1926.451(b): Scaffold platform planking and width
Each scaffold working platform must be fully planked or decked between the front uprights and the guardrail supports, with no more than 1 inch between planks or between the platform and the uprights unless a wider gap is shown to be necessary (and then no more than 9 1/2 inches). Full planking is not required on platforms used only as walkways or only by erectors and dismantlers. Platforms and walkways must generally be at least 18 inches wide, with exceptions for certain scaffold types.
Key takeaways
- 1926.451(b) is part of OSHA's construction standards (29 CFR Part 1926, Subpart L).
- OSHA cited it 1,518 times in the last 3 years, in 1,325 inspections, with $4,859,098 in current penalties.
- 17 deaths are linked to inspections that cited this rule.
- Most citations: TX (156), FL (118), NC (103).
- Related part: 1926.451(b)(1) (870 citations).
- Free 5-minute toolbox talk for your crew below.
In this article
What this rule covers
29 CFR 1926.451(b) ("Scaffold platform construction") is one requirement inside 1926.451 General requirements, an OSHA construction standard (Part 1926, Subpart L). It includes 19 sub-paragraphs. The official text below is copied word for word from the Electronic Code of Federal Regulations (eCFR). The numbers, injury cases and training on this page show how OSHA enforces it on real job sites.
Official text
(b) Scaffold platform construction. 1,518 citations
(1) Each platform on all working levels of scaffolds shall be fully planked or decked between the front uprights and the guardrail supports as follows: Open (b)(1) 870 citations
(i) Each platform unit (e.g., scaffold plank, fabricated plank, fabricated deck, or fabricated platform) shall be installed so that the space between adjacent units and the space between the platform and the uprights is no more than 1 inch (2.5 cm) wide, except where the employer can demonstrate that a wider space is necessary (for example, to fit around uprights when side brackets are used to extend the width of the platform). Open (b)(1)(i) 168 citations
(ii) Where the employer makes the demonstration provided for in paragraph (b)(1)(i) of this section, the platform shall be planked or decked as fully as possible and the remaining open space between the platform and the uprights shall not exceed 91⁄2 inches (24.1 cm). Open (b)(1)(ii) 14 citations
Exception to paragraph (b)(1): The requirement in paragraph (b)(1) to provide full planking or decking does not apply to platforms used solely as walkways or solely by employees performing scaffold erection or dismantling. In these situations, only the planking that the employer establishes is necessary to provide safe working conditions is required.
(2) Except as provided in paragraphs (b)(2)(i) and (b)(2)(ii) of this section, each scaffold platform and walkway shall be at least 18 inches (46 cm) wide. Open (b)(2) 332 citations
(i) Each ladder jack scaffold, top plate bracket scaffold, roof bracket scaffold, and pump jack scaffold shall be at least 12 inches (30 cm) wide. There is no minimum width requirement for boatswains' chairs. Open (b)(2)(i) 11 citations
Pursuant to an administrative stay effective November 29, 1996 and published in the Federal Register on November 25, 1996, the requirement in paragraph (b)(2)(i) that roof bracket scaffolds be at least 12 inches wide is stayed until November 25, 1997 or until rulemaking regarding the minimum width of roof bracket scaffolds has been completed, whichever is later.
