Scaffold load classes and width classes explained

What does the EN 12811-1 load class table say?

The six classes are defined in EN 12811-1, the European design standard for working scaffolds. The standard itself is sold by the national standards bodies, but regulators reproduce the table. The clearest public copy is section 4-2 of the Norwegian Producer Responsibility Regulations, which gives every value in kN and in kilograms. The German DGUV Information 201-011 prints the same distributed and partial-area loads.

The values are EN 12811-1's Table 3 (service loads on working areas). A is the deck area between two pairs of standards, in other words one bay. The partial-area load lets a class 4–6 scaffold carry a heavier stack on part of the bay, as long as the rest of the bay carries correspondingly less.

Four load cases, not one number

People quote the first column, but a deck has to pass all four checks. The concentrated loads matter for narrow boards: a single 0.32 m steel plank in a class 3 bay must hold 1.5 kN on a 500 mm square and a person standing on a 200 mm square, not just 2.0 kN spread over its area.

Which work fits which load class?

The standard defines loads, not trades. National guidance translates them. DGUV Information 201-011, section 6.1.2, is the most specific public text:

• Class 1: inspection only, such as reading, looking and function checks.
• Class 2: work that needs no storage of building materials or components.
• Class 3: work where people plus materials stay within 2.0 kN/m². Its example is class 3 with width class W06 for plastering, roofing, painting and facade cladding.
• Classes 4–6: work where materials or components are set down or stored on the deck, and then at least width class W09. Its example is class 4 with W09 for masonry, reinforcement, tiling, natural stone and assembly work.

The same section counts each person as 1 kN, multiplies loads set down by a hoist by 1.2 and requires a protective (catch) scaffold to be at least class 2. Danish guidance went further: under the Danish Working Environment Authority's scaffold erector guidance, since withdrawn (the authority replaced about 180 guidance notes with far fewer from 15 December 2025, according to DI), scaffolds in classes 1 and 2 were in practice only fit for inspection.

What are width classes W06 to W24?

Width classes describe the clear width of the working deck, including the toe board (counted as at most 30 mm, according to Baunetz Wissen).

Facade systems with a system width of about 0.7 m, such as the Layher Blitz 70 (0.732 m) or the aluminium system certified as SW06 below, give a W06 deck. Former Danish guidance noted that a wider class can be reached by laying several decks side by side on the same level, and it asked for at least W12 for sandblasting and window fitting so workers have room for tools and trolleys.

Headroom classes H1 and H2

The headroom class describes the clear passage height inside the frame, and EN 12811-1 sets it in its Table 2 (Table 1 holds the width classes). As Baunetz Wissen puts it, a frame with less than 1.90 m of clear headroom is H1, and one with 1.90 m or more is H2. Baunetz adds that because system scaffolds dominate in Germany, H1 is the class normally used there; the Norwegian SINTEF certificate quoted below, by contrast, is H2. In both classes the clear height between decks must be at least 1.90 m.

Why does the same scaffold reach different classes?

Because the class belongs to a configuration, not to a brand. Bay length, deck type and the number of loaded lifts all change it, and the manufacturer's approval tells you which combinations were proven. Two German approvals from the Deutsches Institut für Bautechnik (DIBt) show it clearly.

The Layher Blitz 70 Steel approval Z-8.1-16.2, issued 2 January 2025 and valid to 4 January 2030, lists in Table 6 the class each deck reaches at each bay length:

The same approval describes the standard configuration (Regelausführung) as a facade scaffold up to 24 m with a system width of 0.732 m and bays of at most 3.07 m for load class 3. A deck rated class 4 therefore does not make the whole scaffold class 4: frames, ties and base plates were only proven for class 3 in that standard set-up, and anything else needs its own calculation.

The PERI UP Easy approval Z-8.1-957 shows the same pattern for its EDS 33 steel deck in the modular build: a 3.0 m bay is valid up to class 4, a 2.5 m bay up to class 5 and a bay of 2.0 m or less up to class 6.

What does «class 3 / W06» on a scaffold tag mean?

On site you usually see two numbers on the tag: the load class and the width class. Class 3 / W06 means each bay may carry 2.0 kN/m² across the decks within it and the deck is 0.6 to 0.9 m wide. It does not mean every lift may carry 2.0 kN/m² at the same time. DGUV states that the sum of the distributed loads on the decks within one bay must not exceed the class value, and Danish guidance described the usual system rule as one lift at 100 % and one at 50 %, with the others unloaded.

