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�3 <br />A framing plan is required only if the combined weight of the PV array exceed 5 pounds per <br />square foot (PSF or lbs/ ft') or, the existing rafters are over -spanned. The following may help <br />determine if the rafters are over -spanned. <br />Use the table below for rafter spans that have conventional lightweight dead loads, and do not <br />have a ceiling attached. If there is a roof system that does not fall within these tables, provide a <br />roof -framing plan for review. <br />10 PSF Dead Load <br />Roof live load = 20 psf, ceiling not attached to rafters, L/A = 180 <br />Rafter Size <br />2 x 4 1 2 x 6 1 2 x 8 2x 10 2x 12 <br />Spacing <br />Species <br />Grade <br />The measurements below are in feet -inches <br />(inches) <br />(e.g. 9 - 10 = 9 feet, 10 inches) <br />Douglas <br />42 or <br />16 <br />Fir -larch <br />better <br />9-10 <br />14-4 <br />18-2 <br />22-3 <br />25-9 <br />Douglas <br />42 or <br />24 <br />Fir -larch <br />better <br />8-0 <br />11-9 <br />14-10 <br />18-2 <br />21-0 <br />Use this table for rafter spans with a ceiling attached, and conventional light dead loads <br />10 PSF Dead Load <br />Roof live load = 20 psf, ceiling not attached to rafters, L/A = 240 <br />Rafter Size <br />2 x 4 1 2 x 6 1 2 x 8 2x 10 2x 12 <br />Spacing <br />Species <br />Grade <br />The measurements below are in feet -inches <br />(inches) <br />(e.g. 9 - 10 = 9 feet, 10 inches) <br />Douglas <br />42 or <br />16 <br />Fir -larch <br />better <br />8-11 <br />14-1 <br />18-2 <br />22-3 <br />25-9 <br />Douglas <br />42 or <br />24 <br />Fir -larch <br />better <br />7-10 <br />11-9 <br />14-10 <br />18-2 <br />21-0 <br />If the roof system has: <br />a. Over -spanned rafters or trusses, <br />b. The array is over 5 lbs/ft2 on any roof constriction, or <br />c. The attachments with a dead load exceeds 45 lbs per attachment; <br />It is required that you provide a framing plan showing details how this will strengthen the <br />rafters using the supplied span tables. <br />3 The Span Tables and Exhibits B & C were printed with permission from the Solar America Board of Codes & Standards. <br />