(ii) Where scaffolds must be used in areas that the employer can demonstrate are so narrow that platforms and walkways cannot be at least 18 inches (46 cm) wide, such platforms and walkways shall be as wide as feasible, and employees on those platforms and walkways shall be protected from fall hazards by the use of guardrails and/or personal fall arrest systems. Open (b)(2)(ii) 7 citations
(3) Except as provided in paragraphs (b)(3) (i) and (ii) of this section, the front edge of all platforms shall not be more than 14 inches (36 cm) from the face of the work, unless guardrail systems are erected along the front edge and/or personal fall arrest systems are used in accordance with paragraph (g) of this section to protect employees from falling. Open (b)(3) 58 citations
(i) The maximum distance from the face for outrigger scaffolds shall be 3 inches (8 cm); Open (b)(3)(i) 1 citations
(ii) The maximum distance from the face for plastering and lathing operations shall be 18 inches (46 cm). Open (b)(3)(ii) 1 citations
(4) Each end of a platform, unless cleated or otherwise restrained by hooks or equivalent means, shall extend over the centerline of its support at least 6 inches (15 cm). Open (b)(4) 49 citations
(5) Open (b)(5) 118 citations
(i) Each end of a platform 10 feet or less in length shall not extend over its support more than 12 inches (30 cm) unless the platform is designed and installed so that the cantilevered portion of the platform is able to support employees and/or materials without tipping, or has guardrails which block employee access to the cantilevered end. Open (b)(5)(i) 21 citations
(ii) Each platform greater than 10 feet in length shall not extend over its support more than 18 inches (46 cm), unless it is designed and installed so that the cantilevered portion of the platform is able to support employees without tipping, or has guardrails which block employee access to the cantilevered end. Open (b)(5)(ii) 97 citations
(6) On scaffolds where scaffold planks are abutted to create a long platform, each abutted end shall rest on a separate support surface. This provision does not preclude the use of common support members, such as “T” sections, to support abutting planks, or hook on platforms designed to rest on common supports. 4 citations
(7) On scaffolds where platforms are overlapped to create a long platform, the overlap shall occur only over supports, and shall not be less than 12 inches (30 cm) unless the platforms are nailed together or otherwise restrained to prevent movement. Open (b)(7) 51 citations
(8) At all points of a scaffold where the platform changes direction, such as turning a corner, any platform that rests on a bearer at an angle other than a right angle shall be laid first, and platforms which rest at right angles over the same bearer shall be laid second, on top of the first platform. Open (b)(8) 9 citations
(9) Wood platforms shall not be covered with opaque finishes, except that platform edges may be covered or marked for identification. Platforms may be coated periodically with wood preservatives, fire-retardant finishes, and slip-resistant finishes; however, the coating may not obscure the top or bottom wood surfaces. Open (b)(9) 2 citations
(10) Scaffold components manufactured by different manufacturers shall not be intermixed unless the components fit together without force and the scaffold's structural integrity is maintained by the user. Scaffold components manufactured by different manufacturers shall not be modified in order to intermix them unless a competent person determines the resulting scaffold is structurally sound. Open (b)(10) 25 citations
(11) Scaffold components made of dissimilar metals shall not be used together unless a competent person has determined that galvanic action will not reduce the strength of any component to a level below that required by paragraph (a)(1) of this section.
Source: eCFR, text current as of 2026-10-15. Read all of 1926.451.
Injuries linked to this rule
17 deaths are linked to inspections where OSHA cited 1926.451(b).
Employee was removing a gutter from a residential structure working from a pump-jack scaffold system erected 4.5 feet from a 79 kilovolt primary power line. The gutter contacted the power line and the employee was electrocuted.
Full case list with employer, penalty, filters and download is part of OSHA Data (Purple Belt).
Unlock with Purple BeltWhere and how often it was cited
| Year | Citations |
|---|---|
| 2023 | 129 |
| 2024 | 486 |
| 2025 | 569 |
| 2026 | 334 |
Top states: TX (156), FL (118), NC (103), NY (95), VA (92)
Largest penalties
| Employer | Location | Penalty for this rule |
|---|---|---|
| THOMAS BUILDERS OF VIRGINIA, INC. | DALEVILLE, VA | $307,480 |
| THOMAS BUILDERS OF VIRGINIA, INC. | ROANOKE, VA | $130,000 |
| JOSE CALLE | PHILADELPHIA, PA | $82,757 |
| FINCANTIERI MARINE GROUP, LLC | STURGEON BAY, WI | $59,115 |
| JOSE CALLE | HATBORO, PA | $39,723 |
Free toolbox talk
A 5-minute crew talk on 1926.451(b), plus alerts when this rule changes. Free.
