USACE / NAVFAC / AFCESA / NASA UFGS-32 31 13 (January 2008) ---------------------------------- Preparing Activity: NASA Superseding UFGS-32 31 13.00 40 (October 2006) UFGS 32 31 00.00 20 (October 2006) UFGS 32 31 00.00 10 (October 2006) UNIFIED FACILITIES GUIDE SPECIFICATIONS References are in agreement with UMRL dated January 2009 SECTION 32 31 13 CHAIN LINK FENCES AND GATES 01/08 NOTE: This section covers steel fencing, including posts, fabric, gates, and miscellaneous accessories. Colored fabric and accessories may be used if required. Specifications must be revised to suit. Use Section 32 31 13.53 for HIGH-SECURITY CHAIN LINK FENCES AND GATES. Use Section 32 31 26 for WIRE FENCES AND GATES, formerly referred to as "Farm Style Fencing" within UFGS. Edit this guide specification for project specific requirements by adding, deleting, or revising text. For bracketed items, choose applicable item(s) or insert appropriate information. Remove information and requirements not required in respective project, whether or not brackets are present. This guide specification includes tailoring options for NAVFAC. Selection or deselection of a tailoring option (select view-tailoring options) will include or exclude that option in the section. Specific project editing is still required for the resulting section. Comments and suggestions on this guide specification are welcome and should be directed to the technical proponent of the specification. A listing of technical proponents, including their organization designation and telephone number, is on the Internet. Recommended changes to a UFGS should be submitted as a Criteria Change Request (CCR). PART 1 GENERAL 1.1 REFERENCES NOTE: This paragraph is used to list the publications cited in the text of the guide specification. The publications are referred to in the text by basic designation only and listed in this paragraph by organization, designation, date, and title. Use the Reference Wizard's Check Reference feature when you add a RID outside of the Section's Reference Article to automatically place the reference in the Reference Article. Also use the Reference Wizard's Check Reference feature to update the issue dates. References not used in the text will automatically be deleted from this section of the project specification when you choose to reconcile references in the publish print process. The publications listed below form a part of this specification to the extent referenced. The publications are referred to within the text by the basic designation only. ASTM INTERNATIONAL (ASTM)ASTM A 116(2005) Standard Specification for Metallic-Coated, Steel Woven Wire Fence FabricASTM A 153/A 153M(2005) Standard Specification for Zinc Coating (Hot-Dip) on Iron and Steel HardwareASTM A 702(1989; R 2006) Standard Specification for Steel Fence Posts and Assemblies, Hot WroughtASTM A 780(2001; R 2006) Standard Practice for Repair of Damaged and Uncoated Areas of Hot-Dip Galvanized CoatingsASTM A 90/A 90M(2007) Standard Test Method for Weight [Mass] of Coating on Iron and Steel Articles with Zinc or Zinc-Alloy CoatingsASTM B 117(2007a) Standing Practice for Operating Salt Spray (Fog) ApparatusASTM C 94/C 94M(2007) Standard Specification for Ready-Mixed ConcreteASTM F 1043(2008) Strength and Protective Coatings on Metal Industrial Chain-Link Fence FrameworkASTM F 1083(2008) Standard Specification for Pipe, Steel, Hot-Dipped Zinc Coated (Galvanized) Welded, for Fence StructuresASTM F 567(2007) Standard Practice for Installation of Chain Link FenceASTM F 626(2008) Standard Specification for Fence FittingsASTM F 883(2004) PadlocksASTM G 23(1996) Operating Light-Exposure Apparatus (Carbon-Arc Type) With and Without Water for Exposure of Nonmetallic MaterialsASTM G 26(1996) Operating Light-Exposure Apparatus (Xenon-Arc Type) With and Without Water for Exposure of Nonmetallic MaterialsASTM G 53(1996) Operating Light- and Water-Exposure Apparatus (Fluorescent UV-Condensation Type) for Exposure of Nonmetallic MaterialsU.S. GENERAL SERVICES ADMINISTRATION (GSA)FS RR-F-191(Rev K) Fencing, Wire and Post Metal (and Gates, Chain-Link Fence Fabric, and Accessories)FS RR-F-191/1(Rev D) Fencing, Wire and Post, Metal (Chain-Link Fence Fabric)FS RR-F-191/2(Rev D) Fencing, Wire and Post, Metal (Chain-Link Fence Gates)FS RR-F-191/3(Rev D) Fencing, Wire and Post, Metal (Chain-Link Fence Posts, Top Rails and Braces)FS RR-F-191/4(Rev D) Fencing, Wire and Post, Metal (Chain-Link Fence Accessories)1.2 SUBMITTALS NOTE: Review Submittal Description (SD) definitions in Section 01 33 00 SUBMITTAL