Scaffold Inspection Requirements UK: Weekly Checks & TG20

Summary

Scaffold collapses are one of the leading causes of fatal and major injuries in the UK construction industry. Despite this, scaffold inspection is frequently neglected — particularly on smaller domestic jobs where a scaffold is erected, signed off once, and then used for weeks without further check.

The Work at Height Regulations 2005 (WAHR 2005) place a statutory duty on the person controlling the work (the principal contractor or self-employed tradesperson) to ensure that any working platform is inspected by a competent person before first use and at least every 7 days. This applies to every scaffold used in the workplace — including domestic and residential projects.

TG20:21 (Guidance for scaffolding using tubes and fittings) is the industry standard guide produced by NASC (National Access and Scaffolding Confederation). It replaced TG20:13 in 2021 and is delivered through the NASC ePortal, which hosts the TG20 eGuide software, Design Guide and Operational Guide on subscription. It provides a prescriptive specification for standard scaffold configurations so that a separate structural design is not required. If the scaffold conforms to TG20:21, a competent scaffolding contractor can erect it and issue a TG20 compliance sheet. If the scaffold is non-standard (unusual loading, cantilevers, complex configuration), a bespoke structural design is required.

Since November 2024 there is a companion document for system scaffolds — TG30:24 — which does for proprietary system scaffolding (Layher, Haki, Peri and similar) what TG20 does for tube and fitting. Between them, TG20:21 and TG30:24 cover the great majority of scaffolds a tradesperson will encounter.

If you have older paperwork or a contractor still quoting "TG20:13", that reference is out of date. Ask for a current TG20:21 compliance sheet (or a TG30:24 / manufacturer's compliance document for system scaffold), or a bespoke design drawing.

Key Facts

• Legal basis: Work at Height Regulations 2005 (SI 2005/735), Regulation 12 — inspection of work equipment at height. Construction (Design and Management) Regulations 2015 (CDM 2015) — duty on principal contractor to ensure scaffold is inspected
• Inspection frequency: Before first use, and at intervals not exceeding 7 days, and after any event likely to affect the scaffold's stability (storm, adjacent excavation, vehicle impact)
• Competent person: Must have sufficient knowledge, experience, and training to assess scaffold safety. Typically a CISRS (Construction Industry Scaffolding Record Scheme) card holder, or an experienced site supervisor with scaffold safety training. Not necessarily a scaffolding contractor — a competent site manager can carry out weekly checks
• Inspection record: Must be in writing, completed before the end of the working day on which the inspection is carried out. The particulars required are set out in Schedule 7 of the Work at Height Regulations 2005 — not PUWER. It must record any defects or matters that could give rise to a risk to health and safety and any corrective action taken, even where the defect was put right straight away. ScaffTag systems provide a visual check-tag on the scaffold — these complement but do not replace written records
• TG20:21: Published by NASC (replacing TG20:13). The reference standard for tube-and-fitting scaffolding in the UK. Provides bay width, lift height, and loading tables for standard configurations. The TG20 eGuide produces a PDF compliance sheet with the information needed to build the specified scaffold. If any dimension or configuration falls outside TG20:21, a bespoke design is required
• TG30:24: Published by NASC in November 2024. The equivalent compliance framework for system scaffolding, comprising an eGuide, Design Guide, Operational Guide and User Guide
• Scaffold handover certificate: When a scaffolding contractor erects and hands over a scaffold, they should issue a scaffold handover certificate (Scaffold Tag Certificate), confirming that the scaffold was erected to the specified design and is safe for use. This is the contractor's confirmation — it does not remove the duty to carry out weekly inspections
• NASC membership: Principal scaffolding contractors are typically NASC members — this provides a level of quality assurance. NASC members must follow TG20 and NASC guidance. Non-NASC contractors may still be competent, but check their qualifications carefully
• Exclusion zones: During scaffold erection, alteration and dismantling, exclusion zones must be established to prevent people being struck by falling materials. There is no single fixed multiple of the scaffold height in NASC guidance — the extent of the zone is determined by risk assessment for the specific job, following NASC SG4:22 (Preventing Falls in Scaffolding Operations) and SG34 (Protection of the Public)

Quick Reference Table

Detailed Guidance

TG20:21 — Standard vs Bespoke Scaffold

TG20:21 provides tables that define the maximum bay widths, maximum lift heights, maximum platform heights, and tie patterns for standard tube-and-fitting scaffold configurations. If the scaffold configuration is within TG20:21 limits, a competent scaffolding contractor can erect it without commissioning a separate structural design. TG20:21 tightened the detail on bracing, load calculations and stability compared with TG20:13, and NASC has since issued a technical update on baseplate practice.

