Title: Listeskrue 3,5x45.pdf
Dead load dL and snow load sLWpesRafteresPressure transfer within the insulationAxis of screw, tension load FzβConcentrated transfer of pressure within the insulation= = =Wind suction Spacing of screws Roof inclinationWP lef α= = =Wind pressure Thread part part of screw in rafter Angle between axis of screw and axis of rafterfischer Power-Fast and Construction ScrewsFixing of on-roof insulation systemAnnex B1 of European Technical Assessment ETA-11/0027Page 34 of 37 of European Technical Assessment no. ETA-11/0027, issued on 2016-10-26Design of the battensThe bending stresses are calculated as:M(F  bF ) s 4 Wherecharchar = characteristic lengthchar44 EI  w K  efEI = bending stiffness of the batten K = coefficient of subgrade wef = effective width of the heat insulation Fb = Point loads perpendicular to the battens Fs = Point loads perpendicular to the battens, load application in the area of the screw heads