Laserfiche WebLink
SolarMount Unirac Code-Compliant Installation Manual :FUNIRAC <br />Step 6: Determine the Uplift Point Load, R (lbs), at <br />each connection based on rail span <br />You must also consider the Uplift Point Load, R (lbs), to <br />determine the required lag bolt attachment to the roof <br />(building) structure. <br />Table 11. Uplift Point Load Calculation <br />Total Design Load (uplift): P psf Step I <br />Module length perpendicular to rails: B x ft <br />Rail Span:L x ft Step 4 <br />Uplift Point Load: R lbs <br />Table 12 Lag pull-out (withdrawal) capacities (lbs) in typical roof lumber (ASD) <br />Log screw specifications <br />Spedfic 5/5.- shall* <br />gravity per inch thread depth <br />Douglas Fir, Larch <br />Douglas Fin South <br />Engelmann Spruce, Lodgepole Pine <br />(MSR 1650 f & higher) <br />Hem, Fir, Redwood (close grain) <br />Hem, Fir (North) <br />ad <br />Southern Pine >th <br />Spruce, Pine, Fir <br />Spruce, Pine, Fir <br />(E of 2 million psi and higher <br />grades of MSR and MEL) <br />Sources:American Wood Council NDS 2005, Table / /.24 1 1.3.2A <br />0.50 266 <br />0.46 235 <br />0.46 235 <br />0.43 212 <br />0.46 235 <br />Thre <br />0.55 307 deT <br />0.42 205 <br />0.50 266 <br />/1 <br />Use Table 12 to select a lag bolt <br />size and embedment depth to <br />satisfy your Uplift Point Load <br />Force, R (lbs), requirements. <br />Divide the uplift pointload (from <br />Table 11) bythewithdrawal <br />capacity in the 2nd column of <br />Table 12. This results in inches <br />of 5/161agbolt embedded thread <br />depth needed to counteract the <br />uplift force. If other than lag <br />bolt is used (as with a concrete <br />or steel), consult fastener infr <br />documentation. <br />It is*the installer's responsibility <br />to verify that the substructure <br />and attachment method is <br />strong enough to support the <br />maximum point loads calculated <br />according to Step 5 and Step 6. <br />Notes: (/) Thread must be embedded in the side grain of a rafter or other structural member integral with the <br />building structure. <br />(2) Lag bolts must be /ocated in the middle third ofthe structural member. <br />(3) These values cre not va/id for wet service. <br />(4) This table does not include shear capacities. Ifnecessary contact a localengineer to specitiy lag bok size <br />with regard to shear forces. <br />(5) insta# log bolts with head and washer Bush to surface (no gap). Do not over-torque. <br />(6) Withdrawal design values for log screw connections shall be multiplied by applicable adjustment factors if <br />necessary. See Table 10.3.1 in the American Wood Council NDS forWood Construction. <br />*Use flat washers with lag screws. <br />Page <br />13