512 EM 385-1-1 Chapters 16-22

Sections

22-8. General Requirements.

General Guidelines for Work Platforms and Scaffolding

Select work platforms like scaffolds or temporary floors unless it's safe to work from the ground or a similar surface.
Avoid the use of ladder jacks, lean-to, prop-scaffolds, and emergency descent devices as work platforms.
Ensure work platforms or scaffolds are not erected near power lines or during adverse weather conditions like storms or high winds.

Access and Fall Protection

Standard railings and handrails must meet the specifications outlined in chapter 24.
Guardrails must conform to the requirements in chapter 21, and cross bracing can be used as part of guardrail systems under specific conditions.
Cross bracing is acceptable as a toprail of a guardrail system when the crossing point of two braces is between 38 inches and 48 inches above the work platform.
Cross bracing is not permitted to serve as both a midrail and top rail of a guardrail system.

Scaffolds: General Requirements

The erection, movement, dismantling, or alteration of scaffolding must be supervised by a Competent Person (CP) for Scaffolding.
Conduct inspections as directed in paragraph 22-5 and ensure proper load capacities according to ANSI A10.8 standards.
Design and construct scaffolds following ANSI A10.8 standards, ensuring materials meet specified requirements and wind calculations are performed for wrapped scaffolds.

Scaffold Construction and Safety

Ensure scaffold foundations are stable, and vertical members are plumbed and braced to prevent swaying or displacement.
Scaffolds must be level and plumb, bear on adequate foundations, and have fully planked or decked working levels.
Adhere to specific regulations for scaffold planking, including lumber quality, maximum span lengths, and proper installation to prevent displacement or tipping.

Scaffold Access and Stability

Provide safe scaffold access and ensure built-in ladders meet the ladder requirements in chapter 24.
Secure scaffolds to structures when height exceeds four times the base dimension, following specific requirements for vertical and horizontal ties.
When scaffolds are enclosed or in proximity to vehicles, ensure proper measures like ground guides or barricades are in place for safety.

Special Scaffold Types and Approvals

Design and construct special scaffolds like outrigger and needle-beam scaffolds according to ANSI A10.8 standards.
For scaffold types not covered by ANSI A10.8, obtain design approval from a Registered Professional Engineer (RPE) or ensure compliance with a recognized national standard.
Use brackets on scaffolds only if the tipping effect is adequately controlled.

Knowledge Check Choose the best answer for the question.

22-6. The crossing points of cross bracing must be _____ above the work platform.

43 inches

38 inches to 48 inches

at least 48 inches

40 inches to 46 inches

You forgot to answer the question!

EM 385-1-1 Paragraph 22-8 (a.–c.).

22-8. General Requirements. (a.–c.).

a.  General. This chapter establishes safety requirements for the construction, operation, maintenance, and use of work platforms and scaffolding used in construction, alteration, demolition, operations, and maintenance of buildings and other structures.  It does not apply to permanently installed platforms.  (22-8.a)

(1)  Comply with the following hierarchy and prohibitions when selecting an appropriate work platform:

(a)  Only perform work using scaffolds, platforms, or temporary floors unless if the work cannot be safely performed from the ground or similar footing.

(b)  Ladders may be used as work platforms only when allowed by manufacturer.

(d)  Do not use emergency descent devices as working platforms (see chapter 19).

(2)  Do not erect or use work platforms or scaffolds in the immediate vicinity of power lines or electrical conductors until such are insulated, de-energized, or otherwise rendered safe from accidental contact (see chapter 11).

(3)  Do not work on scaffolds during storms, high winds, or other adverse weather conditions.

b. Access and Fall Protection.  (22-8.b)

(1)  Standard railings and handrails for stairs must comply with the requirements of chapter 24.

(2)  Standard guardrails must comply with chapter 21.

(3)  Scaffold Cross Bracing.

(a)  Cross bracing is acceptable in place of a midrail of a guardrail system when the crossing point of two braces is between 20 inches (0.5 m) and 30 inches (0.8 m) above the work platform.

(b)  Cross bracing is acceptable as a toprail of a guardrail system when the crossing point of two braces is between 38 inches (96.5 cm) and 48 inches (121.9 cm) above the work platform.

