Scaffold safety & technical guidance
A practical guide to TG20, TG30, SG4, scaffold inspections, design, permits and project responsibilities.
This is a client-facing overview for Great Britain, not scaffold erection instructions or a site-specific design. Northern Ireland has separate legislation; use HSENI guidance for those projects. The linked technical publications contain the full requirements.
Law, guidance and technical standards
The Work at Height Regulations 2005 set legal duties for work at height in Great Britain. TG20 and SG4 are industry guidance; British Standards are technical references. These are different things, and none is a general company approval certificate.
The risk-control sequence is to avoid work at height where reasonably practicable, prevent falls where it cannot be avoided, and minimise the distance and consequences of a fall where risk remains. Consider collective protection before personal protection.
TG20:21: tube-and-fitting scaffolding
TG20 provides recognised standard configurations for tube-and-fitting scaffolds. The relevant compliance sheet must match the proposed scaffold and its stated parameters. A generic sheet for another job is not evidence for your installation.
Where an arrangement falls outside the recognised configuration, obtain a competent, project-specific design rather than assuming the standard sheet covers it.
NASC announced additional ePortal options for 1.5 m lifts and returns on 4 September 2026, with updated online guidance. Use the current applicable guidance and software outputs, not an old screenshot.
TG30: system scaffolding
TG30 is NASC’s guidance and compliance-sheet route for supported system-scaffold configurations. TG20 applies to tube and fitting. Check the actual system, manufacturer’s instructions and the scope of the available configuration; do not treat the two guidance routes as interchangeable.
SG4:22: preventing falls during scaffolding work
NASC lists SG4:22, also styled SG04:22, for preventing falls during scaffolding operations. It addresses safe methods of erection, alteration and dismantling, including the Scaffolders’ Safe Zone approach. Fall prevention must be planned into the method of work; a helmet or harness on its own does not establish a safe working method.
The scaffold design brief
Tell the scaffold provider the location, intended use, required duration, dimensions, working lifts, access arrangements and proposed loads. Identify sheeting, netting, loading bays, hoists, restricted tie positions, ground conditions and relevant building information.
The agreed design information should explain the scaffold arrangement and its limitations. Ask which drawings or compliance sheets apply, who checks the design and how changes will be controlled.
Temporary works coordination and design control
Scaffolding interfaces with the project’s temporary works arrangements. Agree who coordinates design information, site interfaces, changes and authorisation to use the completed arrangement.
BSI published BS 5975-1:2024 for temporary works management procedures and BS 5975-2:2024 for falsework design and implementation. Part 2 is about falsework; it is not a universal design instruction for every access scaffold. BS EN 12811-1:2003 addresses scaffold performance requirements and general design. The competent designer selects the relevant standards.
Inspections, reports and visible tags
HSE says construction scaffolds should be inspected before first use, at intervals no greater than seven days, and after events likely to affect safety, such as adverse weather or substantial alteration. The inspector’s competence must suit the type and complexity of the scaffold.
Agree who arranges inspections and keeps the reports. Record defects and corrective action. A visible tag can help communicate inspection status, but it supplements the report; a tag system itself is not a legal requirement. Stop using an affected area and raise defects with the responsible site team.
Handover and first use
Before access is released to users, agree the handover arrangements and the first inspection. Obtain the relevant scaffold identity, design or compliance information, intended use, loading restrictions, access details and any limitations or incomplete areas.
NASC SG35:21 covers handover, completion checks, documentation, communication of safe-use information and the first scaffold inspection. Handover is part of the process; ongoing inspection duties continue during use.
Loads, sheeting, weather and alterations
Tell the scaffold designer and erector before adding sheeting, debris netting or other attachments. These can change the forces on the scaffold, including wind effects. Agree the permitted loads and loading-bay use before materials are stored.
Do not let other trades remove ties, boards, guardrails or braces. Changes to use, loading or the scaffold arrangement need review by the responsible scaffolding team. Ask the provider for the weather restrictions applicable to the actual design and site conditions.
Safe access, edge protection and site security
Plan access early. NASC SG25 discusses the access hierarchy, including stair towers and ladder access bays, and the need to secure access equipment and prevent unauthorised use.
For construction scaffolds, HSE describes a top guardrail at least 950 mm above the working platform, gaps no greater than 470 mm and suitable toe boards. The full arrangement must still be assessed for its intended use; these dimensions alone do not demonstrate compliance.