The product label on the frames uses the longer EN 12810-1 designation. The Norwegian SINTEF certificate for one aluminium system reads EN 12810-3N-SW06/305-H2-A-LA: load class 3, «N» for no drop test on the deck, system width class 06 with a 3.05 m bay, headroom H2, «A» for unclad and «LA» for ladder access. Baunetz Wissen decodes the same pattern: «D» means the deck passed a drop test, «B» means cladding is allowed, «ST» means stair access and «LS» both.

Light, medium and heavy duty: how do UK and US rules rate scaffolds?

In Great Britain the Work at Height Regulations 2005, Schedule 3 Part 2, require strength and stability calculations unless the scaffold follows a generally recognised standard configuration (paragraph 7), and decks that are «suitable for the loads to be carried» (paragraph 10). For tube-and-fitting work that standard configuration is usually a TG20 compliance sheet; the NASC launched TG20:21 as an online e-guide in April 2021, built around BS EN 12811. System scaffolds follow the manufacturer's approval, as above. The wider rule sets are summarised in UK scaffolding regulations and TG20 and OSHA scaffolding requirements, and other countries in scaffolding regulations by country.

In the United States, 29 CFR 1926.451(a)(1) requires each scaffold to support its own weight and at least four times the maximum intended load, and (f)(1) forbids loading beyond rated capacity. The non-mandatory Appendix A names three duty ratings: light duty 25 lb/ft², medium duty 50 lb/ft² and heavy duty 75 lb/ft², each applied over the whole span. Converted, that is roughly 1.2, 2.4 and 3.6 kN/m²; they are not the same thing as EN classes, so never treat «medium duty» as «class 3».

What are the most common load class mistakes?

1. Treating «medium duty» as class 3. OSHA's Appendix A ratings (25, 50 and 75 lb/ft²) are a separate scheme from the EN classes; check the manufacturer's US data on a US job and its EU data on a European one.
2. Loading past the rated capacity. 29 CFR 1926.451(f)(1) forbids it outright, and the fourfold rule in (a)(1) is a design margin, not spare capacity for an extra pallet.
3. Building outside the compliance sheet without a calculation. Once a tube-and-fitting scaffold leaves its TG20 configuration, Schedule 3 paragraph 7 of the Work at Height Regulations 2005 calls for strength and stability calculations.
4. Reading the deck rating as the scaffold rating. In the Layher approval above a steel deck reaches class 4 at 3.07 m while the standard configuration is class 3, so a class 4 or 5 masonry job is planned with shorter bays from the start.

For the checks on site, see the scaffold inspection checklist, and for the scaffold families these classes apply to, types of scaffolding. ScaFix lays out the bay lengths each of its scaffold systems offers, so switching a masonry run to shorter bays shows up at once in the model and parts count, but it never assigns or approves a load class; the methodology page lists what it checks.

This is planning information, not structural approval. The class a scaffold may carry comes from the manufacturer's approval and instructions for the configuration actually built. In Great Britain, Schedule 3 of the Work at Height Regulations 2005 calls for a calculation outside a recognised standard configuration such as TG20; in the US, 29 CFR 1926.451 makes a competent person responsible. Either way, a competent person must inspect the scaffold and record its class before anyone loads it.

Frequently asked questions

Sources

Primary sources used for this article, with the date each was read.

• Arbeidstilsynet: Producer Responsibility Regulations, section 4-2 (load classes) (read 23 October 2026)
• DGUV Information 201-011, Abschnitt 6 Technisches Wissen (Breiten- und Lastklassen) (read 23 October 2026)
• DIBt Z-8.1-16.2: Layher Blitz Gerüst 70 Stahl (Bescheid vom 2. Januar 2025) (read 23 October 2026)
• DIBt Z-8.1-957: PERI UP Easy (Ergänzungsbescheid vom 12. Mai 2025) (read 23 October 2026)
• SINTEF Produktsertifikat nr. 3535: Alusafe Stillas kl. 3 (read 23 October 2026)
• Baunetz Wissen: Gerüstklassen (read 23 October 2026)
• Baunetz Wissen: Gerüstbezeichnung nach DIN (read 23 October 2026)
• Retsinformation: At-vejledning 45.1 om stilladsopstillerens ansvar (VEJ nr. 9694 af 28/06/2015) (read 23 October 2026)
• DI: 180 vejledninger bliver til 25 (17.12.2025) (read 23 October 2026)
• Work at Height Regulations 2005, Schedule 3 Part 2 (scaffolding) (read 23 October 2026)
• Scaffmag: NASC TG20:21 scaffolding guidance launched (12 April 2021) (read 23 October 2026)
• 29 CFR 1926.451: General requirements for scaffolds (read 23 October 2026)
• 29 CFR 1926 Subpart L, Appendix A: Scaffold Specifications (read 23 October 2026)