PART 1: GENERAL

1.1 Scope of Work

The contractor shall provide all labor, materials, equipment and incidentals as shown and specified and are required to furnish and install grating, stair treads and supports.

1.2 Quality Assurance

A . Comply with applicable provisions and recommendations of the ANSI/NAAMM MBG 532 for Heavy Duty Metal Bar Grating Manual.

B . The steel used in the Bearing Bars shall be of rectangular section and conform to ASTM A36 Hot Rolled Carbon Steel Bars. The Cross Bars shall be of ASTM A510 Carbon Steel Rods and Course Round Wire.

C. No substitution of materials will be accepted unless they are submitted for review and the Architect/Engineer approves their use.

1.3 Submittals

1. The contractor shall submit to the owner or its representative, for approval, shop drawings for fabrication and erection of the work. Included shall be plans, elevations, sections and details of the work.
2. The contractor shall submit the manufacturer's specifications, load tables, anchor details and standard installation details.
3. The contractor may be required to take field dimensions to verify “as built” conditions to ensure proper fit of grating.

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PART 2: PRODUCT

2.1 General

A. Grating shall be Amico Standard Welded Type “HD” 19-H-4 resistance welded grating as

manufactured by Alabama Metal Industries Corp. or approved equal.

B. Bearing bars: Rectangular steel bars of an appropriate depth and thickness for the required load, on 1 3/16” centers. Other available centers are; (15/16”; 1 3/8”; 1 7/8”; 2 3/8”; and) which may be selected at the discretion of the Architect/Engineer.

C. Cross Bars: Twisted wire rod, at 4” on center, resistance welded to the bearing bars and at right angles to them. Other available center is 2” as may be selected by the Architect/Engineer.

D. Surface: The bearing bars shall have a smooth top surface unless the Architect/Engineer determines the need for a serrated surface.

E. Loading: The uniform load shall be designated by the Architect/Engineer, the deflection shall not exceed ¼ inch over the required span.

F. Finish: Manufacturers standard shop coat black or Galvanized as required by Architect/Engineer

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PART 3: EXECUTION

3.1 Shop Fabrication

A. All required cutting, fitting and welding shall be performed in the manufacturers shop

in accordance with the approved shop drawings and shall be in compliance with the NAAMM Heavy Duty Metal Bar Grating Manual tolerances and welding standards.

B. All cutouts to clear obstructions shall have a recommended clearance of 1 inch. When banding and toe plates are required they shall be welded to the grating in accordance with NAAMM standards.

C. The finish coating, paint or galvanizing shall be applied after all of the required fabrication is complete.

3.2 Installation

A. The grating shall be received at the job site by the contractor, unloaded and protected from damage prior to the requirement for it to be installed.

B. The installing contractor shall prepare the site for installation, determining that deviations from the approved drawings are corrected prior to grating placement.

C. Grating shall be installed in accordance with the approved shop drawings and the installation clearances called for in the NAAMM Metal Bar Grating Manual including the use of the prescribed anchor system.