Protecting residents, neighbours and the public
Identify entrances, footpaths, boundaries, occupied premises, delivery routes and vulnerable users at planning stage. Control the risk of falling tools or materials and keep pedestrians separate from deliveries and scaffolding work.
Agree suitable barriers, protected routes and site security. Review netting, brickguards, fans or covered walkways where needed, as part of the designed arrangement. Keep children and other unauthorised people off the scaffold, including outside working hours.
Highway licences and local conditions
Scaffolding or hoarding on the public highway requires the relevant highway authority’s permission. The GOV.UK licence finder covers England and Wales and helps identify the local council. Agree who applies, who pays and who monitors the licence conditions before installation.
Application lead times, fees, lighting, pedestrian clearances and other conditions vary by authority and site. A private-land agreement does not replace a highway licence. Check the correct local requirements for projects in other UK jurisdictions.
CDM 2015: who does what?
Commercial clients must make suitable project-management arrangements and provide relevant information. Designers consider foreseeable risks. Where more than one contractor is involved, the principal designer coordinates pre-construction health and safety and the principal contractor coordinates the construction phase.
Contractors plan and manage the work they control and cooperate with the project team. Domestic client duties normally pass to the contractor on a single-contractor project or the principal contractor on a multi-contractor project, subject to the arrangements described by HSE. Confirm responsibilities for the actual project.
Competence, supervision and workforce evidence
Check that the people appointed have training and experience appropriate to the scaffolding and tasks involved. CISRS provides routes for scaffolders, advanced scaffolders, supervisors, inspectors and system-scaffold training. Check the relevant role, endorsements and card validity through current scheme instructions.
Trainees need suitable supervision. A card or course title is one part of the evidence, not a substitute for matching competence to the job. Company memberships, individual qualifications and a site-specific scaffold design should be checked separately.
Risk assessment, method statements and rescue
Assess the actual work and select controls before work begins. The method statement should explain how the planned sequence and controls will be implemented, communicated and supervised; it should reflect the site rather than a generic job description.
Plan emergencies and rescue before work at height starts, including the people, equipment and arrangements needed. HSE says the rescue plan should not rely on the fire brigade. Discuss fragile surfaces, occupied areas and changes to site conditions with the responsible project team.
Equipment, lifting, manual handling and incident reporting
- PUWER covers work-equipment suitability, inspection, maintenance and relevant training.
- Where lifting equipment or lifting operations are involved, consult the applicable LOLER requirements and organise competent planning and examination.
- Assess manual handling and reduce avoidable handling of materials and components.
- RIDDOR sets reporting requirements for specified injuries, diseases and dangerous occurrences. Use HSE’s guidance to establish who reports and whether an event is reportable.
What to request from a scaffolding contractor
- An agreed scope and project contact.
- The applicable design or compliance sheet, and safe-use information.
- Handover and inspection arrangements, with responsibility for records.
- Relevant competence information and current insurance / accreditation evidence.
- A clear process for changes, hire extensions and dismantling.
NASC states that its ePortal can be used by members and non-members. Producing a TG20 or TG30 compliance sheet does not by itself establish NASC membership. Request and verify each type of evidence separately.
Materials, components and current product references
Material standards, product records and the completed scaffold design answer different questions. Confirm which components and systems are proposed and which documents apply to them. Equipment suitability and condition still need checking for the actual work.
| Reference | Subject | Status and enquiry point |
|---|---|---|
| BS EN 39:2001 | Steel tubes for tube-and-coupler scaffolds | BSI marks this edition withdrawn on 21 May 2026. Do not describe it as a current standard. Confirm the applicable specification and equipment evidence with the designer or supplier. Official reference ↗ |
| BS EN 74-1:2022+A1:2025 | Couplers for tubes | BSI lists this edition as current. It addresses coupler requirements and tests; it is not a site-specific scaffold design or a company accreditation. Official reference ↗ |
| BS 2482:2009 | Timber scaffold boards | BSI lists this edition as current and under review. Check the applicable board specification and supporting product information. Official reference ↗ |
| BS EN 1004-1:2020 / BS EN 1004-2:2021 | Prefabricated mobile access towers and instructions | PASMA distinguishes the tower product standard from the instruction-manual standard. This is a specific equipment category, not a standard for every scaffold tower or access scaffold. Official reference ↗ |
These references do not certify Heathrow Scaffolding’s equipment or replace the designer’s specification. Ask for relevant product identification, inspection or maintenance records and manufacturer’s instructions. The withdrawal of a standard alone does not determine whether particular equipment is suitable for a site.