Scaffold Safety Quick Links
Scaffold Safety Program Summary
Information regarding the proper erection, inspection, and use of supported scaffolds.
Departments must ensure that a competent person is designated to provide oversight for all activities involving scaffolding, and that personnel using the scaffolding have been properly trained and are following established safety requirements. This competent person directly supervises employees erecting, moving, dismantling, or altering a scaffold, and conducts inspections. Scaffold Competent Person level training through Environmental Health & Safety is required.
Personnel accessing the scaffolding to perform tasks (i.e. users) must attend Scaffold Awareness training, and are responsible for following guidelines regarding the safe use of the scaffolding.
Each department that owns and uses scaffolding must designate a competent person to provide oversight of erection, alteration, dismantlement, and use of supported scaffolding. This program applies to all departments that use, erect, move, after, or dismantle supported scaffolding for work-related purposes regardless of location.
This program applies to all departments that use, erect, move, alter, or dismantle supported scaffolding for work-related purposes regardless of location or ownership of scaffolding (i.e. rented and/or installed by a vendor/contractor).
Scaffold Safety Online Program
Scaffolding violations consistently remain in OSHA's top 10 list for most-cited standards. The sections of the standard most cited include:
- Failure to provide fall protection;
- Failure to provide proper access;
- Failure to ensure adequate platform construction;
- Failure to properly support scaffolding; and
- Lack of personal fall arrest or guardrail systems.
The purpose of this program is to provide guidance for proper setup, use, and oversight of work activities involving scaffolding. Guidelines are based upon OSHA regulations and industry best practices.
Each department that owns or uses scaffolding must designate a competent person to provide oversight for related activities, such as erecting, moving, altering, dismantling, and inspection. Departments must also ensure that any person using or accessing scaffolding is properly trained in safe use and recognition of related hazards.
This program currently only applies to supported scaffolding, including mobile scaffolds, being erected, moved, altered, dismantled, or used by Virginia Tech personnel regardless of location or ownership.
If suspended scaffolds will be used by Virginia Tech personnel, please contact Environmental Health & Safety for guidance.
Environmental Health & Safety is responsible for developing, implementing, and administering the Scaffold Safety Program. This involves:
- Training all users in the associated hazards and general safe work practices.
- Maintaining centralized records of training and certification records.
- Providing technical assistance to university personnel.
- Evaluating the overall effectiveness of the program on a periodic basis.
Departments are expected to maintain a safe and healthy living, learning, and working environment for faculty, staff, students, and visitors to our campus. Departments must ensure equipment provided is of a safe design and in good condition and should designate responsible persons to coordinate the requirements of this program with employees. Designated persons must attend Environmental Health & Safety Scaffold Competent Person training.
Employees are expected to attend Environmental Health & Safety Scaffold Awareness Training and to use the equipment in a safe and responsible manner. Where employees will be accessing scaffolding this has not been erected and inspected by the department (i.e. it belongs to another department or was erected by a contractor), the designated departmental scaffold competent person must inspect it and approve its use prior to employees accessing the scaffold.
Contractors must comply with all local, state, and federal safety requirements, and assure that all of their employees performing work on Virginia Tech properties have been suitably trained. Contractors must also comply with the requirements outlined in Virginia Tech's Contractor Safety Program.
Scaffold Competent Person Training
Each employee who will provide oversight to scaffolding activities must attend Scaffold Competent Person training offered by Environmental Health & Safety prior to being assigned such responsibilities.
Additionally, each Scaffold Competent Person must attend Fall Protection User training, which includes the use of personal fall arrest systems.
Scaffold Awareness Training
Personnel accessing scaffolding to perform work tasks must attend awareness level training in safe work practices, and to ensure that related hazards are recognized and corrected prior to scaffold use.
Scaffolds that will be greater than 125 feet in height above their base plates must be designed by a registered professional engineer (i.e. a qualified person)
Lean-to scaffolds are prohibited. Lean-to scaffolds are supported by tilting it toward and resting upon a building or structure.
Shore scaffolds are prohibited. Shore scaffolds are placed against a building or structure and are held in place with props.