PROCEDURES and edit the following list to reflect only the submittals required for the project. Submittals should be kept to the minimum required for adequate quality control. A “G” following a submittal item indicates that the submittal requires Government approval. Some submittals are already marked with a “G”. Only delete an existing “G” if the submittal item is not complex and can be reviewed through the Contractor’s Quality Control system. Only add a “G” if the submittal is sufficiently important or complex in context of the project. For submittals requiring Government approval on Army projects, a code of up to three characters within the submittal tags may be used following the "G" designation to indicate the approving authority. Codes for Army projects using the Resident Management System (RMS) are: "AE" for Architect-Engineer; "DO" for District Office (Engineering Division or other organization in the District Office); "AO" for Area Office; "RO" for Resident Office; and "PO" for Project Office. Codes following the "G" typically are not used for Navy, Air Force, and NASA projects. Choose the first bracketed item for Navy, Air Force and NASA projects, or choose the second bracketed item for Army projects. Government approval is required for submittals with a "G" designation; submittals not having a "G" designation are [for Contractor Quality Control approval.][for information only. When used, a designation following the "G" designation identifies the office that will review the submittal for the Government.] Submit the following in accordance with Section 01 33 00 SUBMITTAL PROCEDURES: _{SD-02 Shop Drawings} Submit _{Erection/Installation Drawings} for the following items in accordance with paragraph entitled, "Assembly and Installations Instructions," of this section. _{Fence Assembly Location of Gate, Corner, End, and Pull Posts Gate Assembly Gate Hardware and Accessories SD-03 Product Data} Submit Manufacturer's catalog data for the following items: _{Fence Assembly Gate Assembly Gate Hardware and Accessories SD-04 Samples} Contractor must submit the following samples described within this section: _{Fabric Posts Braces Line Posts Sleeves Top Rail [Bottom Rail] Tension Wire Stretcher Bars Gate Posts Gate Hardware and Accessories Padlocks Wire Ties SD-07 Certificates} Submit Certificates of compliance in accordance with the applicable reference standards and descriptions of this section for the following items: _{Zinc Coating PVC coating aluminum alloy coating Fabric Stretcher Bars Gate Hardware and Accessories Concrete SD-08 Manufacturer's Instructions} Submit Manufacturer's instructions for the following items: _{Fence Assembly Gate Assembly Hardware Assembly Accessories} 1.3 ASSEMBLY AND INSTALLATION INSTRUCTIONS Contractor must provide manufacturer's instructions that detail proper assembly and materials in the design for fence, gate, hardware and _accessories. Submit _{Erection/Installation drawings} along with manufacturer's catalog data for Complete _{fence assembly}, _{gate assembly}, _{hardware assembly} and _accessories. 1.4 DELIVERY, STORAGE, AND HANDLING Deliver materials to site in an undamaged condition. Store materials off the ground to provide protection against oxidation caused by ground contact. 1.5 QUALITY ASSURANCE 1.5.1 Required Report Data Submit reports of listing of chain-link fencing and accessories regarding weight in grams ounces for _{zinc coating} [, thickness of _{PVC coating}][, and chemical composition and thickness of _{aluminum alloy coating}]. PART 2 PRODUCTS 2.1 GENERAL Provide fencing materials that conform to the requirements of ASTM A 116, ASTM A 702, ASTM F 626, and as specified. 2.2 _{ZINC COATING} Ferrous-metal components and accessories, except as otherwise specified, must be hot-dip galvanized after fabrication. Provide zinc coating of weight not less than 550 gram per square meter 1.94 ounces per square foot, as determined from the average result of two specimens, when tested in accordance with ASTM A 90/A 90M. Provide zinc coating that conforms to the requirements of the following: Pipe: FS RR-F-191/3 Class 1 [Grade A in accordance with ASTM F 1083] [Grade B in accordance with ASTM F 1043 ]. Hardware and accessories: ASTM A 153/A 153M, Table 1 Surface (ASTM F 1043): External: Type B-B surface zinc with organic coating, 275 gram per square meter 0.97 ounce per square foot minimum thickness of acrylated polymer. Internal: Surface zinc coating of 275 gram per square meter 0.97 ounce per square foot minimum. Provide galvanizing repair material that is cold-applied zinc-rich coating conforming to ASTM A 780. 