How to Install Single-Leg Resilient Channel (RC)

Details

This is a decades-old question, that has a simple answer: the narrow leg that is attached to the stud (also called the “mounting flange”) goes down, and the wider leg that is attached to the sheathing goes up. The one exception is at the very bottom row of RC, closest to the bottom track, can be installed with the wide leg down and the narrow leg up. RC is always installed horizontally, and the narrow flange always goes to the stud or framing member, with the wider flange providing a surface for sheathing attachment.

This is a decades-old question, that has a simple answer: the narrow leg that is attached to the stud (also called the “mounting flange”) goes down, and the wider leg that is attached to the sheathing goes up (see detail).  The one exception is at the very bottom row of RC, closest to the bottom track, can be installed with the wide leg down and the narrow leg up.  RC is always installed horizontally, and the narrow flange always goes to the stud or framing member, with the wider flange providing a surface for sheathing attachment.

This answer applies no matter what the framing is (wood or steel) and no matter what the framing spacing is.  There are several reasons for this: reasons that primarily have to do with fire and acoustic issues.

Resilient channel was initially developed as a spacer in walls: where a transition needed to be made from single-layer ½-inch gypsum to double layer gypsum.  The discovery that the channel provided better acoustical values was a welcome surprise to the makers of RC, and since then, manufacturers have developed various configurations of RC to maintain and improve acoustical performance.  A few years ago, installation of RC was added to ASTM C754, which includes the following provisions:

  • Mounting flange (1/2” wide) goes down, face flange (1-1/4” wide) goes up. Exception: first row closest to the floor may be inverted.
  • The first (lowest) row of resilient channel shall be not more than 2” off the floor (as measured from the floor to the center of the face of the resilient channel)
  • The highest row of resilient channel shall be not more than 6” from the ceiling (as measured from the ceiling to the center of the face of the resilient channel).
  • Holes or slots in the web (sloped face) of the resilient channel should be centered over the supporting framing members.
  • Pre-punched holes in the narrow flange should be used for the screws attaching the RC to the studs.
  • Gypsum panel products shall be attached to the resilient furring channel using screws and ensuring that the screw does not touch the studs.

Fastening to framing

  • For steel framing, use is a type S pan-head screw, with a 3/8” minimum length.
  • For wood framing, use type-S or type-W screws (not nails) with 1-1/4” length.  NOTE: Be aware that long screws in wood framing can loosen when wood dries out and shrinks.  Make sure to use only 1-1/4” or 1-1/2” long fasteners in wood – or better yet, use steel framing!

Splicing resilient channel – either method is acceptable:

  • Splicing method 1: “nesting” the ends of the resilient furring channel members (lapping one end of the RC over the other end of the next RC) directly over the framing member and screwing through the mounting flange into the framing members.
  • Splicing method 2: Butting adjacent RC, with a gap of not less than 1/16 inch centered over the flange of the framing member. Each channel should be individually attached through the mounting flange to the framing member with the appropriate fastener (as specified above.)

In addition to the installation requirements of ASTM C754, RC is included in several fire-rated assemblies.  If the wall you are building must comply with a specific Underwriters Laboratory (UL) or Gypsum Association (GA) or other design, consult the specific design requirements for fastening.  And remember: if any of the screws attaching the wallboard or anything attached to the wall goes through the RC and into the stud, it will “short circuit” the acoustical isolation of the resilient channel, and lead to worse-than-designed acoustical performance.

 

About Super Stud Building Products

Since 1973, Super Stud Building Products, Inc., with its roots in the New York Tri-State area, has been a proud manufacturer of the building industry’s most diverse offerings of steel framing components and accessories for use in the construction of commercial, institutional and residential structures. With manufacturing plants in Edison, New Jersey and Hattiesburg, Mississippi, Super Stud is a multi-regional steel framing and accessories manufacturer committed to quality products, unmatched service, competitive pricing and timely deliveries across the entire East Coast and beyond. Super Stud plays an active role in the steel framing industry, participating in the American Iron and Steel Institute (AISI), the Association of Walls and Ceilings International (AWCI), ASTM International and the Steel Framing Alliance (SFA). To learn more, visit  buysuperstud.com.