OSHA interpretation letters
- Whether #9 wire may be used to secure the toprails and midrails on tubular scaffolding; permissible method for setting transitional wood planks. (2010-04-30)
- Whether guardrails are required on a two-point adjustable scaffold while workers who are tied off are painting the undercarriage of a water storage tank. (2010-03-03)
- Fully Planked and Decked Scaffold (2010-03-02)
- Guardrail requirements for two point suspension scaffolds. (2006-09-14)
- Whether plywood may be used as scaffold decking material over wood scaffold planks; 29 CFR 1926.450 and 1926.451. (2006-05-18)
- Walkways within scaffolds, guardrails, and planking. (2005-07-26)
- Whether it is permissible to use a concrete block hanging on a coupling pin as a counterweight to prevent a scaffold from tipping. (2005-06-17)
- Use of 2"x6" No 2 pine boards as a scaffold platform; application of 1926.451(a) and 1926.451(f)(16) when erecting and dismantling scaffolds. (2005-04-11)
- Requirements in 1926 Subpart L "Scaffolds" regarding the use of plywood to make platform decking for scaffolds. (2004-06-21)
- Wire rope clips on suspension scaffolds; safety latches on large crane hooks; order of assembly for hanging scaffolds; and horizontal lifeline design. (2004-03-04)
- Storage of materials that prevents inspection of scaffolds before workshifts; incidental storage amounts that do not inhibit scaffold inspection. (2003-06-10)
- Use of aerial lift or scissor lift guardrails as a work or scaffold platform. (2002-10-23)
- Planking, safety line, and personal fall arrest system requirements for tank builder's scaffolding. (2002-04-16)
- Request that OSHA adopt a requirement that all scaffold planks meet a "scaffold grade" under recognized grading rules. (2002-03-12)
- Clarification of requirements for construction scaffold erection/dismantling; safe means of access; blocks for two-point suspension scaffolds. (2002-01-02)
- Exemptions for installation of guardrails on wall (interior) side. (2001-12-11)
- Requirements of Interim Fall Protection Compliance Guidelines for Residential Construction for guardrails and fall protection during roofing work. (2001-04-10)
- Requirements for scaffold grade lumber; qualifications of qualified/competent persons for grading scaffold lumber. (2001-02-16)
- Application of 1926.451(b)(3)(ii) to "Drivit" (synthetic stucco) systems. (2001-01-22)
- Overlapping of scaffold planking. (1999-02-07)
- Waler (platform) covered by Subpart L; minimum scaffold platform width. (1998-04-20)
- Minimum width of roof bracket scaffolds. (1996-12-12)
- Application for permanent variance from 1926.451(a)(4) and 1926.451(b)(11) (1989-12-01)
Related parts of this rule
- 1926.451(b)(1) 870 citations
- 1926.451(b)(2) 332 citations
- 1926.451(b)(1)(i) 168 citations
- 1926.451(b)(5) 118 citations
- 1926.451(b)(5)(ii) 97 citations
- 1926.451(b)(3) 58 citations
- 1926.451(b)(7) 51 citations
- 1926.451(b)(4) 49 citations
- 1926.451(b)(10) 25 citations
- 1926.451(b)(5)(i) 21 citations
- 1926.451(b)(1)(ii) 14 citations
- 1926.451(b)(2)(i) 11 citations
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Frequently asked questions
How big can the gap between scaffold planks be?
No more than 1 inch, unless the employer can show a wider space is necessary; then the platform is planked as fully as possible and the open space to the uprights may not exceed 9 1/2 inches.
How wide must a scaffold platform be?
At least 18 inches, except for the scaffold types listed in paragraphs (b)(2)(i) and (ii).
About this page
Sources
- 29 CFR 1926.451 (eCFR), text current as of 2026-10-15
- U.S. Department of Labor enforcement data: OSHA inspections, citations and accident records, copied nightly; data as of 2026-10-19
3-year window. Federal OSHA only; state-plan rules are not counted. Plain-language text is a summary, not legal advice; the official text controls. Black Belt Safety is not part of OSHA or the Department of Labor.
