Scaffolding

Scaffold at Firestone Library

Scaffolding is widely used during construction and renovation activities.  In its simplest form, a scaffold is any temporary elevated or suspended work surface used to support workers and/or materials.  There are many types of scaffolds, both supported and suspended.  Included here are general requirements for all scaffolds.  Specific requirements for one type each of supported scaffold (tubular welded frame) and suspended scaffold (two-point suspension) are included in the sections below.

General Scaffolding Requirements

  • The footing of scaffolding must be sound and rigid, capable of supporting the weight. Scaffolding must not be placed on unstable objects, such as bricks or blocks.
  • Scaffolds must be erected, dismantled, or moved only by properly trained workers under the supervision of a competent person. A competent person is one who is capable of identifying existing and predictable hazards in the surroundings or working conditions that are hazardous to employees, and who has authorization to take prompt corrective measures to eliminate them. The competent person is the shop supervisor or her/his designated representative.
  • Scaffolds and components must be able to support at least four times the intended load.
  • Standard guardrails (e.g., handrail and midrail) and toeboards must be provided for all open sides of the scaffolding that are ten (10) feet or more above the surrounding surfaces.
  • Cross bracing is not acceptable as an entire guardrail system but is acceptable for a toprail when the crossing point of the two braces is between 38 inches (0.9 meters) and 48 inches (1.3 meters) above the work platform and for midrails when between 20 inches (0.5 meters) and 30 inches (0.8 meters) above the work platform. The end points of the cross bracing must be no more than 48 inches (1.3 meters) apart vertically.
  • To protect against falling objects, screens must be installed between the toeboard and midrail if anyone is required to pass under the scaffolding.
  • Any damaged or weakened component of a scaffold must be repaired or replaced immediately.
  • All planking or platforms must be overlapped a minimum of twelve (12) inches and secured from movement. Scaffold planks shall extend over their end support at least six (6) inches but no more than twelve (12) inches.
  • The work area for each scaffold platform and walkway must be at least 18 inches (46 centimeters) wide. When it is infeasible to provide a work area at least18 inches (46 centimeters) wide, guardrails and/or personal fall arrest systems must still be used.
  • A ladder or other safe means of access must be provided.
  • Access must be provided when the scaffold platforms are more than 2 feet (0.6 m) above or below a point of access. Direct access is acceptable when the scaffold is not more than 14 inches (36 centimeters) horizontally and not more than 24 inches (61 centimeters) vertically from the other surfaces. Cross braces shall not be used as a means of access.
  • Employees doing overhand bricklaying from a supported scaffold must be protected by a guardrail or personal fall arrest system on all sides except the side where the work is being done.

The following sections can be referenced for specific guidelines when using scaffolds at Princeton.

Scaffold Roles and Responsibilities

Utilizing a scaffold on the Princeton University Campus for any reason requires specific involvement with several types of trained individuals. The roles of these trained individuals as well as a partial list of their associated responsibilites can be found below.

Competent Person

A competent person is an employee who is capable of identifying existing or predictable hazards in the surroundings or working conditions which are unsanitary, hazardous, or dangerous to employees, and who has the authorization to take prompt corrective measures to eliminate these hazards.  Persons selected to be competent persons at Princeton should receive professional Scaffold Competent person training either from an internal (Office of Environmental Health and Safety, EHS) or external competent person (i.e. Scaffold Training Institute or similar vendor). Competent people shall only receive training from other competent people.  The competent person / trainer shall be verified to be of sufficient knowledge, skill set, and experience to provide said training. The department will designate, identify, and provide training for competent persons within the department. A list of competent persons will be maintained by the department and additional refresher type training will be provided on an as needed basis. The periodicity of this training to be determined by EHS and the department’s management, but should not exceed a period of 5 years from the previous training. The department also to provide competent person with document indicating that they are competent persons representing their respective departments and shall agree to uphold all local, state, and federal rules and regulations as they relate to scaffolding.