2.3 _FABRIC NOTE: Coordinate type of fabric with project requirements. The four types of fabric are not necessarily equivalent. Certain security applications may require use of steel fabric only. Standard selvage treatment for fabric 1.52 m 60 inches and less is knuckled at both selvages. Fabric with heavier zinc or aluminum coating or polyvinyl chloride (PVC) coatings may be useful in highly corrosive environments. NOTE: Choose core wire gage appropriate for the design. Gages will not be the same for all materials. Polyvinyl chloride (PVC) coating may be specified for other than security purposes when aesthetics are of prime importance and the additional cost is justified. There are different PVC-coated fabrics on the market. Some ways in which they may vary are: The methods of applying PVC coating, wall thickness of PVC coating, adhesion of PVC coating to wire, and cost. Take these factors into consideration when selecting a fence fabric for different environmental applications. PVC coating of fencing for certain security applications and fencing requiring grounding must be designed and specified very carefully. FS RR-F-191 and detailed specifications as referenced and other requirements as specified. FS RR-F-191/1; Type [I, zinc-coated steel, [_____] gage] [II, aluminum-coated steel, [_____] gage] [III, aluminum alloy, [_____] gage] [or] [IV, polyvinyl chloride (PVC) coated over zinc- or aluminum-coated steel, [_____]-gage core wire size]. Mesh size, 51 mm 2 inches. Provide selvage [knuckled at one selvage and twisted and barbed at the other] [twisted and barbed at both selvages] [knuckled at both selvages]. Height of fabric, as indicated. Fabric must consist of 3.8 millimeter No. 9-gage wires woven into a [25] [45] [50] millimeter [1-inch] [1-3/4-inch] [2-inch] diamond mesh, with dimensions of fabric and wire conforming to ASTM A 116, ASTM A 702 and ASTM F 626 , with 366 gram per square meter 1.29 ounces per square foot zinc galvanizing. Fence heights to 3658 millimeter 12 feet must have one-piece fabric widths. 2.4 TOP AND BOTTOM SELVAGES _Fabric with 51 millimeter 2 inch mesh and up to 1524 millimeter 60 inches high must be knuckled on both top and bottom selvages, over if 1524 millimeter 60 inches high, it must be twisted and barbed on the top selvage and knuckled on the bottom selvage. Knuckle top and bottom selvages for 45 millimeter and 25 millimeter 1-3/4-inch and 1-inch mesh fabric. 2.5 _POSTS [, TOP RAILS] [, BOTTOM RAILS] AND _BRACES NOTE: Use as many of the options as possible consistent with functional requirements. Allow Class 3, formed steel sections as an alternative if no other requirements prohibit their use on a particular job. Certain security applications using intrusion detection sensors, must use steel pipe framework only. For rails and braces, use minimum sizes specified in FS RR-F-191/3 for each class and grade unless members are to be oversized. NOTE: Steel pipe is available in two grades: A or B. Grade A is zinc-coated with 0.54 kg per square meter 1.8 ounces per square foot of zinc. Grade B consists of a zinc-coating with 0.27 kg per square meter 0.9 ounce per square foot, a chromate conversion coating, followed by a clear acrylic or polyester coating. The acrylic or polyester coatings used on Grade B pipe should not be confused with optional polyvinyl chloride (PVC) coatings available for framework. Grade A pipe which has the heavier zinc-coated interior may be desired in some coastal regions located in highly corrosive salt-laden environments to prevent rust caused by condensation inside the pipe. Grade A or Grade B pipe may be used in inland and desert areas, provided Grade B pipe meets the salt spray test. FS RR-F-191/3 line posts; Class [1, steel pipe, Grade [A] [or] [B]] [2, aluminum pipe] [3, formed steel sections] [4, steel H sections] or [5, aluminum H sections]. End, corner, and pull posts; Class [1, steel pipe, Grade [A] [or] [B]], [2, aluminum pipe], [6, steel square sections] [or 7, aluminum square sections]. Braces [and rails]; Class [1, steel pipe, Grade [A] [or] [B]] [2, aluminum pipe] or [3, formed steel sections], in [minimum sizes listed in FS RR-F-191/3 for each class and grade] [size [_____]]. [Provide PVC color coating, minimum thickness, 0.25 mm 0.10 inch.] [Steel pipe, Class 1, Grade B must meet the following performance criteria when subjected to salt spray testing in accordance with ASTM B 117: a. Exterior [_____] 1,000 hours with maximum 5 percent red rust. b. Interior [_____] 650 