IS 15647:2006 is the Indian Standard (BIS) for timber formwork for concrete - code of practice. This code provides guidelines for the design, fabrication, erection, and stripping of timber formwork for concrete structures. It covers material specifications, design loads, permissible stresses in timber and plywood, and safe practices for erection and removal, including minimum striking times.
Provides guidelines for the design, construction, and removal of timber formwork for concrete structures.
BIM-relevant code. See the BIM Hub for ISO 19650, IFC, and LOD/LOIN frameworks used alongside it.
| Parameter | IS Value | International | Source |
|---|---|---|---|
| Minimum Construction Live Load (deck) | 2.0 kN/m² (for normal working area) | 2.4 kN/m² (50 psf) for workers and equipment | ACI 347R-14 |
| General Deflection Limit for Flexural Members | Span / 270 | Span / 270 (for surfaces where finish is of consequence) | AS 3610.1:2018 |
| Verticality Tolerance (up to 3m height) | ±6 mm (as per referenced IS 456) | ±6 mm (±1/4 inch per 10 ft) | ACI 117-10 (referenced by ACI 347R) |
| Horizontal Wind Load (Minimum) | Not less than 1.0 kN/m² of the vertical projection | Not less than 15 lbf/ft² (0.72 kN/m²), but requires calculation based on local codes (e.g., ASCE 7) | ACI 347R-14 |
| Permissible Stress Increase for Wind Load | 25% increase in permissible stresses for timber | Load combinations are used (Limit State Design), no direct stress increase factor is applied in the same way. | BS 5975:2019 |
| Re-propping Requirement | Permitted, but loads on supporting slabs must be carefully checked. | Permitted, with detailed guidance on load distribution and checking capacity of supporting floors (backpropping). | AS 3610.1:2018 |