Preventing structural collapse during demolition

The purpose of this news article is to remind employers and those in control of demolition sites to verify the load capacity of suspended concrete slabs before they place machinery or rubble on them.

Risk controls

Before commencing demolition, ensure the following:

  • A sequential and comprehensive demolition plan is to be prepared that is specific to the site and is approved by a competent structural engineer. Specifically, the plan should consider the rate of demolition and outline the load capacity limits of floors, ramps or other suspended slabs. If temporary supports are required, their specification and positioning should clearly be shown in the plan.
  • Consideration must be given to the method for moving plant from floor to floor. If using ramps, the loads on the structure should be verified. In particular, the ramp’s specifications, location and the placement of temporary supports should be documented in the demolition procedure.
  • Consideration must also be given to the means for clearing rubble from floors or other suspended slabs to prevent a build-up of rubble in excess of that specified in the demolition plan.
  • Exclusion zones are to be established to keep unauthorised people outside of potential collapse zones.

During demolition, the person in control of the work must ensure the following:

  • Work is to be supervised by a competent person(s) and done safely.
  • The documented demolition procedure is to be followed. If changes to the procedure are proposed, they are not to be implemented until they are verified, in writing, by the structural engineer.

Such changes can concern the following:

  • The installation of temporary supports according to manufacturer’s instructions and their positioning according to specifications in the demolition procedure.
  • Instructions on when to remove rubble to prevent slabs being overloaded.
  • Instructions on where a ramp is to be used and whether it needs temporary supports.
  • The prescribed distances between machines when they’re located on slabs.

Assetmark Group reminds employers and those in control of demolition sites to ensure they verify the load capacity of suspended concrete slabs, before loading them with demolition machinery and/or rubble. Additional temporary support eg propping – may be needed to enable the floors to hold the demolition loads.

Should you need further advice and information on your project, please contact your nearest Assetmark Group office.

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