hours with maximum 5 percent red rust.] 2.5.1 Composite Posts NOTE: Provide as alternative to PVC coated fence posts, and use where corrosion is a problem. Since posts are non-conductive, fence grounding procedures need to be detailed where grounding of the fence is required. Produce resin reinforced posts from polyester or epoxy resin, reinforced with E-glass and filler material. Provide post that meet the ASTM F 1043 bending strength for heavy industrial fencing, and filled with 20 MPa 3,000 psi concrete. Protect posts from UV degradation by a veil of polyester cloth impregnated with resin and an acrylic based 1.46 mm 1.5 mil DFT coating system. The post must exhibit no structural failure (less than 10 percent loss of strength) as a result of exposure to moisture and UV lamps per ASTM G 23, ASTM G 26, and ASTM G 53, (3600 hours). Provide posts [green], [black], [brown] in color to match fabric. [Provide outside diameter as specified in FS RR-F-191/3 for round steel pipe.] 2.6 _{LINE POSTS} Minimum acceptable line posts must be as follows: Up to 1829 millimeter 6-feet high: Grade A: DN50 1.900 inch O.D. pipe weighing 4.05 kilogram per linear meter 2.72 pounds per linear foot . Grade B: DN60 2.375 inch O.D. pipe weighing 4.65 kilogram per linear meter 3.12 pounds per linear foot . Over 1829 millimeter 6-feet high: DN50 2.0 inch O.D. pipe weighing 5.44 kilogram per linear meter 3.65 pounds per linear foot. 2.7 END, CORNER, AND PULL POSTS Provide minimally acceptable end, corner, and pull posts as follows: Up to 1829 millimeter 6 feet high: Grade A: DN50 2.375 inch O.D. pipe weighing 5.44 kilogram per linear meter 3.65 pounds per linear foot . Grade B: DN60 2.375 inch O.D. pipe weighing 4.65 kilogram per linear meter 3.12 pounds per linear foot . Over 1829 millimeter 6 feet high: Grade A: DN70 2.875 inch O.D. pipe weighing 8.62 kilogram per linear meter 5.79 pounds per linear foot . Grade B: DN70 2.875 inch O.D. pipe weighing 6.91 kilogram per linear meter 4.64 pounds per linear foot . 2.8 _SLEEVES Provide sleeves for setting into concrete construction of the same material as post sections. Size must be 25 millimeter 1-inch greater than the diameter or dimension of the post. Weld flat plates to each sleeve base to provide anchorage and prevent intrusion of concrete. 2.9 _{TOP RAIL} Rails must be a minimum of DN40 1.660 inches O.D. pipe [Grade A weighing 3.38 kilogram per linear meter 2.27 pounds per linear foot.] [Grade B weighing 2.71 kilogram per linear meter 1.82 pounds per linear foot.] Provide expansion couplings 150 millimeter 6-inches long at each joint in top rails. [2.10 CENTER RAILS BETWEEN LINE POSTS NOTE: Center rails are not normally required for fencing less than 1829 millimeter 6 feet high. Edit as required. For fencing over 1829 millimeter 6-feet high, center rails must be DN40 1.660 inches O.D. pipe [Grade A weighing 3.38 kilogram per linear meter 2.27 pounds per linear foot] [Grade B weighing 2.71 kilogram per linear meter 1.82 pounds per linear foot.] ][2.11 [BOTTOM RAIL] [_{[Bottom Rail]} must conform to minimum sizes specified in FS RR-F-191/3 for each class and grade unless members are to be oversized.] ]2.12 POST-BRACE ASSEMBLY Bracing must consist of DN40 1.660 inches O.D. pipe [Grade A weighing 3.38 kilogram per linear meter 2.27 pounds per linear foot] [Grade B weighing 2.71 kilogram per linear meter 1.82 pounds per linear foot] and 10 millimeter 3/8 inch adjustable truss rods and turnbuckles. 2.13 _{TENSION WIRE} Wire must be galvanized, 3.7 millimeter No. 7-gage, coiled spring wire, provided at the bottom of the fabric only. Provide _{Zinc Coating} that weighs not less than 490 gram per square meter 1.6 ounces per square foot. 2.14 _{STRETCHER BARS} Provide bars that have one-piece lengths equal to the full height of the fabric with a minimum cross section of 5 by 20 millimeter 3/16 by 3/4 inch, in accordance with ASTM A 116, ASTM A 702 and ASTM F 626. 2.15 POST TOPS Provide tops that are steel, wrought iron, or malleable iron designed as a weathertight closure cap. Provide one cap for each post, unless equal protection is provided by a combination post-cap and barbed-wire supporting arm. Caps must have an opening to permit through passage of the top rail. 2.16 STRETCHER BAR BANDS Provide bar bands for securing stretcher bars to posts that are steel, wrought iron, or malleable iron spaced not over 381 millimeter 15 inches on center. Bands may also be used in conjunction with special fittings for securing rails to posts. Provide bands with projecting edges chamfered or eased. 