1. Floor Topping (optional, not shown): Gypsum
concrete, lightweight or normal concrete topping.
2. Floor Sheathing: Minimum 23/32 inch thick tongue-and-groove
wood sheathing (Exposure 1). Installed per code requirements with minimum
8d common nails.
3. Structural Members: Wood I-joists spaced a maximum
of 24 inches on center.
| |
Minimum I-joist flange depth: 1-5/16 inches |
Minimum I-joist flange area: 1.95 inches2 |
| |
Minimum I-joist web thickness: 3/8 inch |
Minimum I-joist depth: 9-1/2 inches |
| |
| See ASTM D 5055-07 for qualification requirements. |
4. Resilient Channelsb: Minimum
0.019 inch thick galvanized steel resilient channel attached perpendicular
to the bottom flange of the I-joists with one 1-1/4 inch drywall screw.
Channels spaced a maximum of 16 inches on center [24 inches on center
when I-joists are spaced a maximum of 16 inches on center].
5. Gypsum Wallboard: Two layers of minimum 1/2
inch Type X gypsum wallboard attached with the long dimension perpendicular
to the resilient channels as follows:
| |
5a. Wallboard Base Layer: Base layer of wallboard
attached to resilient channels using 1-1/4 inch Type S drywall screws
at 12 inches on center. |
| |
5b. Wallboard Face Layer: Face layer of wallboard
attached to resilient channels through base layer using 1-5/8 inch
Type S drywall screws spaced 12 inches on center. Edge joints of wallboard face
layer offset 24 inches from those of base layer. Additionally, wallboard face layer attached to base layer with 1-1/2 inch Type G drywall screws spaced 8 inches on center, placed 1-1/2 inches from face layer end joints. |
6. Finish System (not shown): Face layer joints covered with tape and coated with joint compound. Screw heads covered with joint compound.
| |
Fire Test conducted at National Research Council of Canada |
Report No: A-4440.1 |
June 24, 1997 |
|
STC and IIC Sound Ratings for Listed Assembly |
| Without Gypsum Concrete |
With Gypsum Concrete |
| Cushioned Vinyl |
Carpet & Pad |
Cushioned Vinyl |
Carpet & Pad |
| STC |
IIC |
STC |
IIC |
STC |
IIC |
STC |
IIC |
| - |
- |
54 |
68 |
- |
- |
58 c |
55 c |
| a This assembly may also be used in a fire-rated roof/ceiling application, but only when constructed exactly as described. |
| b Direct attachment of gypsum wallboard in lieu of
attachment to resilient channels is typically deemed acceptable. When gypsum
wallboard is directly attached to the I-joists, the wallboard should be
installed with long dimension perpendicular to the I-joists and sound ratings for WIJ-1.5 should be used. |
| c STC and IIC values estimated by David L. Adams Associates, Inc |
Copyright © 2002, 2007, 2009
AMERICAN WOOD COUNCIL
AMERICAN FOREST & PAPER ASSOCIATION, INC
January 2009
|
