Temporary Demountable Structures

First published 4th Feb, 2020

Events often involve the erection of temporary structures and these carry a risk and need to be managed by the Event Organiser appropriately.

All temporary structures must be properly designed, manufactured, erected and dismantled by competent and adequately resourced contractors/designers in accordance with the principles set out in the guidance document “Temporary Demountable Structures” 4th edition published by the Institution of Structural Engineers.

A signed safety (sign off) certificate must be provided for each temporary structure by the competent person responsible for the erection, stating that the structure/s have been built in accordance with the design and are safe and fit for purpose prior to the event.

All events should have wind management plan listing the maximum wind speed for each structure and the action to be taken at 60% and 80% of the maximum wind load capacity.  The plan must be monitored by a competent person against the operating limits of each of the temporary structures.  Effective action must be taken before any operating limits are exceeded.

HSE Guidance

HSE Guidance – examples

Small structures

Smaller structures including gazebos, covered stalls, umbrellas, signs etc. must be adequately secured or ballasted. The risk posed by these small structures should not be underestimated as they can be significantly affected by the wind (check forecasted average wind speeds and forecast gust speeds for the event day).  We expect an entry in your risk assessment to identify this risk and detail your mitigations.

Marquees

For large tents and marquees, it is recommended that the contractor is a member of MUTA or equivalent (For further information see the For large tents and marquees, it is recommended that the contractor is a member of MUTA or equivalent (For further information see the Best Practice Guide Safe Use and Operation of Temporary Demountable Fabric Structures.

Inflatable structures

See Inflatables

Fairground Rides and Amusements

See Fairground Rides and Amusements

Temporary Stands/Stages

Temporary Stands / Stages for use by 20 or more persons require an application to be made to Building Control under Section 27 of the County of South Glamorgan Act 1976 (details on the building control website).

Barriers / Fencing

Barriers must be fit for purpose and able to withstand the applied loading whether from wind or crowd loading.

Where pressure from an audience is expected e.g. in front of the stage at pop concerts, a properly constructed front of stage barrier will be required.

Documents

You should compile copies of the documentation for your structures and these should be submitted to ELP.  Detailed design calculations and drawings of each structure should be submitted in advance and they should also be made available for inspection on site.

A Construction Phase Plan may be required.

The following list covers the information that will be required by the structural engineer who forms part of the ELP. Detailed design drawings and calculations including any ballast / staking requirements and maximum allowable wind speeds shall be provided for the following temporary structures:

  • Marquees – if greater than 25m2
  • Stages – if greater than 25m2
  • All Screens
  • Barriers – Front of stage barriers, solid hording or mesh panels with scrim.
  • Gantries and Rigging – Any structure designed to support lighting, speakers or other flown equipment.
  • Scaffold structures e.g. race start/finish lines, signage and skate board ramps
  • Audience Seating Stands and Platforms – All
  • Staging/Lighting Towers – All
  • Any other structure – on request

For further specific information on barriers see The Event Safety Guide (HSG195) and the Institute of Structural Engineers publication Temporary Demountable Structures Guidance on procurement, design and use. (Third Edition) (2007).

Site Visit

A Cardiff Council Structural Engineer may attend site to undertake a visual survey of the temporary structures used in your event.  This is a chargeable service.  Up to £180 +VAT time charge is included in your hire fee.  We reserve the right to charge you for costs incurred over this amount due to failure to provide a complete set of documentation within the timescale agreed with the relevant ELP officer/venue.  The person who has specific overall responsibility for temporary structures should be available for this meeting.

Your specific requirements regarding structures will be confirmed once your event specific proposals are understood.

Note, there can be no changes to your proposed structures without prior approval and relevant paperwork being in place. The responsibility for safety and ensuring regulatory requirements are satisfied ultimately remains with the Event Organiser.

All event guidance