer s agreeing to promptly repair leaks resulting from defects in material or workmanship for the following warranty period: 1. A minimum of 20-year Full Systems Warranty shall be issued up on completion of the roofing project. 2. The warranty shall guarantee the entire roof system and associated work against defective materials and workmanship of installation, with NO exclusions for ponding of water. 2. Firestone RubberGard Platinum single-ply membrane system: 90-mil elastomeric sheet roofing that is adhered to acceptable substrate with Firestone bonding adhesive. Equal roofing systems of other manufacturer s will be considered if they can be demonstrated to be an equal product with the same warranty as required. 2.1 Related Work: The work includes but is not necessarily limited to the installation of: 1. Substrate Preparation 2. Tapered and Flat Stock Insulation installation 3. Attachment Metal fasteners and plates 4. Wood nailers/fascia installation 5. Membrane installation 6. Flashing installation 7. Insulation fasteners 8. Roof walkway pad installation 2.2. Summary of Work: In order to provide a complete warrantable roof system, roofing contractor is to provide all labor, tools, equipment, and materials to complete the reroofing project. Such materials that are required, but are not necessarily limited to: 1. Wood-nailers for flanges and roof accessories and plywood 2. Manufacturers membrane materials A. Firestone RubberGard platinum single-ply membrane system: 90-mil elastomeric sheet roofing that is adhered to acceptable substrate with Firestone bonding adhesive B. Approved Equals 3. Elastometric sheet roofing and flashing membrane: 90 mil of uninterrupted thickness 6
A. Pipes, Round Supports Flash with Firestone Pre-Molded EPDM pipe flashings where practical. Flash using Form Flash or Penetration Pockets when pre-molded EPDM pipe Flashing is not practical. 4. Polyisocyanurate/ OSB roof insulation, 5. Tapered polyisocyanurate insulation (if required based on Engineer and/or contractor inspection) 6. Walk way protection mat around the fiberglass antenna cone perimeter, the monitor antenna perimeter, sideband antennas perimeter (Doppler VOR) from the ladder access point to the fiberglass antenna cone. A. EPDM Walkway pads, with EPDM tape adhesive strips laminated to the bottom 2.3 Material Compatibility: Provide roofing material that are compatible with one another under conditions of service and application required, and demonstrated by roofing system manufacturer based on testing and field experience. 2.4 Roof Manufacturer s Warranty: Submit a written Warranty, without monetary limitation, with all available options, including flashing endorsement, manufacturer s roof insulation and roofing manufacturer s accessories, signed by roofing system manufacturer s agreeing to promptly repair leaks resulting from defects in material or workmanship for the following warranty period: 1. A minimum of 30-year Full Systems Warranty shall be issued up on completion of the roofing project. 2. The warranty shall guarantee the entire roof system and associated work against defective materials and workmanship of installation, with NO exclusions for ponding of water. 3. Modified bitumen membrane roof- single-ply modified bitumen roof system from one of the following manufacturers, or an approved equal: Firestone, Owens-Corning, Siplast, Tamko, TREMCO, DERBIGUM, Mule Hide. 3.1 Related Work: The work includes but is not necessarily limited to the installation of: 1. Substrate Preparation 2. Tapered and Flat Stock Insulation installation 3. Attachment Metal fasteners and plates 4. Wood nailers/fascia installation 5. Membrane installation 6. Flashing installation 7. Insulation fasteners 8. Roof walkway pad installation 7
3.2 Material Compatibility: Provide roofing material that are compatible with one another under conditions of service and application required, and demonstrated by roofing system manufacturer based on testing and field experience. 3.3 Roof Manufacturer s Warranty: Submit a written Warranty, without monetary limitation, with all available options, including flashing endorsement, manufacturer s roof insulation and roofing manufacturer s accessories, sighed by roofing system manufacturer s agreeing to promptly repair leaks resulting from defects in material or workmanship for the following warranty period: SPECIAL REQUIREMENTS There may be roof projects in which the contractor will be required to replace the roof in conjunction with an upgrade by the FAA of the existing facility from a conventional VOR to a Doppler VOR (16 monitor antennas to 50 monitor antennas). Successful completion of both projects will require staged completion of the major work elements as defined below or as ordered by the engineer during construction. STAGE 1: Roofing Contractor: Remove the existing roofing/flashing, perimeter antennas/ mounts/bolts and antenna wiring/flex-conduit (on under-side of roof). Patch/repair holes from removed items, prep and paint the underside of the roof over hang, and install new roofing system with permanent roof edge flashing/metal and temporary flashing around the antenna cone. Supply 50 precut 28 x 28 (approximate) membrane/flashing patches to the FAA. STAGE 2: FAA: Remove temporary flashing around antenna cone and remove antenna cone for installation of new Doppler equipment. Cut 50 12 square holes in new membrane and install new Doppler monitor antennas. STAGE 3: Roofing Contractor: Install membrane/flashing patch material around each of the 50 new Doppler monitor antennas. Paint and reinstall fiberglass antenna cone on roof. STAGE 4: Roofing contractor: Install final flashing between new roof membrane and fiberglass antenna cone. Weld 50 membrane/flashing patches (Doppler VOR) to the new roof membrane. Coordinate/conduct roof system manufacturer inspection of completed roof system and supply manufacturers warranty for new roof system 8
Typical VOR Facilities & Details Doppler VOR Conventional VOR (Wood frame) Tin Can VOR (Conventional) 9
Copper Mesh Grating Flattened Expanded Metal Grating PVC walk pad and Cone base EPDM walk pad and Cone base 10
Typical underside of roof overhang area to be prep d and painted Typical Under roof deck repair at monitor antenna location. 11
Typical Modified bitumen roof and monitor antennas Insulation Grating PVC Membrane Typical VOR roof Section 12