2.17 _{GATE POSTS} Provide a gate post for supporting each gate leaf as follows: [Up to 1829 millimeter 6-feet wide: DN75 2.875 inch O.D. pipe [Grade A weighing 8.62 kilogram per linear meter 5.79 pounds per linear foot .] [Grade B weighing 6.91 kilogram per linear meter 4.64 pounds per linear foot.]] [Over 1829 millimeter 6 feet wide and up to 3962 millimeter 13 feet wide: DN75 2.875 inch O.D. pipe [Grade A weighing 8.62 kilogram per linear meter 5.79 pounds per linear foot .] [Grade B weighing 6.91 kilogram per linear meter 4.64 pounds per linear foot.]] [Over 3962 millimeter 13-feet and up to 5486 millimeter 18-feet wide: Provide DN150 6.625 inch O.D. pipe weighing 28.26 kilogram per linear meter 18.97 pounds per linear foot.] [Over 5486 millimeter 18-feet wide: Provide DN220 8.625 inch O.D. pipe weighing 36.79 kilogram per linear meter 24.70 pounds per linear foot .] 2.18 GATES NOTE: The gate frames and intermediate braces indicated are adequate for gate sizes less than or equal to 2.4 m 8 feet high and 4.3 m 14 feet wide. Gate configurations larger than 2.4 m 8 feet high and4.3 m 14 feet wide shall require special design consideration. FS RR-F-191/2; Type [I, single swing] [II, double swing] [III, single cantilever sliding, wheel sliding gate] [IV, double cantilever sliding] [V, single overhead sliding] [VI, double overhead sliding] [VII, vertical lift] [VIII, special]. Shape and size of gate frame, [as indicated] [_____]. Framing and bracing members, [round][square] of [steel][aluminum] alloy. [Steel member finish, [zinc-coated] [or] [PVC-coated over zinc- or aluminum-coated steel].] Gate frames and braces of minimum sizes listed in FS RR-F-191/3 for each Class and Grade except that steel pipe frames must be48 mm 1.90 inches od, 3 mm 0.120 inches minimum wall thickness and aluminum pipe frames and intermediate braces must be 47.5 mm 1.869 inches od, 1.4 kg per meter 0.940 lb/ft of length. Gate fabric, as specified for fencing fabric. Coating for steel latches, stops, hinges, keepers, and accessories, [galvanized] [PVC, minimum thickness of 0.25 mm 0.010 inch.] Gate latches, [fork] [plunger bar] type. [Special gate frames, [as indicated] [_____].] [Gate leaves more than 2.4 m 8 feet wide must have intermediate members as necessary to provide rigid construction, free from sag or twist.] [Gate leaves less than 2.4 m 8 feet wide must have truss rods or intermediate braces.] Attach gate fabric to gate frame in accordance with manufacturer's standards, except that welding is not permitted. Arrange padlocking latches to be accessible from both sides of gate, regardless of latching arrangement. [For gate leaves up to 1829 millimeter 6-feet high or 1829 millimeter 6-feet wide, perimeter gate frames must be DN32 1.66 inch O.D. pipe [Grade A weighing 3.38 kilogram per linear meter 2.27 pounds per linear foot.] [Grade B weighing 2.71 kilogram per linear meter 1.82 pounds per linear foot.]] [For gate leaves over 1829 millimeter 6 feet high or 1829 millimeter 6 feet wide, perimeter gate frames must be DN40 1.90 inch O.D. pipe [Grade A weighing 4.05 kilogram per linear meter 2.72 pounds per linear foot.] [Grade B weighing 3.40 kilogram per linear meter 2.28 pounds per linear foot.]] Provide gate frame assembly that is welded or assembled with special malleable or pressed-steel fittings and rivets to provide rigid connections. Install fabric with stretcher bars at vertical edges; stretcher bars may also be used at top and bottom edges. Attach stretcher bars and fabric to gate frames on all sides at intervals not exceeding 381 millimeter. 15 inches. Attach hardware with rivets or by other means which provides equal security against breakage or removal. Diagonal cross-bracing, consisting of 10 millimeter 3/8-inch diameter adjustable-length truss rods on welded gate frames, must be provided where necessary to obtain frame rigidity without sag or twist. Provide nonwelded gate frames with diagonal bracing. 2.19 _{GATE HARDWARE AND ACCESSORIES} Provide gate hardware and accessories that conforms to ASTM A 116, ASTM A 702, ASTM F 626, and be as specified: Provide [malleable iron] [forged steel] [pressed steel] hinges to suit gate size, non-lift-off type, offset to permit 180-degree opening. Provide latch that permits operation from either side of the gate, with a padlock eye provided as an integral part of the latch. Provide stops and holders of malleable iron for vehicular gates. Provide stops that automatically engage the gate and hold it in the open position until manually released. NOTE: Delete the following paragraph when double gates are not required. [Provide double gates with a cane bolt and ground-set keeper, with latch or locking device and padlock eye designed as an integral part.] NOTE: Delete the following paragraph if manual sliding gates are not required. [Provide manufacturer's standard heavy-duty track ball bearing hanger sheaves, overhead framing and supports, guides, stays, bracing, and accessories as required for easy operation of manual sliding gates.] 