When preparing for work involving scaffolding, it is important to consider the following:
- What will be the intended use of the scaffolding? Consider what work tasks will be performed, anticipated loads for people, materials, and equipment, any unique building configurations which may create a problem, and electrical or piping obstructions which are in the area.
- What are the site conditions? Will the scaffolding be set up on a concrete foundation, pavement/asphalt, or earth? If set up on earth, what class of soil is present, and is the area level? Are there weather conditions to consider?
- How high will the scaffolding be and will it need to be secured to the building structure or designed by a qualified person?
- Will pedestrians be affected? Building accesses must be maintained and overhead protection may be required.
Each scaffold and scaffold component shall be capable of supporting, without failure, its own weight and at least four times the maximum intended load applied or transmitted to the scaffold. To figure the maximum intended load, total the weight of all persons, equipment, tools, materials, transmitted loads, and other loads reasonably anticipated to be applied to the scaffold (or scaffold component) at any one time. Persons are estimated at 250 pounds each.
Rated load capacity
Scaffold and scaffold components shall not be loaded in excess of their maximum intended load or rated capacity, whichever is less. The rated load capacity of a scaffold is defined below.
Rated Load Capacity of Scaffold
Intended Load Should Be
25 pounds per square foot
50 pounds per square foot
75 pounds per square foot
The maximum weight that can be applied to the scaffold is determined by data supplied by the manufacturer, expressed as permissible load per square feet (e.g. 25 psf, 50 psf, or 75 psf) multiplied by the square footage of the scaffold work surface.
A simple method to determine if a scaffold is overloaded is the Deflection Method. Platforms, planks, or decking must not deflect more than 1/60 of the span when loaded. The deflection is measured with a tape measure and a straight edge.
Employees shall be prohibited from working on scaffolds covered with snow, ice, or other slippery material (ex. mud), except as necessary to remove such materials. Work on or from scaffolds is also prohibited during storms or high winds unless a competent person has determined that it is safe for employees to be on the scaffold and those employees are protected by personal fall arrest systems or windscreens.
- Windscreens shall not be used unless the scaffold is secured against the anticipated wind forces.
- Where uplift can occur which could displace scaffold end frames or panels, they shall be locked together vertically with pins or equivalent.
Debris shall not be allowed to accumulate on work platforms. Scrap material, mortar, demolition materials, etc. shall be removed regularly in a safe and orderly manner.
Ladders or makeshift devices, such as boxes, barrels, chairs, cans, etc. shall not be used on top of scaffold platforms to increase the working level height of employees.
When working or erecting scaffolding in the vicinity of overhead electrical lines, it is critical that minimum clearances are observed and/or that power lines are de-energized or insulated by the power company. Clearances apply to the tools and equipment being used in the vicinity of the power lines, materials being handled, any scaffolding component, and any part of a person's body. For clearance distances for insulated and uninsulated power lines, click here.
The scaffold competent person must inspect the scaffold before each shift and after any occurrence which could affect the integrity of the scaffold, such as being bumped by a vehicle, damaged, or excessive rain, or freezing/thawing of the ground which could affect the foundation. Scaffolding should be inspected for visual defects, such as:
- Bent or damaged components
- Missing guardrails or crossbracing
- Proper access
- Unstable foundation
The scaffold competent person must be notified immediately if a component becomes damaged after erection, and the scaffold must not be used until the damaged component has been properly repaired or replaced.
Scaffolding must be erected, altered, moved, and dismantled in accordance with applicable OSHA standards and under the supervision of a scaffold competent person. Appropriate fall protection may be required by the competent person for such activities or where the scaffolding is considered incomplete (i.e. missing parts due to area obstructions).
Scaffold components cannot be mixed if they are from different manufacturers unless they fit together without force. Scaffold components of dissimilar metals should not be used together unless the competent person has determined that galvanic action will not reduce the strength of any component.
