Temporary demountable structures (TDS) are a common and essential feature of modern events, from music festivals and sporting fixtures to corporate gatherings and markets. These structures, which include stages, marquees, seating stands, lighting towers, and screens, are designed to be erected and dismantled repeatedly. However, their temporary nature means they pose specific safety challenges that must be addressed with meticulous planning and strict adherence to safety protocols.
The primary responsibility for the structural adequacy and safety of these structures lies with the event organiser. While Building Control legislation does not typically cover these structures, local authorities and event safety advisory groups (SAGs) require organisers to demonstrate they have taken all reasonable steps to ensure public safety.
Key Safety Considerations and Best Practices
To ensure a temporary structure is safe and fit for purpose, event organisers should follow a structured approach covering the entire lifecycle of the structure — from procurement to dismantling.
1. Procurement and Design
The foundation of a safe structure is a competent design. Event organisers should ensure their contractors are qualified and have a proven track record.
- Competence is Key: The design, manufacture, and installation of all temporary structures must be carried out by competent contractors with the necessary qualifications and resources.
- Documentation: Event organisers should request and review detailed documentation at least 28 days before the event. This includes design drawings, structural calculations, and a statement of the maximum wind speed the structure can withstand. The Institution of Structural Engineers (IStructE) and the Health and Safety Executive (HSE) provide extensive guidance on this.
- Smaller Structures: Don’t underestimate the risk of smaller structures like gazebos, market stalls, and signage. They must be adequately secured with ballast weights or anchors, and a risk assessment should be completed to manage their vulnerability to wind.
2. Erection and On-Site Management
Once on-site, the installation process and ongoing management are crucial.
- Independent Erection Check: Before an event opens to the public, an independent, competent person must inspect the erected structure to verify it has been built correctly and in accordance with the design. The event organiser should obtain a signed “completion certificate” or written record confirming this check has been carried out.
- Wind Management Policy: Weather is a significant risk factor for temporary structures. An effective wind management plan is essential for any event featuring TDS. This plan must:
- Detail the maximum safe wind speed for each individual structure.
- Outline a clear sequence of operations (e.g., lower banners, close the structure, or evacuate the area) at pre-determined wind speeds (e.g., at 60% and 80% of the maximum capacity).
- Identify a designated competent person on-site to continuously monitor wind conditions and implement the plan.
- Detail the maximum safe wind speed for each individual structure.
3. Operational Safety
During the event, organisers must maintain vigilance and ensure the public’s safety.
- Crowd and Load Management: The design of structures like stages and barriers must account for dynamic crowd loading. Crowd management plans should be in place to prevent overcrowding and manage crowd flow, especially in front of stages.
- Access and Egress: Temporary structures should not obstruct emergency exits or access routes for emergency services. Clear, safe pathways must be maintained at all times.
- Ongoing Checks: A competent person should conduct regular site checks of the structures, particularly in adverse weather conditions, to ensure all anchorages, bracing, and poles remain secure.
The Role of Guidance and Regulations
While a formal building control process for temporary structures is often not in place, there is a strong framework of guidance that organisers are expected to follow. Key resources include:
- The Institution of Structural Engineers (IStructE): Their guidance document, Temporary Demountable Structures: Guidance on procurement, design and use, is considered the industry standard.
- The Health and Safety Executive (HSE): The HSE’s event safety guidance, including resources on the Construction (Design and Management) Regulations 2015 (CDM 2015), applies to the construction and dismantling phases of temporary structures.
- Safety Advisory Groups (SAGs): Your local SAG will be a crucial point of contact. They will review your plans and may require detailed documentation and independent checks before granting a license for your event.
By prioritising competence, comprehensive planning, and ongoing vigilance, event organisers can ensure that temporary demountable structures are a safe and reliable component of a successful event.
For further information on Temporary Demountable Structures, you can visit the HSE’s website here.
