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IS 14687:1999 is the Indian Standard (BIS) for formwork - code of practice. This code provides guidelines for the design, fabrication, erection, and dismantling of formwork for concrete structures. It covers the loads to be considered, material specifications for timber, steel, and plywood, recommended striking times, and safety requirements during formwork operations.
Lays down the requirements for the design, erection, use and dismantling of formwork for concrete construction.
Overview
Status
Current
Usage level
Frequently Used
Domain
Structural Engineering — Construction Safety and Practices
BIM-relevant code. See the BIM Hub for ISO 19650, IFC, and LOD/LOIN frameworks used alongside it.
Practical Notes
! Stripping times in Table 1 are minimums for OPC cement at temperatures above 15°C and must be increased for cold weather, special cements (like PPC/PSC), or complex structures.
! Proper application of a suitable mould-release agent is critical to prevent concrete surface damage and ensure easy striking of forms.
! Pay close attention to joints between formwork panels and tie-rod holes to prevent grout leakage, which can lead to honeycombing and aesthetic defects.
Both are comprehensive guides covering the design, construction, materials, and safety of formwork systems.
BS 5975:2019British Standards Institution (BSI), UK
MediumCurrent
Code of practice for temporary works procedures and the permissible stress design of falsework
Covers all temporary works; its falsework section is highly relevant but also includes extensive procedural controls not in IS 14687.
CSA S269.1-16 (R2021)CSA Group, Canada
HighCurrent
Falsework and formwork
Directly equivalent standard for the design, fabrication, erection, inspection, and dismantling of falsework and formwork.
EN 12812:2008European Committee for Standardization (CEN), Europe
MediumCurrent
Falsework - Performance requirements and general design
Focuses on performance requirements and structural design of falsework, a major component of most formwork systems.
Key Differences
≠IS 14687 is based on a Permissible Stress Design (PSD) methodology, which is an older approach. Most modern international standards, like CSA S269.1 and BS 5975, are based on the more robust Limit State Design (LSD) methodology.
≠IS 14687 provides prescriptive, time-based schedules for striking formwork (e.g., 3 days for slabs up to 4.5m). In contrast, ACI 347R emphasizes performance-based criteria, linking formwork removal to the in-situ concrete achieving a specified percentage of its design strength.
≠The UK's BS 5975 mandates formal procedural controls, including the appointment of a Temporary Works Coordinator (TWC) to manage all temporary works on site. IS 14687 lacks this formalized procedural and management framework.
≠Formulas for calculating lateral pressure from fresh concrete are simpler in IS 14687. ACI 347R provides more complex and updated equations that account for variables like chemical admixtures (retarders), cement type, and concrete density, reflecting modern concrete technology.
Key Similarities
≈All standards share the fundamental principle that formwork must be designed to safely support all imposed vertical and lateral loads (dead load of concrete, live load of workers/equipment, wind) without failure.
≈All codes recognize the critical importance of providing adequate foundations for the formwork, including the use of sole plates to distribute concentrated loads from shoring onto the ground or supporting structure.
≈The requirement for adequate bracing to ensure lateral stability of the formwork and falsework system is a core safety principle common to IS 14687 and its international counterparts.
≈All standards provide guidance on the use of common formwork materials like timber, steel, and aluminum, including considerations for their structural properties and condition.
Parameter Comparison
Parameter
IS Value
International
Source
Minimum Vertical Live Load (Workers & Equipment)
0.75 kN/m²
2.4 kN/m² (50 psf)
ACI 347R-14
Minimum Notional Horizontal Load (for Stability)
2% of the total vertical load applied at the top
2.5% of the characteristic vertical load
BS 5975:2019
General Vertical Deflection Limit
The lesser of Span/270 or 3 mm
Generally Span/360 of the member
ACI 347R-14
Tolerance for Vertical Alignment of Columns
±6 mm per 3m height
±6 mm per 3m height (1/4 in. per 10 ft)
ACI 117-10 (Referenced by ACI 347R)
Striking Time Basis (Soffit forms)
Prescriptive time in days, based on span and temperature.
Performance-based, requires concrete to achieve a specified strength, verified by testing.
ACI 347R-14
Design Responsibility Framework
Responsibility lies with the 'engineer'; roles are not formally defined.
Formal roles with defined responsibilities, e.g., Temporary Works Coordinator (TWC), Temporary Works Designer (TWD).
BS 5975:2019
⚠ Verify details from original standards before use
Key Values7
Quick Reference Values
Minimum stripping time for vertical forms (columns, walls)16 to 24 hours
Minimum stripping time for slab soffits (props to be refixed immediately)3 days
Minimum stripping time for beam soffits (props to be refixed immediately)7 days
Minimum period before striking props to slabs spanning up to 4.5m7 days
Minimum period before striking props to slabs spanning over 4.5m14 days
Permissible deviation in cross-section dimensions for columns/beams+12 mm, -6 mm
Permissible deviation from vertical (for heights up to 3 m)6 mm
Key Formulas
Pressure on Formwork (P) = Unit weight of concrete × Height of pour (modified by factors like pour rate, temperature, vibration)
Tables & Referenced Sections
Key Tables
Table 1 - Recommended Minimum Stripping Times
Key Clauses
Clause 5 - Materials
Clause 6 - Loads and Pressures on Formwork
Clause 7 - Design of Formwork
Clause 8.4 - Removal of Forms and Striking
Clause 10 - Safety
Annex B - Permissible Tolerances for Concrete Structures
What is the minimum time before removing column or wall formwork?+
16 to 24 hours, provided the concrete is sufficiently hard to not be damaged. (Table 1)
When can props be removed from a 4m span slab?+
After a minimum of 7 days. (Table 1)
What loads must formwork be designed for?+
It must be designed for dead load (self-weight, concrete weight), live load (workers, equipment), lateral pressure from fresh concrete, and environmental loads like wind. (Clause 6)
What is the acceptable tolerance for the verticality of a column?+
The deviation from vertical should not exceed 6 mm for every 3 meters of height. (Annex B)