Quick Answer
When choosing between concrete and gravel footings for a solar ground mount pole, consider the weight and size of the equipment, soil stability, and local building codes. Concrete footings provide a solid foundation for heavy solar arrays, while gravel footings are suitable for smaller systems. Consult local experts to determine the best option.
Choosing the Right Footing Material
When deciding between concrete and gravel footings, the weight and size of the solar equipment are crucial factors. A heavy solar array, typically over 5 kW, requires a concrete footing to distribute the weight evenly and prevent settlement or collapse. For smaller systems, typically under 3 kW, a gravel footing can be sufficient. However, if the soil is unstable or prone to flooding, a concrete footing is still the recommended choice.
Designing the Footing System
For concrete footings, the design should include a 12-inch deep foundation with a 18-inch wide base to accommodate the weight of the solar array and wind loads. A 4-inch thick slab is recommended to prevent cracks and ensure a solid base. When using gravel footings, a 2-inch thick layer of compacted gravel is sufficient, but it’s essential to check the local building codes for specific requirements. A 12-inch deep footing is still recommended to ensure stability.
Installation and Setup
Regardless of the footing material, it’s essential to follow the manufacturer’s instructions for installation and setup. For concrete footings, the concrete should be poured in a well-ventilated area, and the footing should be allowed to cure for at least 24 hours before loading. For gravel footings, the gravel should be compacted using a plate compactor to prevent settling. Always consult local experts and follow building codes to ensure a safe and secure installation.
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