The typical live load placed on a structure s roof varies by the building s use and location and weather is the primary concern.
Is it okay to use 6x2 in roof struts.
The decking is sized to resist the bending caused by these loads.
The minimum plywood for roofing.
Rafters run from the peak of the roof.
The live loads a truss is required to bear are determined by local building codes.
Hi there 5x2 graded timber for rafters and ceiling joist as 6x2 is only used in loadbearing situations and would be cheaper than 6x2.
Purlins are placed under rafters in a perpendicular position on edge not flat.
Tie to roof rafters at peak tie to ceiling joists roof rafters to ceiling joists at the eaves.
Answered 23rd feb 2011.
The spacing between rafters in a given building is part of the engineering calculations that determine the required structure of the roof.
The purlins are supported by vertical or slightly angled bracing.
Load tables specifying safe loads for different spans are available from metal deck manufacturers.
No need for purlins it would be a steel beam you would need to use but that is not necessery as it is only a lean to roof.
The ceiling joists create a truss to begin with i m suggesting adding another member to the truss.
The braces struts or kickers should be within every 4 and should not be at a greater than a 45 degree angle towards the roof slope lower side.
If the bottom chord of a roof truss functions as a floor joist such as in an attic room it carries a live load that also varies by.
Roof decking is often also used as a diaphragm to transfer wind or seismic loads to the lateral bracing system below.