Installation should include
- interpreting the rafter layout according to plans
- computing the rafter length
- laying out for a specified pitch and birdsmouth as required for cutting
- using fasteners according to specifications.
IRC: Chapter 8 furnishes span tables for a variety of rafters and live and dead load combinations. Also included are details on rafter cut tolerances and attachment methods approved by code.
Process/Skill Questions:
- What determines the spacing and size of rafters?
- How can rafters be installed? What are the advantages and disadvantages of each method?
- What are the differences among common, header, and cripple rafters? In what situations should each be used?
- What plans should be referenced when reading and laying out rafters?