Would you like to save your current project before starting a new one?
Any unsaved changes will be lost.
Choose a beam or rafter. Inputs and calculations belong to that element and are included when you save the project. Dimensions are read from the Roof Planner.
Each load starts at the centre. Edit its position in mm from the beam’s drawn start (left support in the diagram), or use Centre to reset it.
Click an area on the preview or tick its name. Set the share transferred to this beam: 50% for uniformly loaded rafters shared by two end supports, or 100% for a load already calculated at this beam.
All named areas are available here, including areas hidden in the planner. Selected contributions are spread evenly along the full beam length and replace the uniform load. No load factors are added.
Enter the total vertical load from the roof area feeding this beam on each side. Use 0 for an unused side.
The result fills the uniform load above and replaces its previous value. Assumes the transferred load is spread evenly along the full beam length. No load factors or self-weight are added.
Floor mode uses the three loads below in place of the existing uniform, point, roof and module loads. Existing values are retained for when floor mode is disabled. This load case is for serviceability; bending results are unfactored screening.
Single simply supported span; mean stiffness and density come from the selected timber grade. The existing deflection-limit field sets the combined instantaneous project limit. G: L/400 instantaneous and final; Q: L/600 instantaneous.
Find the smallest cross-sectional area that passes the entered bending strength and deflection limit. Sizes are width × height; the span, material and loads stay the same.
Only multiples of the size step are searched. Fixed-width mode keeps the exact current width and uses only the height limits. Equal-area sections favour the lower height. These are calculated dimensions, not a supplier stock list.
Uses the screening checks above. Lateral stability, shear, bearing, connections and stock availability are not checked; a narrow, deep section still needs those checks. Self-weight is not added automatically.