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Non-Tile Roof Tile Roof <br />Rafter SpacingAssumed <br />Vintage <br />Nominal <br />Size <br />Actual <br />Size <br />76" o.c 24" o.c 32" o.c t4 0.c 32" o.c. <br />2x4 7%"x3%"9'-70"8',,0"6', -6"8' -6"6'-71"5'-6" <br />2x6 t4'-4"7t'-9"9' -6"72',-5"1.O',-2"8'-0"Post-1960 <br />2x8 t%"x7%"78',-2"74',-10"12',-O"t5'-9"t2'-t0"10' -3" <br />8',-6"6',-9"2x4 1.%"x3%"1.r'-3"g',-9"7'-9"10'-3" <br />2x6 7%"x5%"77',-0"L4',-O"7r'-3"14'-9"72',-O"9' -9"Pre-1960 <br />1.%"x7%"22'-3"18',-0"14'-6"L9',-0"t5'-6"72'-6"2x8 <br />Table 2. Roof Rafter Maximum HorlzontdlSpan (fuet - inches)l <br />Beyond a visual review by the contractor checkingfor unusual sagging or deterioration, some CBOs may want <br />atlditional assurance lhat the roof structure complies with structural building code requirements. Table 2 is an <br />optional table some CBOs may elect to use to provide additional assurance by requiring a check of existing roof <br />rafter spans, and supports optional criteria 1.8.5 and 1.8.6. For post-1960 construction, these span tables match <br />the rafter span tables found in the 2013 Califurnia Building and Residential codes. For pre-1960 construction, the <br />rafter span tables are based on structural calculations with lumber sizes and wood species and grade appropriate <br />for older construction. Note 5 below lists the basic assumplions upon which this table is based. <br />Table 2 Notes: <br />l. See Figure 4 for definition of roof rafter maximum horizontal span. <br />2. "Non-tile Roof" = asphalt shingle, wood shingle and wood shake, with an assumed roofassembly weight <br />of l0 psf. <br />3. 'Tile Roof" = clay tile or cement tile, with an assumed roof assembly weight of20 psf <br />4. Unaltered manufactured plated-wood trusses may be assumed to be code compliant and meet intent of <br />Table 2. <br />5. This table is based on the following assumptions: <br />. Span/deflection ratio is equal to or greater than 180. <br />. For post-1960 construction, wood species and grade is Douglas Fir-Larch No. 2. <br />. For pre-1960 construction, wood species and grade is Douglas Fir-Larch No. l. <br />. Other wood species and/or grade are also acceptable if allowable bending stress is equal or greater to <br />that listed. <br />(Attach 'I'ablc 2 t)N l-Y ifthc Otxionfll Additional Raltcr Span (lhcck is addctl to the list ol Structural Criteria.) <br />76" o.c. <br />7%"\5%"