Standard configurations covered by TG20:21:

• Independent scaffold (two rows of standards, boards spanning between ledgers)
• Putlog scaffold (one row of standards, putlog tubes embedded in masonry)
• Cantilever scaffold (limited cantilever from the face of the structure)
• Birdcage scaffold (internal scaffold for ceiling work)

When is a bespoke design needed?

• Scaffold exceeds TG20 height, bay width, or platform load tables
• Unusual loading (heavy materials, plant, multiple working levels)
• Adjacent to excavations (ground may be unstable)
• Cantilever balconies, projecting scaffold arms
• Historical or unusual structures where standard tie patterns cannot be used

Bespoke design process: A structural engineer or NASC member with design competence produces a scaffold design drawing and method statement. The drawing specifies standards, ledgers, ties, and bracing. The erecting contractor builds to the design and issues a handover certificate.

Carrying Out a Weekly Scaffold Inspection

The weekly inspection should be systematic — use a checklist to ensure nothing is missed. Walk the full perimeter of the scaffold and check every level:

Ground level:

• Base plates present under every standard (50×50mm minimum on soft ground: sole boards required — 225mm wide timber minimum)
• Standards plumb (visually — if in doubt, use a spirit level)
• No soil erosion under sole boards
• No vehicle damage to scaffold feet

Each lift (work level):

• All boards present, covering the full width of the working platform (minimum 600mm wide, 4 boards of 225mm each = 900mm — standard platform)
• Boards lapped at transoms (minimum 150mm lap, maximum 300mm overhang beyond transom)
• Board clips (over-edge restraint) or board stops fitted where boards could slide or tip
• Guard rails: top rail at least 950mm above the platform, intermediate rail set so no unprotected gap exceeds 470mm, toe board fitted (150mm is normal practice). No gaps in the guard rail system
• Ladders: tied at top, footed or pegged at bottom, extending 1050mm above the landing point, angle 1:4 (75°)

Ties (at each tie position):

• Check that ties are all still in place and tight. A tie removed for access must be replaced immediately or a temporary alternative provided
• Check that ties are into suitable fixings — not just pushing the scaffold into a window opening or tied to loose brickwork
• Tie density: typically every 4m vertically and every 6m horizontally for standard independent scaffold — confirm against the TG20:21 compliance sheet or the bespoke design

After adverse weather:

• Check for movement — has the scaffold shifted? Any standards out of plumb that were plumb before?
• Check for water damage to boards (swelling or deterioration)
• Check for wind damage to fans, debris netting, or sheeting

ScaffTag System

ScaffTag is a proprietary tagging system (green tag = safe to use, red tag = do not use) hung on the scaffold access point. The tag shows:

• The date of the last inspection
• The date the next inspection is due
• The name of the inspector
• Any restrictions on use (load limits, specific bays not in use)

ScaffTag provides an immediate visual confirmation that the scaffold has been inspected. However, the tag is NOT a substitute for the written inspection record — both are required.

If a scaffold is found to be unsafe during inspection, the tag must be changed to red (or removed) and the scaffold must be taken out of use immediately until the defect is remedied and a further inspection is carried out.

Scaffold Handover Certificate

When a scaffold contractor completes erection and hands the scaffold over to the principal contractor or client, they should provide a scaffold handover certificate. NASC SG35 — Handover of Scaffold Structures and First Scaffold Inspection is the guidance covering this. The certificate typically states:

• The scaffold was erected in accordance with TG20:21 / TG30:24 (or the specified bespoke design)
• The scaffold was inspected on handover and found to be safe
• The maximum permitted load per platform level
• Any restrictions on use
• The scaffolding contractor's name and CISRS card numbers

This certificate is the scaffolding contractor's sign-off — it confirms the scaffold as erected is safe. It does not transfer ongoing inspection responsibility to the scaffolding contractor — that remains with the person controlling the work.

