What a truss manufacturer needs from you
The trusses over your house are designed by the company that builds them. They work from your drawings and your site's loads.
What they ask for
- The span, the roof pitch and the truss spacing.
- The heel height and the overhangs.
- The design loads: your site's snow load and wind speed, and the roof's own weight.
- Where the trusses bear, and anything they carry besides the roof.
Where to find it
The roof framing plan in the set gives span, pitch, spacing, heel and the baseline loads. Your building department gives the loads for your site.
What comes back
Truss design drawings with member sizes, plates, reactions and bracing. Your builder orders connectors from them, and your building department usually wants them with the application.
Source: the model residential code asks for truss design drawings prepared for the building (IRC Section R802.10.1).