(d)  Cross bracing cannot be used for both a midrail and top rail.

c.  Scaffolds (excludes MEWPs).  General requirements for all scaffolds.  (22-8.c)

(1)  Erection, moving, dismantling, or altering of scaffolding must be under the
    supervision of a CP for Scaffolding.

(2)  Perform inspections according to paragraph 22-5.

(3)  Where persons are required to work or pass under a scaffold, provide a screen (consisting of No. 18 gauge US Standard wire one-half (½) inch (1.3 cm) mesh or the equivalent) between the toe-board and the guardrail and extend over the entire opening, or restrict access to the potential impact area below.

(4)  Capacities.

(a)  Scaffolds and their components must meet the requirements contained in ANSI A10.8 or other applicable ANSI standard and be capable of supporting without failure at least 4 times the maximum anticipated load.

(b)  Direct connections to roofs and floors and counterweights used to balance adjustable suspension scaffolds must be capable of resisting at least 4 times the tipping moment imposed by the scaffold operating at the rated load of the hoist, or 1.5 times (minimum) the tipping moment imposed by the scaffold operating at the stall load of the hoist, whichever is greater.

(5)  Design.

(a)  The dimensions of the members and materials used in the construction of various working platforms or scaffolds must conform to the sizes shown in the ANSI A10.8 tables.

(b)  Factory-fabricated scaffolds and components must be designed and fabricated according to the applicable ANSI standard.  When there is a conflict between the ANSI standard and this manual concerning the design or fabrication of factory-fabricated scaffolds, the ANSI standard will prevail.

(c)  Load-carrying timber members must be a minimum of 1,500 lb-f/in2 (10,342 kPa) (stress grade) construction grade lumber.

(c-1)  All dimensions are nominal sizes (except where rough sizes are noted)
            according to Voluntary Product Standard DOC PS20.

(c-2)  Where rough sizes are noted, only rough or undressed lumber of the size specified will satisfy minimum requirements.

(c-3)  Lumber must be reasonably straight-grained and free of shakes, checks, splits, cross grains, unsound knots or knots in groups, decay and growth characteristics, or any other condition that will decrease the strength of the material (see para 22-8.c).

(d)  When scaffolds are wrapped with tarps, poly enclosures, or similar materials, wind calculations must be calculated by a QP to determine the strength and placement of the ties.

(6)  Supporting members and foundations must be of sufficient size and strength to safely distribute loading.

(a)  Place supporting members on a firm, smooth foundation that will prevent lateral displacement.

(b)  Do not use unstable objects such as barrels, boxes, loose bricks, or concrete blocks as supports.

(7)  Design and construct or select solid wood planking and platform for means of access based upon either the number of persons for which they are rated or the uniform load distribution to which they will be subjected, whichever is the more restrictive.

(8)  Scaffolds must be plumb and level unless engineered and designed to contour as the structure does.

(9)  Scaffolds (other than suspended scaffolds) must bear on base plates upon mudsills or other adequate firm foundation.

(10)  Working levels of work platforms must be fully planked or decked.

(11)  Planking.

(a) All wood planking selected for scaffold plank use must be recognized by grading rules established by a recognized independent inspection agency for the species of wood used.

(b)  Do not exceed spans of 8 feet (2.4 m) for 2 inches x 10 inches
        (5.1 cm x 25.4 cm) (nominal), or 10 feet (3 m) for 2 inches x 9 inches (5.1 cm x 22.9 cm) (rough) solid sawn wood planks.

(c)  Fabricated planks and platforms may be used in lieu of solid sawn wood planks. Adhere to maximum spans according to the manufacturer’s instructions.

(d)  Secure planking to prevent loosening, tipping, or displacement, and support or brace to prevent excessive spring or deflection.  Use intermediate beams to prevent dislodgement of planks due to deflection.

(e)  Fully plank or deck each platform on all working levels of scaffolds between the front uprights and the guardrail supports as follows:

(e-1)  Install each platform unit (for example, scaffold plank, fabricated plank, fabricated deck, or fabricated platform) 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).

(e-2)  Where the employer makes the demonstration as described above, the platform must be planked or decked as fully as possible and the remaining open space between the platform and the uprights must not exceed 9.5 inches (24.1 cm).

(f)  When planking is lapped in a long run, lap each plank at its supports at least
        12 inches (30.5 cm). Extend scaffold planks over the end supports at least 6 inches (15.2 cm) (unless the planking is manufactured with restraining hooks or equivalent means of preventing movement), but not more than 12 inches (30.5 cm).  Lap or securely fasten work surfaces to the scaffold.

