SmartLVL 15 Design Guide - Tilling Timber

Strutting beamNOTESUnderpurlinRafterspacingRoof strutSmartLVL 11UNDERPURLINS – SHEET AND TILED ROOFAS 4055 WIND CLASSIFICATION N1, N2, N3 & C1Ridge board'X' = Total of rafter spanseither side ofunderpurlinEXAMPLE:single spansheet roof - 20 kg/m 2rafter spacing = 1200 mmunderpurlin span = 1800 mmX = 2800 mmroof load width = X/2 = 1400Enter single span table at 2700 roof load width column,1200 rafter spacing and read down to span equal to orgreater than 1800 mmWAADOPTSpanSpan (backspan)Maximum cantilever = 1/4 allowable backspanMinimum backspan = 3 x actual cantileverRLW = X/2 where ridge is struttedEnd bearing lengths = 45 mm at end supports and 45 mm at internal for continuous members.SmartLVL 11 96 x 51Roof load width (mm) 1800 2700 3000 3600 1800 2700 3000 3600Rafter spacing (mm) 600 1200 600 1200 600 1200 600 1200 600 1200 600 1200 600 1200 600 1200Member sizeDxB (mm)Roof mass(kg/m 2 )Single spanContinuous span96x51 10 2900 2900 2600 2600 2500 2500 2300 2200 3300 3300 2700 2700 2600 2600 2300 250020 2300 2400 2000 2000 1900 1900 1800 1800 3000 3000 2700 2600 2600 2600 2400 250040 1800 1800 1600 1500 1500 1400 1400 1300 2500 2500 2100 2000 2100 2000 1900 190060 1600 1500 1400 1200 1300 1100 1300 1000 2100 2000 1800 1800 1800 1800 1700 1500Only'B' Total of'A' Total ofUnderpurlinspansRoof Area supported = A/2 x B/2where Ridge is struttedROOF STRUTS – SHEET AND TILED ROOFAS 4055 WIND CLASSIFICATION N1, N2, N3 & C1Propped RidgebeamRafter spansUnderpurlinRoofStrutNOTE: See fixingdetails of SmartLVL11 roof struts onEXAMPLE:sheet roof - 20 kg/m 2strut length = 1500 mmtotal of underpurlin span A = 4.5 mtotal of rafter span B = 4.0 mroof area supported = A/2 x B/2 =4.5/2 x 4.0/2 = 4.25 m 2Enter table at 5.4 roof area supported column and readdown to span equal to or greater than 1500 mmADOPTSmartLVL 11 65 x 63NOTES :Roof area supported (m 2 ) 2 4 5.4 6 8 10 12Member sizeDxB (mm)Roof mass (kg/m 2 )Maximum Strut length (mm)65x63 10 5600 4800 4100 3900 3400 3000 270065x63 20 5400 4500 3900 3700 3200 2900 260065x63 40 5000 4100 3600 3400 2900 2600 240065x63 60 4700 3800 3300 3100 2700 2400 22001. D = member depth, B = member breadth, NS = not suitable.2. Minimum bearing length = 70 mm at end supports3. The strutting tables in AS 1684 are based upon the load associated with an underpurlin span of 1.8 m and a roof load width of 3.0 m. To compare to AS1684.2 Table 7.6, use a roof area of 5.4 m 2 in the above table4. Fixing of SmartLVL roof struts as per detail on page 6SmartLVL 15 Design Guide (WA Supplement) 89