BS 1139 Standard

BS 1139 is a British Standard that specifies requirements for metal scaffolding components used in construction and industrial applications. It ensures the safety, quality, and compatibility of scaffolding systems, covering materials, dimensions, load capacities, and performance criteria.

Purpose:

BS 1139 is designed to ensure the safety, reliability, and consistency of scaffolding materials and systems. It covers various aspects of scaffolding, including tubes, couplers, fittings, and even specific types of scaffolding structures like prefabricated tower scaffolds.

Scope:

The standard is divided into several parts, each addressing different components or types of scaffolding. For example, BS 1139-1 focuses on scaffolding tubes, while BS 1139-2 covers couplers and fittings.

Scaffold Tubes

• Material: Typically made from steel (galvanized or ungalvanized).
• Dimensions: Standard outside diameter of 48.3 mm (nominal bore of 40 mm).
• Wall Thickness: Minimum 4 mm for steel tubes.
• Length: Commonly supplied in lengths of 6.4 m (21 ft), but other sizes may be available.
• Mechanical Properties: Tubes must meet certain mechanical requirements, such as tensile strength and elongation, to ensure they can withstand the loads and stresses encountered during construction.

Scaffold Fittings (Couplers & Accessories)

• Types:

     Right-Angle Couplers – For connecting tubes at 90°.

     Swivel Couplers – For angled connections.

     Sleeve Couplers – For joining tubes end-to-end.

     Putlog Couplers – Used in single-pole scaffolding.

• Material: Drop-forged steel or pressed steel.
• Load Capacity: Must meet specified strength requirements (e.g., slip resistance, torque resistance).
• Design and Testing: BS 1139 includes detailed requirements and test methods for couplers and fittings to ensure they can securely connect and support scaffolding tubes.

Galvanization & Corrosion Protection

Scaffold tubes and fittings may be hot-dip galvanized for corrosion resistance, especially in harsh environments.

BS 1139-1:

This part focuses on the specifications for scaffolding tubes, including material requirements, dimensions, and manufacturing methods.

BS 1139-2:

It covers couplers and fittings, providing detailed requirements and test methods for these components.

BS 1139-6:

This part specifies requirements for the structural design of prefabricated tower scaffolds that use components from mobile access and working towers specified in BS EN 1004 but in configurations outside the scope of that standard. It covers various types of tower scaffolds, such as those with multiple working platforms, large deck towers, and linked towers.

• BS 1139 aligns with UK and international scaffolding standards, including EN 39 (European standard for scaffold tubes).
• Regular inspection of tubes and fittings is required to prevent defects (e.g., rust, deformation).

• Used in tube-and-fitting scaffolding systems for construction, maintenance, and industrial access.
• Ensures structural integrity and safety in temporary structures.

Overall, the BS 1139 standard plays a crucial role in ensuring that metal scaffolding components and systems meet high safety and quality standards, contributing to safer construction practices.