Supported scaffold poles, legs, posts, frames, and uprights shall bear on base plates and mud sills (or other adequate firm foundation). The size of the mudsill shall be based on the type of soil the scaffold will be erected upon.
|Scaffold Height||Minimum Mud Sill Size|
|Scaffolds 4 levels or less in height||2" x 10" pad, 12" - 18" long|
|Scaffolds > 4 levels on Type A Soil||2" x 10" pad, 18" long|
|Scaffolds > 4 levels on Type B Soil||2" x 18" x 18" pad|
|Scaffolds > 4 levels on Type C Soil||2" x 36" x 36" pad|
The base and mudsill must provide a solid surface for the feet to sit upon so that the scaffold doesn't sink, move, settle, or shift. Unstable objects, such as bricks, cinder blocks, buckets, scrap lumber, etc., shall not be used to support or level scaffolds. Screw jacks must be used to level scaffolding on uneven surfaces. The maximum extension for a screw jack is 18 inches high. Most screw jacks will have a built-in stop so that the maximum height cannot be exceeded. (For mobile scaffolds, the maximum height of the screw jack is 12 inches.)
Supported scaffold poles, legs, posts, frames, and uprights shall be plumb (i.e. perfectly vertical) and braced to prevent swaying and displacement. Crossbracing is required on both the front and back sides of each scaffold buck or frame. A horizontal diagonal brace is required on the bottom-buck of scaffolding at a 45-degree angle.
To check a scaffold for being plumb, use a level on two opposite uprights. To make sure the scaffold is level, use a level on a horizontal support or bearer. To ensure the scaffold is "square," use a tape measure and measure the distance between opposite corners. The two measurements should be equal
Scaffold frames (i.e. bucks) must be joined together vertically by coupling or stacking pins (or equivalent means).
Scaffolds with a height-to-base width ratio of more than four to one shall be restrained from tipping over by guying, tying, bracing, or equivalent means. Guys, ties, and braces shall be installed where horizontal members support both inner and outer legs. Guy wires and ties prevent the scaffolding from tipping away from the building or structure, and braces are rigid support that prevents the scaffold from tipping into the building/structure.
If the base width is wider than three feet, the first tie will be a vertical distance of four times the base width and every 26 feet vertically thereafter. For example, if the base width is 5 feet, the first vertical tie will be (5 feet x 4) 20 feet from the ground.
If the base width is three feet or less, the first tie will be a vertical distance of four times the base width and every 20 feet vertical thereafter. For example, if the base width is three feet, the first vertical tie will be (3 feet x 4) 12 feet from the ground.
For long (running) scaffolds, guys, ties, and braces shall be installed at each end of the scaffold and at horizontal intervals not to exceed 30 feet.
Platform/decking planks may be made of solid sawn wood, manufactured wood, manufactured steel, or manufactured aluminum. If solid sawn wood is used, it must be scaffold grade.
- Note: Once a plank has been used as a mudsill, it cannot be used as decking again.
Scaffolds must be fully planked or decked whenever possible. The space between the last plank and the uprights cannot exceed 9 1/2 inches. The space between planks cannot exceed 1 inch, except where necessary for obstructions. Platforms and walkways, in general, must be at least 18 inches wide.
Where the platform will not be more than 14 inches from the face of the work (18 inches for plastering and lathing operations), fall protection is not required. The face of the work (example: the side of a building) basically serves as the fall protection system.
The ends of each platform must be cleated or restrained by hooks (or equivalent) to prevent accidental displacement or must extend at least 6 inches over the centerline of the support.
- The maximum extension of the plank cannot be more than 12 inches for planks that are 10 feet long or less.
- For planks that are greater than 10 feet long, the maximum extension past the centerline of the support is 18 inches.
- Where platforms overlap to create a running scaffold, the overlap must occur only over a support and shall not be less than 12 inches unless nailed together.
Where a platform changes direction (ex. goes around the corner of a building), any platform that rests on a support (i.e. bearer) at an angle other than a right angle, shall be laid first. Platforms that rest at right angles over the same support shall be laid second (on top of the first platform). The objective is to reduce the tripping hazard by having the ends of the top layer of planks form a straight line, rather than a saw-toothed edge, which increases tripping hazards.
