USG Exterior Ceiling Applications Systems Guide - Manual (Page 40)

39 USG Exterior Ceiling Applications
USG Drywall Suspension System
Test Record UL526F
Class 90 Uplift
System Components
Main Runners DGL26 or DGLW26
Cross Tees DGL224 or DGLW224
Perimeter Molding DGWM24 angle mold or DGCM27 channel mold.
When angle mold is used, main runners and cross tees attached to molding with 1/29 type S screws.
Plywood – 4 ft wide by 8 ft long by nom 3/8 in. thick (11/32 in.), B-C Group 1 exterior grade.
– Installed with long dimension perpendicular to main runner and centered along cross tees with end joints
centered along main runners.
– Plywood fastened to cross tees and main runners with 1-1/4 in. long steel screws spaced 8 in. o.c.
– End joints of adjacent plywood sheets staggered not less than 2 ft o.c. Plywood sheet screws attached
to lower leg of wall channel with screws spaced 12 in. o.c.
Gypsum Panels – 5/8 in. thick, 4 ft wide, installed with long dimension parallel with main runners with end joints centered
along cross tees and with side joints centered along main runners.
– Wallboard fastened to each cross tee and main runner through plywood with 1-5/8 in. long no. 8 bugle head
steel screws spaced 8 in. o.c. One screw located at the midspan of the cross tee, with screws spaced
8 in. o.c. from each side of the cross tee midspan with screws located 1-1/2 in. from each gypsum board
side joint. At butt ends joints of adjacent wallboard staggered 48 in.
– Gypsum board fastened to cross tees with 14 wallboard screws, seven per each end of wallboard.
– Wallboard sheets screw attached to lower leg of wall channel with wallboard screws spaced 12 in. o.c.
Type Max Unbraced Length (in)
Compression Posts 3/49 x 1/29 x 0.0599 channel 28
3/49 x 1/29 x 0.0599 channel (Back-to-back) 46
1-1/29 x 7/329 x 0.0599 channel 31
1-1/29 x 7/329 x 0.0599 channel (Back-to-back) 41
3/49 EMT conduit, 0.049” wall thickness 59
1-5/89 25 gauge steel studs, 0.01799 min 61
1-5/89 25 gauge steel studs, 0.01799 min (Back-to-back) 76
– Back to back types shall be connected with stitch welds at 129 OC or with 1/49 dia bolts at 129 OC,
first connection within 69 of each end.
– Compression posts to be located within 6” of expansion joints if applicable.
– All compression post notched at ends to fit over bulb of main runner.
– Compression post fastened to main runners with type S coated steel screw or equivalent
– 33 ksi min steel.