2.20 MISCELLANEOUS HARDWARE Provide miscellaneous hot-dip galvanized hardware as required. 2.21 _{WIRE TIES} Wires for tying fabric to line posts must be 1.6 millimeter 16-gage galvanized steel wire spaced 300 millimeter 12 inches on center. For tying fabric to rails and braces, wire ties must be spaced 600 millimeter 24 inches on center. For tying fabric to tension wire, 2.7 millimeter 0.105-inch hog rings must be spaced 600 millimeter 24 inches on center. Manufacturer's standard procedure will be accepted if of equal strength and durability. NOTE: Polyvinyl chloride (PVC) coated ties shall be specified when PVC-coated fence fabric is required. FS RR-F-191/4. Provide wire ties constructed of the same material as the fencing fabric. [Provide accessories with polyvinyl (PVC) coatings similar to that specified for chain-link fabric or framework.] 2.22 _CONCRETE Provide concrete conforming to ASTM C 94/C 94M. Concrete mix must obtain a minimum 28-day compressive strength of 20685 kilopascal 3,000 psi. 2.23 GROUT Provide grout of proportions one part portland cement to three parts clean, well-graded sand and a minimum amount of water to produce a workable mix. 2.24 _PADLOCKS NOTE: Consult station regarding padlocks. Most stations will provide padlocks. If Contractor furnished padlocks are required for certain security applications, a padlock conforming to an appropriate Military or Agency Specification may need to be specified. See referenced specification for types, grades, and options available. Provide padlocks conforming to ASTM F 883, with chain. PART 3 EXECUTION Completed installation must conform to ASTM F 567. 3.1 GENERAL Final grading and established elevations must be complete prior to commencing fence installation. 3.2 EXCAVATION Excavations for post footings must be [drilled holes] in virgin or compacted soil, of minimum sizes as indicated. Space footings for line posts 3048 millimeter 10 feet on center maximum and at closer intervals when indicated. Bottoms of the holes must be approximately 75 millimeter 3-inches below the bottoms of the posts. Set bottom of each post not less than 915 millimeter 36-inches below finished grade when in firm, undisturbed soil. Set posts deeper, as required, in soft and problem soils and for heavy, lateral loads. Soil from excavations must be [spread uniformly adjacent to the fence line or on areas of Government property, as directed.] [removed from Government property.] When solid rock is encountered near the surface, the Contractor must drill into the rock at least 305 millimeter 12 inches for line posts and at least 457 millimeter 18 inches for end, pull, corner, and gate posts. Drill holes at least 25.4 millimeter 1 inch greater in diameter than the largest dimension of the placed post. If solid rock is below the soil overburden, Contractor must drill to the full depth required except that penetration into rock need not exceed the minimum depths specified above. 3.3 SETTING POSTS Remove loose and foreign materials from holes and the soil moistened prior to placing concrete. Provide tops of footings that are trowel finished and sloped or domed to shed water away from posts. Set hold-open devices, sleeves, and other accessories in concrete. Keep exposed concrete moist for at least 7 calendar days after placement or cured with a membrane curing material, as approved. [Posts set into sleeved holes in concrete must be grouted in with an approved grouting material.] [Posts set in concrete construction must be set vertically, with tops aligned and held in position until concrete has set.] 3.3.1 Earth and Bedrock NOTE: Alternate drive anchor method may be specified as an option where evidence indicates that optional method under similar ground conditions has satisfactory and proven performance record. Provide concrete bases of dimensions indicated [except in bedrock]. Compact concrete to eliminate voids, and finish to a dome shape. [In bedrock, set posts with a minimum of 25.4 mm 1 inch of grout around each post. Work grout into hole to eliminate voids, and finish to a dome shape.] [3.3.2 Concrete