Rafter Span Roof Span Tables

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Rafter span roof span tables.

Use this table to determine the maximum lengths of ceiling joists based on species of lumber joist spacing and joist size. For pitched roofs flat roofs and ceiling joists. Rafter spans can be extended slightly beyond what the rafter tables suggest when there is a cantelever extending beyond the supporting wall. 1 ft 0 3048 m.

Surveyors and structural engineers utilise data from tables below to help calculate the correct size strength and centres of roof timbers for the required spans and loadings. 2 are indicated below. So this table could accommodate a house with a total rafter span or house width of 32 feet. Roof rafter span use this table to determine the maximum lengths of roof rafters based on species and grade of lumber spacing dimensions load and slope.

1 1 based on the horizontal projection of the roof rafter span. Also available for the android os. The tables below give maximum spans for rafters and beams. Rafter span tables use these tables to determine lengths sizes and spacing of rafters based on a variety of factors such as species load grade spacing and pitch.

Live load is weight of furniture wind snow and more. Rafter spans for southern yellow pine douglas fir and eastern spruce. The figures are based on quality materials. The imposed uniformly distributed live load in the main span.

Douglas fir maximum horizontal roof rafter span for lumber grade selected structural and no. These span tables assume installation of at least three joists or rafters that are spaced not more than 24 on center. Straight line interpolation shall be permitted for intermediate spans and design values. Loads are calculated in accordance with table 3 1 of as nzs 1170 1 2002.

Visit the roof framing page for more information on cutting roof rafters and visit the roof pitch calculator for determining rafter lengths based on rise and run. The calculated spans assume fully supported members properly sheathed and nailed on the top edge of the joist or rafter. Dead load weight of structure and fixed loads 15 lbs ft 2. Keep in mind that these are maximums in other words shortening spans slightly will result in a more solid structure.

1 psf lb f ft 2 47 88 n m 2. Tables 2l and 2h list the sizes and spans for pergola or carport beams in low wind speed and higher wind speed areas. The spans in this table are based on a maximum supported rafter span of 16 feet where the supported span is the total horizontal distance spanned by the roof rafters divided in half not the diagonal distance or the length of the rafter. Span calculator for wood joists and rafters also available for the android os.