02 · Approved spacing
Enter spacing from your approved design. The preset applies Vidaform practice as a convenience — it is not approval.
Distance between main (WTD) beam lines
Timber 2"×4" under plywood
Presets follow the Vidaform calculation sheet (28 cm → 1.2×1.8 @35 cm; 40 cm → 1.2×1.6 @30 cm).