Falls from Scaffold

The most common scaffold-related injury is a fall from an unguarded edge or through a missing board. The mandatory guard rail configuration (top rail at least 950mm, no unprotected gap over 470mm, toe board fitted) prevents most falls through the guard rail. However, common failures are:

• Gap in guard rail at access point — ladder access creates an opening. A self-closing gate or a removable section that must be replaced immediately is required
• Missing intermediate rail — installers often remove the mid rail to pass materials through and don't replace it
• Boards at edges not clipped — boards near the edge of a platform can slide inward, creating a gap

If any worker identifies a scaffold defect during use, they must report it immediately and stop work at that location until the defect is remedied. This is a duty on all workers under the Health and Safety at Work Act 1974 (HSWA).

Frequently Asked Questions

Who is responsible for scaffold inspection on a domestic job?

The person controlling the work. In a domestic refurbishment where a sole trader has hired a scaffolding contractor, the sole trader is responsible for weekly scaffold inspections once the scaffold has been handed over. The scaffolding contractor's handover certificate is not sufficient for ongoing inspection. The sole trader must carry out weekly checks and keep records, or appoint a competent person to do so.

Can I carry out my own scaffold inspections?

Yes — if you are a competent person. Competence for scaffold inspection means: sufficient knowledge and practical experience to identify structural faults, missing ties, overloading, and guard rail deficiencies. A CISRS scaffold inspection card is not legally required for the principal contractor's weekly inspection — but competence must be demonstrable. PASMA (Prefabricated Access Suppliers' and Manufacturers' Association) and CITB courses are available.

What happens if I work on scaffold that has not been inspected?

Working on uninspected scaffold is a breach of the Work at Height Regulations 2005. If an accident occurs, the Enforcement Authority (HSE) will investigate and may prosecute the person controlling the work, the scaffold contractor, and potentially the worker for failing to comply with safe working requirements. Fines are substantial, and for fatalities, criminal prosecution is common.

My scaffold contractor says TG20 doesn't apply to their scaffold — is this right?

Partly. TG20:21 applies to tube-and-fitting scaffold. System scaffold (Layher, Harsco, Plettac, Peri) is covered instead by NASC TG30:24, published November 2024 as the system-scaffold companion to TG20, or by the system manufacturer's own design guides. So "TG20 doesn't apply" is a valid answer only if they can point to TG30:24 compliance or the manufacturer's technical data confirming the configuration is within the design envelope. If they cannot provide either, insist on a bespoke structural design.

Regulations & Standards

• Work at Height Regulations 2005 (SI 2005/735) — Regulation 12: inspection of work equipment used at height. Schedule 7: matters to be included in a scaffold inspection report

• CDM Regulations 2015 — Duty on principal contractor to ensure scaffold inspected

• TG20:21 — NASC guide for tube-and-fitting scaffold design and erection (replaced TG20:13 in 2021)

• TG30:24 — NASC guide for system scaffolding (published November 2024)

• BS EN 12811-1:2003 — Temporary works equipment: scaffolding performance requirements and general design

• NASC SG4:22 — Preventing Falls in Scaffolding Operations — the Scaffolders' Safe Zone method for erection, alteration and dismantling (replaced SG4:15)

• NASC SG35 — Handover of Scaffold Structures and First Scaffold Inspection — NASC guidance for scaffold handover certificates

• NASC SG34 — Protection of the Public — exclusion zones, fans, netting and public protection

• NASC (National Access and Scaffolding Confederation) — TG20:21 and TG30:24 eGuides, SG series guidance, and member directory

• HSE — Working at Height in Construction — Regulatory guidance on scaffold inspection requirements

• PASMA — Scaffold Safety — Training courses for scaffold inspection and use

• working at height — Work at Height Regulations overview and ladder safety

• re roofing — Scaffold requirements for re-roofing

• cdm regulations — CDM 2015 duties for scaffold on notifiable projects

• method statements — Method statement requirements for scaffold erection