USG Exterior Ceiling Applications Systems Guide - Manual (Page 37)

36 USG Exterior Ceiling Applications
USG Drywall Suspension System
Test Record UL526C
Class 30 Uplift
System Components
Main runners DGL26 or DGLW26
Cross Tees DGL26 or DGLW26
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.
Gypsum Panels – 5/8 in. thick, 4 ft wide, installed with long dimension perpendicular to cross tees. End joints centered along
c1/2 in. thick, 4 ft wide, installed with long dimension perpendicular to cross tees. End joints centered along
cross tees, side joints to be centered along main runners.
– Gypsum board fastened to each cross tee with No. 8 by 1 in. long bugle head screws with one screw located
at midspan of cross tee and with additional screws located 12 in. o.c. beginning from center screw and with
screws located 1-1/2 in. from each gypsum board side joint. At gypsum board butt ends, a total of seven
screws used, with one screw located at midspan of cross tee and additional screws spaced 8 in. o.c. with
one screw located 1-1/2 in. from wall board side joint. All screws located max 1/2 in. from edge.
– End joints of adjacent sheets staggered min. 4 ft. Sheets fastened to lower leg of wall channel with screws
spaced max 12 in. o.c.
Type Max Unbraced Length (in)
Compression Posts 3/49 x 1/29 x 0.0599 channel 31
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 98
1-5/89 25 gauge steel studs, 0.01799 min (Back-to-back) 1130
– 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.
– All compression post notched at ends to fit over bulb of main runner.
– Compression posts to be located within 69 of expansion joints if applicable.
– Compression post fastened to main runners with type S coated steel screw or equivalent.
– 33 ksi min steel.