Wooden platforms (i.e. decking, planks) must not be painted to hide defects. They may, however, be treated periodically with clear preservatives, fire-retardants, and/or slip-resistant finishes.
Proper access must be provided to access the work platform of the scaffold.
- Ladders that are a part of the scaffolding system, such as hook-on and attachable ladders, shall be positioned so that the bottom rung is not more than 24 inches above the supporting level.
- Portable extension ladders used to access the work platform must meet OSHA design and use criteria, which includes securing the ladder to the scaffold at the top and bottom and having the ladder extend at least three feet past the landing surface. Ladders must also be positioned so as not to tip the scaffold.
- Stair towers must have hand and midrails on each side of the stairway. Stairs must be at least 18 inches wide and have a landing platform at least 18 inches long at each level. Stair treads must be of slip-resistant design. The riser height must be uniform, and the stair angle must be between 40 and 60 degrees from the horizontal.
- Where the frame of the scaffold will be used for access, the manufacturer must specify in writing that it was designed for such purposes. Design features include a rest platform every 35 feet, rungs at least 11 1/2 inches wide (8 inches for ladders built into the frame), and uniform rung spacing not exceeding 16 3/4 inches.
At Virginia Tech, a fall protection system (i.e. guardrail system) must be installed on all scaffolds with a working height greater than 4 feet. The guardrail system shall be installed along all open sides and ends of the platform before being used as a work platform by employees. One exception is when the scaffold platform is within 14 inches of the face of the work.
Top rails (manufactured after 1/1/2000) must be 38 - 45 inches above the platform surface. (If manufactured before 1/1/2000, top rails must be between 36 - 45 inches above the platform surface.) Top rails must be capable of supporting at least 200 pounds applied in a downward or outward direction.
- Note: Crossbracing is acceptable in place of a top rail when the crossing point of the two braces is between 38 - 48 inches above the work platform. It cannot serve as both a mid-rail and a top rail.
Midrails must be installed at a height approximately midway between the top rail and the platform surface. Midrails must be capable of supporting at least 150 pounds applied in a downward or outward direction.
- Note: Crossbracing is acceptable in place of a mid-rail when the crossing point of the two braces is between 20 - 30 inches above the work platform. It cannot serve as both a mid-rail and a top rail (as incorrectly done in this picture).
Toeboards must be installed on work platforms where materials or tools will be in use. Toeboards must be installed not more than 1/4 inch above the platform and securely fastened. They may be made of solid material or mesh with openings no greater than 1 inch. Toeboards must be capable of withstanding at least 50 pounds applied in a downward or outward direction.
Nets and platforms
Additional protection from falling debris and other small objects must be provided in areas where personnel will be in the vicinity of scaffolds. Such protection may be in the form of:
- Barricades to keep personnel out of a hazardous area;
- Screens which are erected between the toe board and handrail of the work platform;
- Debris nets to catch materials before they hit the ground; or
- Canopy structures are made of solid materials.
Large or heavy materials stored on the scaffold platform must be located away from the edges of the work platform and secured, if necessary.
Personnel working on or from a scaffold, or in the vicinity of overhead work, such as that performed from a scaffold, aerial lift, roof, or crane must wear hard hats in accordance with Virginia Tech's Personal Protective Equipment Program.
In addition to requirements for the proper erection of supported scaffolds (with the exception of the requirement for a base plate and mudsill), mobile scaffold casters and wheels shall be locked with positive wheel and/or wheel and swivel locks to prevent movement of the scaffold while the scaffold is in use.
Casters shall be pinned or otherwise secured to the scaffold legs or screw jacks.
The manual force used to move a mobile scaffold shall be applied as close to the base of the scaffold as practical, but not more than 5 feet above the supporting surface. Employees shall not be allowed to ride on scaffolds being moved unless the following conditions exist:
- The surface on which the scaffold is being moved is within three degrees of level and free of pits, holes, and obstructions.
- The height-to-base width ratio of the scaffold during movement is two to one or less.
- Outrigger frames, when used, are installed on both sides of the scaffold.