Slabs and Walls NOTE: Use the following paragraph where required by the design, otherwise delete. Sleeve joints for non-removable fence sections are usually filled with lead or nonshrink grout. Removable fence sections may be useful as an economical means for providing access to equipment. Sleeve joints in removable fence sections may be a tight sliding type, or where moisture entry could be a problem, filled with pipe sulphur jointing compound. Set posts into zinc-coated sleeves, set in concrete slab or wall, to a minimum depth of 305 mm 12 inches. Fill sleeve joint with lead, nonshrink grout, or other approved material. Set posts for support of removable fence sections into sleeves that provide a tight sliding joint and hold posts aligned and plumb without use of lead or setting material. ]3.3.3 Bracing NOTE: Use a single diagonal truss rod for fences less than 3.7 m 12 feet high. Use two diagonal truss rods on fences 3.7 m 12 feet and higher. Brace gate, corner, end, and pull posts to nearest post with a horizontal brace used as a compression member, placed at least 305 mm 12 inches below top of fence, and [a diagonal truss rod and truss tightener used as a tension member] [two diagonal truss rods and truss tighteners used as tension members]. 3.4 CONCRETE STRENGTH Provide _Concrete that has attained at least 75 percent of its minimum 28-day compressive strength, but in no case sooner than 7 calendar days after placement, before rails, tension wire, or fabric are installed. Fabric and wires must not be stretched or gates hung until the concrete has attained its full design strength. NOTE: Delete the following paragraph if the referenced section is not included. Samples and test concrete must be taken to determine strength as specified. 3.5 TOP RAILS Provide top rails that run continuously through post caps or extension arms, bending to radius for curved runs. Provide expansion couplings as recommended by the fencing manufacturer. [3.6 CENTER RAILS Center rails must be one piece between posts set flush with posts on the fabric side, using special offset fittings where necessary. ]3.7 BRACE ASSEMBLY Contractor must provide bracing assemblies at end and gate posts and at both sides of corner and pull posts, with the horizontal brace located at midheight of the fabric. Install brace assemblies so posts are plumb when the diagonal rod is under proper tension. Provide two complete brace assemblies at corner and pull posts where required for stiffness and as indicated. 3.8 TENSION WIRE INSTALLATION Install tension wire by weaving them through the fabric and tying them to each post with not less than 3.9 millimeter 7-gage galvanized wire or by securing the wire to the fabric with 3.5 millimeter 10-gage ties or clips spaced 610 millimeter 24 inches on center. 3.9 FABRIC INSTALLATION Provide _Fabric in single lengths between stretch bars with bottom barbs placed approximately 38 millimeter 1-1/2-inches above the ground line. Pull fabric taut and tied to posts, rails, and tension wire with wire ties and bands. Install fabric on the security side of fence, unless otherwise directed. Fabric must remain under tension after the pulling force is released. 3.10 STRETCHER BAR INSTALLATION Thread stretcher bars through or clamped to fabric 102 millimeter 4 inches on center and secured to posts with metal bands spaced 381 millimeter 15 inches on center. 3.11 GATE INSTALLATION Install gates plumb, level, and secure, with full opening without interference. Install ground set items in concrete for anchorage as recommended by the fence manufacturer. Adjust hardware for smooth operation and lubricated where necessary. 3.12 TIE WIRES Provide tie wires that are U-shaped to the pipe diameters to which attached. Twist ends of tie wires not less than two full turns and bent so as not to present a hazard. 3.13 FASTENERS Install nuts for tension bands and hardware on the side of the fence opposite the fabric side. Peen ends of bolts to prevent removal of nuts. 3.14 ZINC-COATING REPAIR Clean and repair galvanized surfaces damaged by welding or abrasion, and cut ends of fabric, or other cut sections with specified galvanizing repair material applied in strict conformance with the manufacturer's printed instructions. 3.15 TOLERANCES Provide posts that are straight and plumb within a vertical tolerance of 6.35 millimeter 1/4 inch after the fabric has been stretched. Provide fencing and gates that are true to line with no more than 12.7 millimeter 1/2 inch deviation from the established centerline between line posts. Repair defects as directed. 