There’s a common misconception that leaving the sides of a marquee off makes it more wind-resistant because it allows the wind to “pass through.” However, this idea is incorrect. In fact, leaving the sides off makes the marquee far more vulnerable to wind damage. Let me explain why keeping the sides on is the safer option when facing strong winds.
Wind and Marquee Dynamics
As illustrated in the diagram, when wind hits a marquee with its sides on, it flows over and around the structure. Any wind that does enter the marquee collects underneath the roof and causes upward pressure, potentially lifting the roof. The best way to prevent this is to ensure the sides of the marquee, particularly those facing the wind, are in place and the marquee is securely anchored to the ground.
It’s important to note that this advice applies to strong winds but not extreme weather conditions. Marquees should never be left up in dangerous weather.
The False Logic of Removing the Sides
Those who suggest removing the side panels in strong winds believe it will allow the wind to pass through harmlessly. Unfortunately, this is not the case. Two major factors come into play when the sides are left off:
- Wind Still Accumulates Under the Roof: Even with the sides removed, wind will continue to gather beneath the roof. Think of it like carrying an umbrella in a windy field—the wind will still catch the umbrella and push it upwards. In this scenario, your marquee is essentially a giant umbrella.
- Lift Created by Wind Passing Through: As wind flows over or through the marquee, a lifting effect is generated. This is similar to the way lift is created by an airplane wing. The wind traveling over the top of the marquee moves faster than the wind below, creating a pressure difference that results in lift. While a marquee roof isn’t shaped like an airplane wing, it still experiences lift, and the steeper the roof, the greater the force. This is especially true for marquees with steeper roofs, like those with a 20-degree slope and 3-meter apex, as we discussed previously.
Best Practices for Marquee Safety
This article isn’t meant to alarm anyone but to clear up the misunderstanding about leaving sides off marquees in windy conditions. At DIY Marquees, we always encourage best practices for marquee hire companies. Here are a few key recommendations:
- Anchor your marquee securely: Use tie-down kits as a minimum standard.
- Keep the sides on: Especially on the side facing the wind. Place the entrance on a different side, if possible.
- Never remove all the sides during strong winds: Doing so makes the structure far more vulnerable.
- Understand your marquee’s limitations: If extreme weather is forecast, like a hurricane, the marquee should come down. Fortunately, these situations are rare.
Thank you for reading, and as always, we welcome any feedback.
— Spencer
