458Ornamental Fencing on Structures

458.01 Description

Fabricate, furnish, and erect ornamental fences on bridges and retaining walls.

458.02 Materials

Apply these requirements for fences and anti-climb shields.

458.02.01 Base Plate. Steel conforming to A 709, grade 50. Ensure that the ornamental fence

manufacturer is aware of the actual grade at the location of each fence post so that the post will be plumb, and the base plate will match the grade. The fabricator shall have the option of attaching the base plate to the bottom of the post after the post has been cut off/ground to the appropriate angle or using thicker base plates and beveling the bottoms to match the grade. Assemble base plates and posts prior to the application of the protective coatings.

458.02.02 Post and Pickets. Hot rolled steel conforming to A 787, G 90. The minimum tensile

strength shall be 50 000 psi.

458.02.03 Longitudinal Rails. Rolled “U” channels conforming to A 653, G 90, 1-3/8 in. wide by

1-1/2 in. deep with a 0.120 in. minimum wall thickness, pre-punched to receive pickets and rivets.

458.02.04 Rail Attachment Brackets. Die cast zinc conforming to B 86, 83Z 33521. Provide a ball

and socket design capable of swiveling 30 degrees up and down and right and left. Fully encapsulate the rail end in an aesthetically pleasing manner, as determined by the Engineer.

458.02.05 Rings. Cast aluminum conforming to B 85 or B 686, when specified. Fit rings between

pickets and longitudinal rails as shown on the Plans.

458.02.06 Caps. Provide watertight caps per the design shown on the Plans.

458.02.07 Protective Coatings. Galvanize undercoat all structural steel and gray iron casting

ornamental fence members both inside and outside as specified in Section 465. All die cast zinc members and galvanized members shall be given the four-stage wash pretreatment process outlined below prior to the application of the polyester finish coat. The process and materials used shall conform to the manufacturer’s specifications and recommendations but shall be approved by the Office of Materials Technology (OMT) before commencing the process.

458.02.08 Fasteners. Use 1/4 in. industrial drive rivets to attach pickets, finials, rings, rails, and post

attachments. Use 1/4 in. bolts to attach rail brackets to posts.

458.02.09 Anchor studs or bolts. Hot finished and annealed stainless steel conforming to A 276,

Type 430, or Type 304 with and ultimate strength of 70 000 psi and 20percent minimum elongation. Threads may be rolled or cut.

458.03 Construction

Prior to the start of fabrication, submit shop drawings that include elevations and slopes of the barrier at each post location and the selected method to make the post plumb. Attach all fence posts to the top of the concrete parapets or retaining walls by the means of cast in place anchor studs or bolts and ensure that all posts are plumb with tops properly aligned. Whenever the fence is attached to an existing structure (structure that existed prior to the Contract), the proposed anchorage methods shall be approved by the Office of Structures prior to beginning work. Regardless of the method proposed, locate the existing reinforcement near the post locations with non-destructive methods (i.e. pacometer, etc.) and include these measured locations in anchorage proposal. 458 — ORNAMENTAL FENCING ON STRUCTURES 2026 STANDARD SPECIFICATIONS FOR CONSTRUCTION AND MATERIALS Set all posts and pickets plumb. Set all longitudinal rails parallel to the top of the parapet or wall. If the rails are set to an angle more than 10 degrees off level, the contractor has the option to omit the rings. Use rivets for picket, finial, ring, rail, bracket, and post attachments except that rails for anti-climb shields shall be welded to posts. Attach each picket to each longitudinal rail with rivets. Use brackets to attach the rails to the posts except for anti-climb shields. Securely attach post caps to all posts per the manufacturer’s specifications and as approved by the Engineer. Install fence and accessories in accordance with the Contract Documents and in a workmanlike manner. Repair welds or replace elements from any defective items uncovered by the inspection at no additional cost to the Administration.

458.04 Measurement and Payment

The payment will be full compensation for all materials, labor, equipment, tools, and incidentals necessary to complete the work.

458.04.01 Ornamental fence will not be measured but will be paid for at the Contract lump sum price

for the pertinent Ornamental Fencing item.

458.04.02 Anti-climb shields will be measured and paid for at the Contract unit price per each for the

pertinent Ornamental Anti-Climb Shield item.