A competent person’s responsibilities include (but are not limited to):

  • Design and preplanning of the scaffold including weight limitations, scaffold type, fall protection, tie-offs, supports, etc.
  • Overseeing the erection of the scaffold
  • Final inspection of the scaffold prior to initial occupation for use.
  • At a minimum, daily inspection and documentation of the condition of the scaffold and its ability to be occupied safely.
  • Inspections of scaffolds after changes / alterations have been made.
  • Oversight and inspections of mobile scaffolds.
  • Training of other competent persons, scaffold erectors, and users.
  • Contact EHS for assistance and guidance in any of the duties associated with being a Competent Person.

Scaffold Erector

Scaffold erectors are those employees who have been designated (based on training and experience) by the department to be the employees who are responsible for the erection and maintenance of department scaffolds on the Princeton University campus. Only authorized scaffold erectors can erect scaffolds on campus. Erectors can solicit materials and components from other employees who may be on the ground, but the ultimate adding / subtracting of components to a scaffold shall be accomplished by an authorized scaffold erector. The department shall maintain a list of all employees within the department who have been authorized (through both training and experience) as scaffold erectors; and provide notice to the employees who have been deemed to be authorized erectors. Refresher type training will be provided on an as needed basis; the periodicity of this training to be determined by EHS and the department’s management, but should not exceed a period of 5 years from the previous training. Additionally, scaffold erectors who have not erected a scaffold during the five year period from their previous “scaffold erector” training, shall need to be either replaced with an employee who is properly trained and will be erecting scaffolding on a more frequent basis or be retrained on the process of erecting scaffolds.

A scaffold erector’s responsibilities include (but are not limited to):

  • Erecting scaffolds in accordance with local, state, and federal. Erectors also must abide by all manufacturer recommendations and be capable of erecting scaffolds under the guidance of a competent person.
  • Inspecting all scaffold components prior to assembly to insure that components used are of similar material and in good repair before becoming a part of the completed scaffold. This includes (but is not limited to): mudsills, screw jacks, frames, braces, planks, access ladders, brackets, etc.
  • Maintaining fall protection requirements while erecting / dismantling scaffolds.
  • Providing a scaffold to the user that is free from recognizable and preventable hazards (i.e. fall protection systems in place, falling object prevention in place, appropriate access / egress to and from the scaffold, appropriate anchorage and stability of the structure, appropriate walking / working surfaces, maintaining appropriate clearances from electrical hazards, etc.)
  • Prior to occupation scaffold erectors must notify the competent person that the scaffold has been erected and is ready to be inspected.
  • Training of other scaffold users if needed.
  • Contacting and coordinating with the Competent Person regarding any issues associated with the erection of a scaffold.
  • Contacting EHS if there is a concern regarding the erection of the scaffold.

Scaffold User

A scaffold user is defined as any employee who utilizes an elevated temporary work platform (scaffold) to perform work. Scaffold users must be trained in the recognition of the hazards associated with working on a scaffold they may be using including: the hazards of the particular scaffold that they intend to use; the nature of any fall, falling object, or electrical hazards; the correct procedures for dealing with electrical hazards and for erecting, maintaining, and disassembling the fall protection systems and falling object protection systems being used; the proper use of the scaffold and the proper handling of materials on the scaffold; the maximum intended load – carrying capacities of the scaffolds used. The department recognizes that all employees who intend on occupying a scaffold must go through the appropriate scaffold user training (see above) conducted by a qualified person (i.e. EHS staff Competent person, or qualified person). Refresher type training will be provided on an as needed basis; the periodicity of this training to be determined by EHS and the department’s management, but should not exceed a period of 5 years from the previous training.

A scaffold user’s responsibilities include (but are not limited to):

  • Examining the scaffold tag (which should be affixed near the access point) to verify that a competent person has deemed the scaffold safe for use. This must be done prior to initial use of the scaffold each shift.
  • Refusing to occupy a scaffold prior to the Competent Person providing documentation indicating that the scaffold has been inspected and deemed safe. Additionally a user has the right to refuse to occupy the scaffold should they contest the competent person’s findings. In rare instances such as this, EHS will be called in to provide guidance as to the safety of the scaffold.
  • Notifying the competent person of any safety concerns associated with the erection, conditions, use, and / or maintenance of the scaffold.
  • Utilizing scaffolds in accordance with all local, state, federal, manufacturer, and institutional rules and regulations.
  • Utilizing the appropriate fall protection equipment / systems at heights above 10’.

