ScaFixShort answer
How many guardrails and toe boards does a scaffold need?
Three numbers decide it: how many bays the run takes, how many lifts are boarded, and whether the system's side protection is one double guardrail per bay or a separate main rail and intermediate rail. The ends and the base lift come on top, and they are what a quick count tends to miss.
By Ole Emil Frikstad Urstad · Checked against Work at Height Regulations 2005, Schedule 2, paragraphs 3 and 5; 29 CFR 1926.451, (g)(4), (h)(2), (h)(4) (25 October 2026) · How the numbers are computed ·
How many guardrails and toe boards go on one bay?
Each boarded bay takes one toe board and a main guardrail with an intermediate rail: one piece in frame systems like HAKI Universal, two rails in tube and fitting, Kwikstage and Cuplok. Every boarded lift also needs an end guardrail at each open end. In the UK the top rail is at least 950 mm high (WAHR Schedule 2).
Before you rely on this guide
This guide summarises published rules to help you plan and is not legal advice. It has not been reviewed by a qualified scaffold designer or engineer. ScaFix is a planning aid, not structural approval: the manufacturer's instructions, the scaffold design and a competent person's inspection decide what is built and used on site.
How do you work out guardrails and toe boards for a run?
Multiply the bays by the boarded lifts and by the guardrail pieces per bay: one where a frame or double guardrail carries both rails, two where the main and intermediate rails are separate tubes or ledgers. Add two end guardrails per boarded lift and the rails of the base lift. Toe boards are bays times boarded lifts in every system.
- Bays: a 20 m run takes 9 bays in tube and fitting (5 × 2.4 m + 4 × 2 m) and 7 in Kwikstage (4 × 3.05 m + 3 × 2.44 m).
- Boarded lifts: on an 8 m elevation ScaFix boards the lifts at 2.6, 4.6 and 6.6 m, so 3 working lifts. The top lift above them carries the guardrail only.
- Guardrails on the face: bays × boarded lifts × pieces per bay. Tube and fitting: 9 × 3 × 2 = 54. HAKI Universal: 7 × 3 × 1 = 21.
- Base lift: the rails in the bottom lift, which carry no boards: 18 in tube and fitting and 7 in HAKI Universal on this run.
- Ends: 2 end guardrails per boarded lift, 6 in all.
- Toe boards: 9 bays × 3 lifts = 27.
What does a 20 m run with 3 boarded lifts need?
ScaFix's engine counts between 28 and 72 guardrail pieces on the face of the same 20 m × 8 m run, depending on the system. Most of the gap is one piece per bay against two; the shorter 2.4 m and 2.0 m tube bays add more. Toe boards and end guardrails follow the bays and lifts only.
| System | Bays | Guardrail pieces per bay and lift | Guardrail pieces, face total | End guardrails | Toe boards |
|---|---|---|---|---|---|
| Tube and fitting | 9 (5 × 2.4 m + 4 × 2 m) | 2 | 72 | 6 | 27 |
| Kwikstage | 7 (4 × 3.05 m + 3 × 2.44 m) | 2 | 56 | 6 | 21 |
| SGB Cuplok | 7 (5 × 3 m + 2 × 2.5 m) | 2 | 56 | 6 | 21 |
| Layher Allround | 7 (7 × 3.07 m) | 2 | 56 | 6 | 21 |
| HAKI Universal | 7 (7 × 3.05 m) | 1 | 28 | 6 | 21 |
| Layher Blitz | 7 (7 × 3.07 m) | 1 | 28 | 8 | 28 |
| Waco frame (US) | 7 (6 × 3.05 m + 1.52 m) | 1 | 28 | 6 | 21 |
The face total includes the base lift. Figures are for one straight run boarded on the outside with a ladder bay; returns and corners add bays of their own, counted in the corners guide.
Why does the base lift get guardrails with no boards?
Because the rails stiffen the scaffold as well as guard it. HAKI's manual allows guardrail frames to replace the vertical diagonal braces, but only if they are fitted in every bay and at every lift level, including the bottom level (HAKI, p. 32). A base lift left without them loses that stiffening even though nobody stands on it.
ScaFix therefore puts the rail set in the bottom lift of every facade system, on the outside, whether or not that lift is boarded. On this run it is 18 of the 72 tube-and-fitting rails. Leave them off the order and the scaffold arrives short of the members that hold its base in line.
What do the UK rules say about rails and toe boards?
For construction work, Schedule 2 of the Work at Height Regulations 2005 requires a top guard-rail at least 950 mm above the edge, toe-boards suitable and sufficient to stop people or materials falling, and an intermediate guard-rail placed so that no gap exceeds 470 mm. Openings are allowed only at a ladder or stair access point.
The schedule sets what each rail must do, not how many you need; the count comes from the bays and lifts above. Heights are covered in detail in the scaffold guardrail height guide.
What does OSHA require on US scaffolds?
Under 29 CFR 1926.451(g)(4) guardrail systems go along all open sides and ends of platforms, with the top rail 38–45 in (0.97–1.14 m) above the platform on supported scaffolds placed in service after 1 January 2000 and midrails about halfway. Where tools could fall on people below, (h)(2) calls for toeboards on platforms over 10 ft (3.05 m) high.
Toeboards, where used, must be at least 3.5 in (8.9 cm) high under (h)(4). The rule on ends is why the end guardrail column in the table is never zero once a lift is boarded: an open end is a platform edge like the face. US frame systems such as Waco count one guardrail piece per bay in ScaFix, the same as other frame systems.
Planning information, not structural approval. Guardrails, toe boards and bracing follow the manufacturer's instructions or a design (TG20:21 in the UK), and a competent person inspects the scaffold before use.
Frequently asked questions
How many toe boards does a scaffold need?
One per bay and boarded lift on the outside, plus end toe boards where a lift ends. A 20 m × 8 m tube-and-fitting run takes 9 bays × 3 lifts = 27 toe boards.
Does the top lift need a toe board?
Yes, the top boarded lift is a working platform like the others. Only the guardrail lift above it, which has no boards, has no toe board.
Is a double guardrail one rail or two?
One component that gives both the main rail and the intermediate rail. Tube and fitting, Kwikstage and Cuplok use two separate members per bay and lift instead.
How high must a toe board be in the US?
At least 3.5 in (8.9 cm) from the top edge of the toeboard to the platform, under 29 CFR 1926.451(h)(4).
Sources
Primary sources used for this article, with the date each was read.
- Work at Height Regulations 2005, Schedule 2 (guard-rails, toe-boards, barriers) (read 25 October 2026)
- 29 CFR 1926.451 General requirements for scaffolds, (g)(4) guardrails and (h)(2) toeboards (LII, Cornell) (read 25 October 2026)
- HAKI Universal user's manual, international version (© HAKI AB 2024): inside board brackets p. 17–19, guardrails and toe boards p. 29, bracket load classes p. 30, bracing and tying-in p. 32 (pdf) (read 25 October 2026)
- Layher Allround Scaffolding, Instructions for Assembly and Use, edition 04.2018: §2.2 side protection (PDF p. 11), §4.8 toe board (p. 20), §5 facade scaffolding step 7 (p. 22), §16 brackets (p. 44), §18 brick guard (p. 48) (read 25 October 2026)
- SGB CUPLOK User Manual, UK version (Brand Energy & Infrastructure Services UK): bracing p. 29 and p. 31 (pdf) (read 25 October 2026)
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