- The force of powered systems, when used, is applied directly to the wheels and does not produce a speed of more than one foot per second.
- Employees are within the guardrail system.
Horizontal diagonal bracing is required on mobile scaffolds near the bottom and every 20 feet vertically for support and stability.
Screw jacks shall be used to level the scaffold, if necessary. The maximum extension is 12 inches.
The competent person will determine if personal fall protection systems are required for disassembly. Scaffolding must be disassembled in a safe and orderly fashion.
- Scaffolds should be disassembled from the top down; therefore, it is important that the scaffold is in good condition and as complete as possible before beginning.
- Check scaffolding to see if it has been structurally altered in any way. Not only is it unsafe to work from such a scaffold, but it is equally dangerous to attempt to disassemble one.
- Reconstruct the scaffolding if components have been removed during the course of work.
- Use proper access (i.e. ladder).
- Components must be lowered down by handing from one person to another or lowered by attaching to a rope. Never throw or drop components to the ground, which may result in damage or structural defects.
- Components should be stockpiled in an orderly manner in an area protected from the elements.
Bearer: A horizontal transverse scaffold member upon which the scaffold platform rests and which joins scaffold uprights, posts, poles, and similar members. Also referred to as a "putlog."
Brace: A rigid connection that holds one scaffold member in a fixed position with respect to another member, or to a building or structure.
Cleat: A structural block used at the end of a platform to prevent the platform from slipping off its supports. Cleats are also used to provide footing on sloped surfaces such as crawling boards.
Competent Person: One who has been trained to identify hazards related to scaffolding, or working conditions that are unsafe, unsanitary, hazardous, or dangerous for employees, and who has the authority to have these hazards eliminated or controlled. The competent person provides oversight and inspection of the scaffolding, and supervises the erection, moving, dismantling, or alteration of a scaffold.
Mobile scaffold: A powered or unpowered, portable, caster or wheel-mounted supported scaffold.
Outrigger: The structural member of a supported scaffold used to increase the base width of a scaffold in order to provide support for, and increased stability of, the scaffold.
Personal fall arrest system: A system used to arrest an employee's fall. It consists of an anchorage point, connectors (i.e. lanyard or connecting device), and a body harness.
Platform: A work surface elevated above lower levels.
Qualified person: One who by possession of a recognized degree, certificate, or professional standing, or who by extensive knowledge, trainig, and experience, has successfully demonstrated his/her ability to solve or resolve problems related to the subject matter, the work, or the project. With regards to scaffolding, a qualified person may design scaffolding and determine appropriate anchor points for fall protection systems to be used.
Rated load: The manufacturer's specified maximum load to be applied to a scaffold or scaffold component.
Supported scaffold: One or more platforms supported by outrigger beams, brackets, poles, legs, uprights, posts, frames, or similar rigid support.
Suspended scaffold: One or more platforms suspended by ropes or other non-rigid means from an overhead structure(s).
Walkway: A portion of the scaffold platform used only for access and not as a work level.
Frequently Asked Questions
No, however tagging the scaffold as "complete" (green tag), "incomplete" (yellow caution tag), or "do not access" (red danger tag) is a best practice highly recommended, especially where various groups will be accessing the scaffold. It serves as a means of communication between the scaffold competent person and those using a scaffold.
Yes, but once it has been used as a mud sill, it cannot be used as a platform plank again.
No, but the scaffold competent person must be onsite to perform daily inspections of the scaffolding and available if problems or questions arise.
Not necessarily. You may assume the worst class of soil (Class C) and use mud sills of the required size for that class of soil.
Is training mandatory? If so, when? Yes. All persons who work on or around scaffolds must attend this training.
Class length: 1 hour.
Available online: Yes.
When is refresher training required? Every 5 years.
Please see the online class schedule for more information.
Is training mandatory? If so, when? Yes. All departments that use scaffolding must designate one or more persons in the department to oversee these operations.
Class length: 3 hours.
Available online: Yes.
When is refresher training required? Every 3 years.
Please see the online class schedule for more information.
Robin McCall-Miller, Occupational Safety Program Manager