Scaffold Training

Scaffold planning, erection, and use require different levels of training.  Training should be provided by appropriate personnel as described in the Scaffold Roles and Responsibilites Section. Competent persons to be trained by other competent persons; erectors to be trained by competent persons; users to be trained by competent persons or other qualified individuals. Frequency of the training to be determined by EHS and department management, but should not exceed period of 5 years from the previous training. Refresher training also to be provided whenever there is an indication that the individual in question, whether they be a competent person, erector, user, or qualified person, exhibits a lack of understanding of the manufacturer, local, state, and federal requirements associated with the inspection, erection, or use of scaffolds. Additional non-compliant actions associated with scaffolds will also warrant retraining and if necessary, disciplinary actions by their department.

Scaffolding Erector Training    Scaffold Competent Person Training

Specific Requirements of Welded Frame and Suspended Scaffolds

Supported Scaffold (Tubular Welded Frame)

  • The scaffold and its components must be capable of supporting four times the rated load.
  • Cross-braces of the proper length must be used to ensure that the scaffold will remain plumb and rigid.
  • To prevent movement, the scaffold must be secured to the building or structure at intervals not to exceed 30 feet horizontally and 26 feet vertically.
  • Outriggers must be used on narrow frame type scaffolds (i.e. Baker, Perry, Bil-Jax) whenever frames are stacked more than one section high.
  • Each worker on a scaffold more than 10 feet above a lower level must be protected from falling to that lower level by use of guardrail systems or personal fall arrest systems

Mobile Scaffolds

  • Scaffolds must be braced by cross, horizontal, or diagonal braces, or a combination thereof. Scaffolds must be plumb, level, and squared. All brace connections must be secured.
  • Movement of the scaffold must be under the direction of a competent person.
  • Scaffold should not be occupied while moving unless a competent person has determined it is safe to do so.
  • Rolling scaffold must not be used on sloped surfaces.
  • Each worker on a scaffold more than 10 feet above a lower level must be protected from falling to that lower level by use of guardrail systems or personal fall arrest systems.

Swinging Stage Scaffolds (Two-Point Suspension)

  • The platform of a two-point suspension scaffold must not be more than 36 inches wide unless designed by a qualified person, and must be surrounded with a standard guardrail and toe board.
  • Ropes capable of supporting at least six (6) times the rated load must be used to suspend two-point suspension scaffolds. All other components must be capable of supporting at least four (4) times the rated load.
  • The use of repaired wire rope is prohibited.
  • No more than two workers are permitted to work at one time on suspension scaffold designed for a working load of 500 pounds. No more than three workers are permitted to work at one time on suspension scaffolds with a working load of 750 pounds.
  • Each worker on a suspended scaffold must be protected by a personal fall arresting system attached to an independent lifeline. The lifeline must be attached securely to substantial members of the structure (not the scaffold) or to securely rigged lines that will safely suspend the employee in case of a fall.
  • Tiebacks must be secured to a structurally sound anchorage on the building or structure.
  • Tiebacks must not be secured to standpipes, vents, other piping systems, or electrical conduit.
  • A single tieback must be installed perpendicular to the face of the building or structure. Two tiebacks installed at opposing angles are required when a perpendicular tieback cannot be installed.
  • Independent lifelines should be protected from abrasion and wear.
  • Only those items specifically designed as counterweights must be used. Sand, gravel, masonry units, rolls of roofing felt, and other such materials shall not be used as counterweights.
  • Counterweights used for suspended scaffolds shall be made of materials that cannot be easily dislocated.
  • Counterweights shall be secured by mechanical means to the outrigger beams.

Boatswain's Chair and Ladder Jack

  • Each worker 10 feet (3.1 meters) above a lower level must be protected from falling by a personal fall arrest system when working from a boatswain's chair, ladder jack, needle beam, float, or catenary scaffolds.

Aerial Work Platforms

Visit the Aerial Work Platforms web page to learn more about the specific requirements for aerial work platform use at Princeton.