3.16 SITE PREPARATION 3.16.1 Clearing and Grading Clear fence line of trees, brush, and other obstacles to install fencing. Establish a graded, compacted fence line prior to fencing installation. 3.17 FENCE INSTALLATION NOTE: Certain security applications require conformance to an applicable OPNAVINST. Use bracketed sentences as required by the applicable OPNAVINST. Install fence on prepared surfaces to line and grade indicated. [Secure fastening and hinge hardware in place to fence framework by peening or welding. Allow for proper operation of components. Coat peened or welded areas with a repair coating matching original coating.] Install fence in accordance with fence manufacturer's written installation instructions except as modified herein. 3.17.1 Post Spacing Provide line posts spaced equidistantly apart, not exceeding 3.048 m 10 feeton center. Provide gate posts spaced as necessary for size of gate openings. Do not exceed 152.4 m 500 feet on straight runs between braced posts. Provide corner or pull posts, with bracing in both directions, for changes in direction of 0.26 rad 15 degrees or more, or for abrupt changes in grade. Provide drawings showing _{location of gate, corner, end, and pull posts} . 3.17.2 Top and Bottom _{Tension Wire} NOTE: Coordinate with requirements for top and bottom rails. Bottom tension wire is desirable to maintain fence alignment and must be retained except for designs requiring bottom rail. Install [top] [and] [bottom] tension wires before installing chain-link fabric, and pull wires taut. Place top and bottom tension wires within 203 mm 8 inches of respective fabric line. 3.18 ACCESSORIES INSTALLATION 3.18.1 Post Caps NOTE: Coordinate with requirements for top rails or supporting arms. [Design post caps to accommodate top rail.] Install post caps as recommended by the manufacturer. 3.18.2 Padlocks Provide padlocks for gate openings and provide chains that are securely attached to gate or gate posts. Provide padlocks keyed alike, and provide two keys for each padlock. [3.19 GROUNDING NOTE: Delete this paragraph if grounding is not required. If grounding is required and lightning protection is not part of project design, the requirements in the second set of brackets will be used in lieu of those in the first set of brackets. Provide fence grounding details when composite type posts are specified where grounding of the fence is required. Grounding requirements may be indicated on the drawings or included in this section. Specify polyvinyl chloride coated fencing with care when grounding is a project requirement. Ground fencing as [indicated on drawings][and specified]. [Fences crossed by overhead powerlines in excess of 600 volts must be grounded. Electrical equipment attached to the fence must be grounded.][ Ground fences on each side of all gates, at each corner, at the closest approach to each building located within 15 m 50 feet of the fence, and where the fence alignment changes more than 15 degrees. Grounding locations must not exceed 198 m 650 feet. Bond each gate panel with a flexible bond strap to its gate post. Ground fences crossed by powerlines of 600 volts or more at or near the point of crossing and at distances not exceeding 45 m 150 feet on each side of crossing. Ground conductor must consist of No. 8 AWG solid copper wire. Grounding electrodes must be 19 mm 3/4 inch by 3.05 m 10 foot long copper-clad steel rod. Drive electrodes into the earth so that the top of the electrode is at least 152 mm 6 inches below the grade. Where driving is impracticable, electrodes must be buried a minimum of 305 mm 12 inches deep and radially from the fence. The top of the electrode must be not less than 610 mm 2 feet or more than 2.4 m 8 feet from the fence. Clamp ground conductor to the fence and electrodes with bronze grounding clamps to create electrical continuity between fence posts, fence fabric, and ground rods. Total resistance of the fence to ground must not be greater than 25 ohms.] ][3.20 SECURITY NOTE: Delete this paragraph if new fencing does not involve relocation or replacement of existing security fencing. Depending on nature of fence work, paragraph may need further elaboration regarding necessary construction to maintain perimeter. Install new security fencing, remove existing security fencing, and perform related work to provide continuous security for facility. Schedule and fully coordinate work with Contracting Officer and cognizant Security Officer. ]3.21 CLEANUP Remove waste fencing materials and other debris from the work site.