(g) Where the ends of planks abut each other to form a flush floor, position the butt joint at the centerline of a pole so that abutted ends rest on separate bearers.

(h)  Position the front edge of all platforms not more than 14 inches (36 cm) from the face of the work unless guardrail systems are erected along the front edge and/or PFAS are used; the maximum distance from the face for plastering and lathing operations is 18 inches (46 cm).

(i)  Support or brace planking to prevent excessive spring or deflection and secure and support to prevent loosening, tipping, or displacement.

(j)  When a scaffold materially changes its direction, lay the platform planks to prevent tipping according to the following:

(j-1)  Lay the planks that meet the corner bearer at an angle first (unless hook-on fabricated planks are used) and extend over the diagonally placed bearer far enough to have a good safe bearing, but not far enough to involve any danger from tipping.

(j-2)  Lay the planking running in the opposite direction at an angle so as to extend over and rest on the first layer of planking.

(k)  Maintain planks in good condition.  Do not use planks when cracks exceed 1.5 times the width of the board, when notches are deeper than 1/3 the width of the plank, or with saw kerfs marks.

(l)  When moving platforms to the next level, leave the existing platform undisturbed until the new bearers have been set to receive the platform planks.

(m)  Do not store materials on scaffolds or runways in excess of supplies needed for that shift.

(12) Access.

(a)  Provide an access ladder or equivalent safe access.

(b)  Where a built-in ladder is part of a scaffold system, it must the requirements for ladders according to chapter 24.

(d)  Install an adequate gate (that is, inward swinging or chain guard) at ladder access points.

Note.  For mast climbing scaffolding, swing scaffold, or other adjustable platform scaffolding systems, follow the fall protection requirements in chapter 21 or the manufacturer’s instructions, whichever is more stringent.

(e)  Hook-on or attachable ladders must be specifically designed for use with the type of scaffold.  Position them so as not to tip the scaffold.

(f)  When erecting or dismantling welded frame scaffolds, the end frames may be used as access provided the horizontal members are not more than 22 inches (55.9 cm) apart.

(g) The minimum clear length of the rungs must be at least 16 inches (40.6 cm). (h) The distance from the supporting surface to the first step of a ladder, stair, or frame designed to be climbed must not exceed 2 feet (0.6 m).

(13) Where the scaffold height exceeds four times the minimum scaffold base dimension (and including the width added by outriggers, if used), the scaffold must be secured to the wall or structure.

(a)  Place the first vertical and horizontal tie at this point.

(b)  Repeat vertical ties at intervals not greater than 26 feet (7.9 m) with the top tie placed no lower than four times the base dimension from the top of the scaffold.

(d)  When more stringent means of securing the scaffold are recommended by the manufacturer or an RPE, follow the more stringent requirements.

(14) When scaffolds are to be partially or fully enclosed, a QP must verify the adequacy of the number, placement, and strength of ties attaching the scaffold to the structure, taking into consideration wind loads and weather.

(15) When vehicles or mobile equipment are used or allowed adjacent to scaffolding, install substantial stop logs or barricades.

(a) The use of a ground guide is recommended, however, in such cases where it is determined that barricades are not feasible or they are not required based on distance, a ground guide will be used.

(b)  Do not expose ground guides to potential falling objects from the scaffold or the equipment.

(c)  Hanging scaffolds are exempt from this requirement unless the CP determines that vehicles or mobile equipment could pose a hazard to safe operation.

(16)  Do not use brackets on scaffolds unless the tipping effect is controlled.

(17) The following types of scaffolds must be designed and constructed according to ANSI A10.8:

(a)  Outrigger scaffolds.

(b)  Needle-beam scaffolds. (c)  Interior hung scaffolds.

(d)  Bricklayer’s square scaffolds.

(e)  Float/ship scaffolds.

(f)  Boatswain’s scaffolds.

(g)  Window jack scaffolds.

(h)  Carpenter’s bracket scaffolds.

(i)  Form scaffolds.

(18) Submit other types of scaffolding not included in ANSI A10.8 for review and approval by the USACE supervisor or acceptance by the KO or COR. The design must be approved by an RPE, or the system must meet a nationally recognized design standard.