Section R102 Modifications to ASTM C 635 — Standard Specification for the Manufacture, Performance, and Testing of Metal Suspension Systems for Acoustical Tile and Lay-In Panel Ceilings

Delete Figure 1 and replace as follows:

Modify section 3.1 as follows:

3.1.1.4 carrying channel — The term "carrying channel" shall mean the three sided or "[" shaped-metal sections that support the entire structural grid network (Figure 1A, 1B, and 1C). The carrying channels are suspended by hangers from the existing structure and main runners are then attached to the channels.

3.1.1.6 cross runner — The term "cross runner" shall mean the secondary or cross beams of a mechanical ceiling suspension (Figure 1A). The cross runners normally support only the acoustical tile. In some forms of suspension systems, the cross runners also provide support for other cross runners.

3.1.1.7 hanger — The term "hanger" shall mean the member employed to suspend the acoustical ceiling from the existing structure (wood joists, steel bar joists, steel beams, concrete slabs, etc.) (Figure 1A, 1B, and 1C).

3.1.1.10 main runner — The term "main runner" shall mean the primary or main beams of the type of ceiling suspension system in Figure 1A and Figure 1B. The main runners provide direct support for cross runners, and they may support lighting fixtures and air diffusers. In addition, the acoustical tile may also be directly supported by the main runners. The main runners are installed perpendicular to the carrying channels and are supported by specially designed sheet metal or wire clips attached to the carrying channels (Figure 1A, 1B).

Add section 4.5 as follows:

4.5 Splines shall not be considered as providing nor shall be used for providing structural support for the ceiling material.