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I . <br /> Daniel W. DUnzik Architect LEED-AP <br /> 370 Burnt Hill Rd.Skillman NJ.08558 908-872-3664 <br /> StudioGdesign@comcast.net October 15,2020 <br /> Gravity Load Calculation Criteria <br /> Structural Design Loads per ASCE 7-10 <br /> Dead Loads=10 psf+2.6 psf(new solar panels)= 12.6 psf <br /> Roof Live Load=20 psf <br /> Ground Snow Load/Live Load=0 psf <br /> Wind Load Calculation Criteria <br /> Wind Loads per ASCE 7-10,Ch.30 method 1 <br /> Using an area of 10 SF,wind loads from Figure 30.5-1: <br /> Zone 1=-34.7 psf Roof Slope= 14'degrees Roof Mean Height= 15 ft <br /> Zone 2=-60.4 psf Basic Wind Speed= 145 mph <br /> Zone 3=-89.3 psf Exposure=B <br /> Per section 2.4.1,ASD combo=D+0.6W: <br /> Zone 1=2.6 psf+0.6(-34.7 psf)=-18.2 psf <br /> Zone 2=2.6 psf+0.6(-60.4 psf)=-33.6 psf <br /> Zone 3=2.6 psf+0.6(-89.3 psf)=-51 psf <br /> Check Attachment to Wood Truss <br /> Use 5/16 dia.Lag screw w/3"embedment into 2 in.wide roof rafter <br /> Lag Screw Spacing: Lag Screw Tributary Area: <br /> Zone 1= 48"o.c.max Zone 1=(48"o.c.max)^2/144=16 SF <br /> Zone 2= 24"o.c.max Zone 2=(24"o.c.max)^2/144=4 SF <br /> Zone 3= 24"o.c.max Zone 3=(24"o.c.max)^2/144=4 SF <br /> Lag Screw Forces: W=266lb/in(Table 12.2A,2015 NDS) <br /> Zone 1 = 18.2 psf x 16 SF=291 lb, < W', OK Cd=1.6(Table 2.3.2,2015 NDS) <br /> Zone 2=33.6 psf x 4 SF= 134 lb < W', OK Ct=1 (Table 2.3.3,2015 NDS) <br /> Zone 3=51 psf x 4 SF=2041b < W', OK W'=W x embed x Cd x Ct <br /> W'=266 lb/in x 3 in.xl.6 x 1 = 1276.8 lb <br /> I <br /> I <br />