What to Check Prior Erection of Scaffolding (both mobile and fixed)
All scaffolding, regardless of height or whether a certificate of competence is required.
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· Knowledge of the basic rules of physics and mathematics as they apply to scaffolding.
· Ability to read and understand suppliers’ information, general site plans, design drawings and specifications for scaffolds.
· Thorough knowledge of the scaffolding equipment being used.
· Thorough knowledge of the assembly methods and design requirements associated with scaffolding equipment.
· Ability to identify the common hazards of scaffolding work and take effective precautions to control the risks resulting from the hazards.
· Competency to visually inspect scaffolding equipment for faults.
· The physical skills needed for scaffolding construction.
· Competency in manual lifting techniques.
· Ability to work safely and confidently at heights.
· Ability to use scaffolding tools and equipment correctly.
· Ability to erect and dismantle scaffolding in the correct sequence.
· Knowledge of the prevention of falling objects.
To undertake a site assessment, consider the following:
· What is the purpose of the scaffold, and who will be using it?
· What is the nature of the ground, surface or structure on which the scaffold is to be erected? Does it need to be verified for load-bearing capacity?
· How will the scaffold be stabilised from overturning? If it will be tied to a structure, how will this be done?
· Will the scaffold be subject to environmental loads such as funnelling wind, vehicle impact, or snow?
· How will workers and vehicles access the site and the area for storage of material and equipment?
· Does the scaffolding create risk for workers on or around it?
· Are there electrical conductors or cables in the vicinity of the scaffold? Could the scaffold or workers come into contact with them at any stage of the scaffolding process? That could include delivering scaffolding equipment to the site, erection, associated scaffolding use and work activity, and eventual dismantling/removal from site.
· Is there sufficient space to erect the scaffold and store scaffold materials?
· Is the scaffold to be erected on a public roadway or footpath, and what are the local authority requirements?
· How will the site be protected from unauthorised access?
· Is pedestrian access through the site required? How will this be managed?
· Is a specific traffic management plan required?
· Are there any other potential hazards specific to the site?
When organising site security and site access, consider:
· warning or hazard signs
· supervising authorised visitors
· the risk of unauthorised access occurring (consider schools, parks, shops or other public places, or amenities and events nearby)
· pedestrians and other members of public
· other workers and mobile plant on site
· vehicle traffic control within and near the site
· delivery points, including vehicle access and egress
· immobilising/locking vehicles
· safe and secure storage of materials (eg stacked equipment)
· control of energy sources (eg temporary mains service boxes)
· suitably designed and constructed physical barriers (eg safety fences, lockable gates, or covers).
If the scaffolding is partly or completely within a confined space, make sure:
· workers are trained in confined space entry and enough workers are available to carry out a rescue in the event of an emergency
· an entry permit system is established
· a permit is completed and approved by the supervisor or forman in charge of the confined space
· pre-entry tasks are established and understood by all
· the atmosphere is tested before entry and continuously monitored during entry, if necessary
· ventilation is installed and adequate where deemed necessary
· an emergency plan is established and tested
· suitable standby person/s are present, trained and aware of their specific tasks in the event of an emergency
· communication is established with the standby person/s
· all equipment is suitable and operational, within current inspection dates, and used by workers trained in the use of the equipment.
The job site should be inspected for ground conditions, strength of the supporting building, proximity to power lines (minimum distance of 10 feet must be maintained between energized power lines and the scaffolding) and overhead obstructions. Wind conditions and weather protection covering are also important considerations. Frame spacing and mudsill size can only be determined after calculating the total loads to be imposed on the scaffolding and the strength of the structure. The load carrying capacity information for scaffolding components is available from the manufacturer.
Stationary or fixed scaffolding over 125 feet in height and movable or rolling scaffolding over 60 feet in height must be designed by a professional engineer. Before erecting scaffolding all equipment must be inspected to make sure that they are in good condition and are serviceable. Damaged or deteriorated equipment should not be used. Wood planks used for scaffolding must be specifically approved and marked by an approved grading agency.
Erection Fixed Scaffolding
Everyone who is erecting moving or dismantling or using scaffolding must wear hardhats. Special care must be taken when erecting scaffolding on soft, frozen or filled ground. Sills must be level and in full contact with the supporting surface. Base plates and screw jacks with base plates must be in firm contact with both sills and the legs of the scaffolding. Only screw jack must be used to compensate for uneven ground. Unstable objects like wooden blocks, bricks or stones must not be used.
Erection of Rolling or Mobile Scaffolding
The height of the tower must not exceed four times the base width. Out riggers may be used on both sides of the tower to increase the base width when necessary. All casters must be secured to the frame or screw jacks with nuts and bolts or other secure means. The weight including the load of the tower must not exceed the capacity of the casters. Casters must be locked unless the scaffold is being moved. All frames of the tower must be cross-braced.
1. OSHA requires that scaffolding to be secured to the building when the height of the scaffolding exceeds four times the minimum base width.
2. The bottom tie to the building must be placed no higher than four times the minimum base width and every 26 feet vertically thereafter. The ties must be placed as close to the top as possible in case they are less than four times the minimum base width of the scaffolding.
3. Vertical ties must be placed at the end of the scaffolding and at no more than 30 feet horizontal intervals.
4. The ties must be installed as the erection progresses and not removed until the scaffolding is dismantled to that height.
5. Side brackets, cantilevered platforms, pulleys or hoists and wind conditions must be considered and compensated with additional ties/or guides.
6. Circular scaffolding erected completely around or within the structure must be restrained from tipping by using “stand-off” bracing members.
7. Guardrails are required on welded frame scaffolds that are 10 feet high or more. Top rail height must be 36 inches to a maximum of 45 inches. Top rails must be able to withstand at least 200 pound of out ward pressure and mid rails at least 150 pounds.
8. Cross bracing is acceptable in place of guardrails, if the cross bracing is between 20 and 30 inches above the platform. Cross bracing between 38 and 48 inches above the platform may serve as the top rail.
9. For scaffolding over 10 feet, each employee must be protected by the use of personal fall protection systems when guard rail are not provided.
10. In addition to wearing hard hats, each employee on a scaffold shall be protected from falling hand tools, debris and other objects by erecting toe-boards or screens.
11. Spaces between scaffold planks must be no more than one inch. An uncleated scaffold plank must extend over the end support a minimum of 6 inches.
12. Scaffold platforms above one section high must be provided with safe access by providing ladders or stair cases. When hood-on ladders are used, there must be a rest platform every 35 feet.
13. The scaffold distance from a 220-volt line must be at least 3 feet.
14. Workers must not be permitted in winds above 30 MPH.
15. Pre shift inspections must include checking the following:
A) Base plates and mudsills for proper placement and stability.
B) Cross bracing to make sure the structure is square.
C) Guardrails for secure construction and proper placement.
D) Platforms for splits, cracks and worn or damaged areas.