Ga Rc 2601
Question:
In RC 2601, is RC-1 Channel used?
Answer:
As you can see from the description below, RC 2601 does NOT include resilient channel.
GA FILE NO. RC 2601 1 HOUR FIRE
Approx. Ceiling Weight: 5 psf
Fire Test: FM FC 172, 2-25-72, ITS, 8-6-98
GYPSUM WALLBOARD, WOOD JOISTS, ROOF COVERING
Base layer 5/8 in. type X gypsum wallboard applied at right angles to 2 x 10 wood joists 24 in. O.C. with 1 1/4 in. Type W or S drywall screws 24 in. O.C. Face layer 5/8 in. type X gypsum wallboard or gypsum veneer base applied at right angles to joists with 17/8 in. Type S drywall screws 12 in. O.C. at joints and intermediate joists and 1 1/2 in. Type G drywall screws 12 in. O.C. placed 2 in. back on either side of end joints. Joints offset 24 in. from base layer joints. Wood joists supporting 1/2 in plywood with exterior glue applied at right angles to joists with 8d nails. Appropriate roof covering. Ceiling provides one-hour fire resistance protection for wood framing, including trusses.
As far as hanging two layers of 5/8 in. gypsum with a single resilient channel, there are fire-rated assemblies that do have more than one layer of gypsum applied with resilient channel. See UL L556 for example.
For more information, see SBCA Research Report 1509-01: Fire Resistance Rated Truss Assemblies.