in the us they are typically spaced at fractions of the roof sheathing size. since most sheets are 4'x8', typical rafter spacing are 12', 16', 24'. in california, 16' is by far the most common for residential construction.
the industry standard spacing for pin holes for adjustable cabinet shelving is 1-1/4' on center and all 4 holes coplanar, however this spacing can vary from 1-2' depending on the manufacturer.
joists or rafters that are spaced not more than 24' on center. the calculated spans assume fully supported members, properly sheathed and nailed on the top edge of the joist or rafter. strht-line interpolation shall be permitted for intermediate spans and design values. 2. lumber design values use of these span tables requires reference to the
standard pergola rafter spacing there are two standard rafter spacings, and not coincidentally, theyre the exact same as the joist spacing used beneath floors. the measurements are 12 inches and 16 inches off center rafter-to-rafter.
thru-bolts w/ washers , per connection as shown for headers or rafters- two 2x members may be substituted for one 4x member. see tables a and b for span limits. 1. use a continuous 2x ledger same depth as rafter or larger 2.
lean-to rafter spacing? we're planning a quick lean-to addition in a few weeks when i have a couple vacation days due. our existing barn is a typical pole barn with 12' eaves and 2x6 top chords on the trusses.
you can easily go 12 feet with 2x6's on a metal roof with a 4:12 pitch. even 2:12, but then you start to push the limits of what it can shed during a heavy rain without leaking. if you are going with shingles, then that additional weight means you need to stay at 24 inch centers
what i need to know is what size beam will be required for a 6 meter single span and post sizes? and what my rafter sizes and spacing should be? cheers more clarity needed, is the pergola 6m x 6m?
pergola rafter spans for 600 mm and 900 mm spacing. notes: 1 refer to general notes for information that is relevant for all span tables. 2 for design parameters, refer to figure 7.26. as1684.2 and 3. 3 where rafters are equal to or exceed four times their breath, blocking should be used to reduce distortion.
for instance if the rafters happen to be 24 feet long that means that the run is 12 ft and if the height from the bottom of the rafter to the peak is 8 feet then you have a 8/12 pitch roof.
rafter span tables. use these two tables for roof rafters with a slope of 3' in 12' or less. use these two tables for roof rafters with a slope greater than 3' in 12'. the above spans are based on american softwood lumber standard sizes.