The same concept holds true for roof trusses.
Maximum spacing of roof trusses.
But in general it doesn t matter if the truss spacing is at 12 16 or 24 inches.
2x4f 2000psif 1100psie 1 8x10 2x6f 1750 psi f 950 psi f 1900 psi e 1 8x10.
So the space between rafters can be greater without reducing the maximum span.
Once you ve calculated the number of trusses you will need you should purchase the lumber.
The trusses should be a little longer than the exact width to allow for overhang and you will need sufficient trusses to mount across the length.
Spacing a live load deflection limited to l 240 maximum and use lumber properties as follows.
Spaced sheathing or 1x boards may be reduced slightly.
What dictates the truss design is the roof design snow load typically 20 or 30 psf in most of the u s.
Live load l 480 total load l 360 5 chases are to be located in center of span.
These standards are as follows.
Allowable spans for 2x4 top chord trusses using sheathing other than plywood e g.
The two deciding factors are spacing of trusses span of purlins and the max load purlins must handle.
You can solve them as simpl.
Common spacing for trusses on this type of building is often between 2 and 4 feet but trusses built with advanced designs may allow spacing as great as 8 or 12 feet.
6 refer to trussteel technical bulletin tb971125 for trussteel floor truss design criteria.
Putting the trusses into place.
Maximum chase width allowed is 24 inches.
Of course how many trusses a purlin spans over must be considered as it alters their moment and shear diagrams.