![]() ![]() The collapse of the scaffold due to improper erection.Falls from scaffolding due to improper guardrail installation.Various incidents confirm the high frequency of scaffolding hazards. Studies represent that more than 65% of the construction workforce needs to work on scaffolds. Scaffolding hazard increases with an increase in height. When wooden boards are used as scaffolding floor material, their ends are protected by metal plates known as hoop irons or nail plates. Scaffolding floors are normally made of wooden boards or decking made from steel or aluminum. The widely used materials for scaffolding are Steel and Aluminum. Guardrails along all open sides and ends shall be installed before releasing the scaffold for use by employees, other than the erection and dismantling crews.Loads in excess of their maximum intended loads or rated capacities shall not be applied on scaffolds and scaffold components.Each scaffold and scaffold component should be designed to support its own weight and at least four times the maximum intended load applied or transmitted to it.Scaffolding where heavy loads are expected must be checked for this deflection criteria.Īs per OSHA Scaffolding guidelines, the following considerations should be taken into account for scaffolding design: To avoid cracking the floor the beam deflection must be limited to 1/360 of the span. Dead (Weight of Structural members), Live loads (Weight of Persons), and Occasional loads (wind, earthquake, snow, etc) are to be considered. Scaffolding design should consider the worst load combination expected during its service period. The following codes and standards are used for the design of scaffolding: OSHA scaffolding standard (1926.451), NZS 3404.1, NZS 3603, AS 1538, AS 1664, AS 1554.1, AS 1665 or NZS 4701, as appropriate. Nature of surrounding supporting structure etc.Time Period for the scaffolding to be erected.The following information is required for designing the scaffold. The safety of personnel associated with the erection, alteration, and dismantling of the scaffold the safety of persons using the scaffold and the safety of persons in the vicinity of the scaffold.The supporting structure should be sufficient in strength, stability, and rigidity.The design of the scaffold should consider the following: Scaffolding DesignĪs Scaffolding involves the safety of working professionals it must be designed with utmost care. Suspended Scaffolding which is suspended by non-rigid members from overhead structures.Suitable bracing should be provided to prevent swaying and excessive displacement of these structural members. Supported Scaffolding supported by rigid load-bearing members: Supported scaffolds are elevated platforms supported by legs, uprights, posts, frames, outrigger beams, brackets, poles, or similar rigid support.Putlogs: Putlogs are transverse members that are placed on one end on ledgers and the other ends at right angles on the wall.Īs per Occupational Health and Safety Administration(OSHA) Scaffolding is classified into two groups.Boards: Steel, Aluminium, or wooden boards that provide the working area.Diagonal Braces: Strengthen the basic structure to carry more loads.They are of three types Putlog Coupler, Swivel Couplers, and Right Angle Couplers. Couplers: Fittings to hold tubes together.Scaffolding Tubes: Steel or Aluminium tubes are used in scaffolding.Transom or Bearer: Transoms are used to support standards and they are at the right angles to the ledgers.Ledgers decide the height of the working platform. ![]()
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