Improve Anchorage of Detached Structures

07/31/2025

Why do they matter?

Many homes have accessory structures such as sheds, gazebos, pavilions, pergolas, and attached structures such as open carports. An accessory structure can be damaged and moved by high winds if it is not tied down securely.

Post-storm engineering analysis after high-wind events often finds damage caused by the failure of an attached or accessory structure to the home. Carports with insufficient connections to the home can be lifted by high winds. Other accessory structures, such as sheds, can become windborne debris when lacking proper anchorage. Don’t let these structures become a hazard to the safety of your home and your neighbors.

What do I need to know?

• Outdoor covered structures are usually supported by horizontal beam members sitting on vertical columns. Columns should be securely connected to the foundation to prevent uplift and wind damage.
• Carports and other attached structures, such as swimming pool screen enclosures, must be securely anchored to a foundation and attached to the main structure.
• All accessory items require some form of anchorage regardless of size. Even a small playhouse can detach and become windborne debris in extreme wind events. Generally, if the object cannot be moved indoors, it should be anchored to the ground.

Where do I start?

• Securely anchor all storage sheds and outbuildings to a permanent foundation or with straps and ground anchors used for manufactured homes.

Discover technical details:

• Consult a contractor or engineer in your area to have them determine if the anchorage and connections on your accessory or attached structures are sufficient to resist high-wind events.

More Resources:

• FLASH. Resilient Design Guide: High Wind Wood Frame Construction Edition.
• FLASH. Resilient Design Guide: Concrete Construction Edition.
• FEMA. Remove Trees and Potential Windborne Missiles.