Timber rafters and floor joists carry significant loads within a residential structure and need to be properly sized for their span, spacing, loading, support conditions, and timber properties. A well-designed framing system helps control deflection, vibration, and overstress while providing a clear load path through the building.
Rafter Design
Roof rafters can be designed based on roof dead loads, live loads, snow loads where applicable, roof covering, ceiling loads, spacing, span, pitch, and support conditions. Design checks may include bending, shear, deflection, bearing, and stability.
Joist Design
Floor joists are evaluated for the expected floor loading, clear span, joist spacing, support conditions, and serviceability requirements. Calculations can address bending, shear, deflection, vibration considerations, and bearing at supports.
Framing Coordination
Rafters and joists should be coordinated with beams, walls, headers, posts, and foundations so loads transfer correctly through the structure. Framing plans can identify member sizes, spacing, direction, support points, openings, and required connections.
What We Can Provide
- Timber rafter sizing
- Floor joist sizing
- Span and load calculations
- Deflection checks
- Bearing checks
- Roof framing plans
- Floor framing plans
- Member schedules
- Connection and support details
- Detailed timber framing drawings
- Permit documentation
Send the architectural plans, roof and floor layouts, spans, project location, and available design criteria. We can develop the required rafter and joist design together with structural calculations and detailed framing documentation.