When choosing the diameter of the pipe for the greenhouse arch, what factors should be taken into consideration?

When choosing the diameter of the arch support tubes for a home greenhouse, multiple factors need to be systematically considered. The core of this is to find the great balance among safety, durability and cost.

1. Geographical location and climatic conditions (Most important!)
This is the primary basis for choosing the pipe diameter and wall thickness.

Wind Load:

• Wind-prone areas (coastal, plains, mountainous regions): Greater wind resistance is required. The wind will cause uplift and shear forces on the greenhouse. Therefore, it is necessary to select thicker and wider pipes (for example: Φ32mm x 1.2mm).
• Windless areas (inland, urban courtyards): The requirements can be appropriately lowered, but still need to meet the basic safety standards.

Snow Load:

• Snowy areas: The accumulated snow acts as a significant static pressure, which may directly collapse the greenhouse. The pipe diameter and wall thickness must be strengthened, and a round-arch roof (which facilitates the sliding of snow) should be preferred over a flat roof.
• Snow-free areas: The main concern is the issue of wind resistance.

2. Dimensions and Span of the Greenhouse

• Span (Width): This is the very direct influencing factor. The larger the span, the higher the strength requirements for the arch members.  ≤ 4 meters span: Consider using a pipe diameter of Φ25mm.  4-meter span: It is strongly recommended to use pipes with a diameter of 32mm or larger.
• Height: An increase in height will enlarge the wind exposure area and thus require a stronger structure.
• Length (Length): The length has little impact, but the longer greenhouse requires a greater number of longitudinal braces to ensure overall stability.

3. Types of covering materials

The weight of the covering material is directly borne by the arch beam.

• Glass: The heaviest, therefore a very sturdy frame must be used (such as 40x40mm square tubes with a wall thickness of ≥ 1.5mm).
• PC solar panel / endurance board: Medium weight. Requires precision and strength of the frame (recommended: Φ32mm x 1.0mm or above).
• Plastic film: The lightest in weight, exerting the least pressure on the framework. The choice is mainly based on considerations of resisting snowstorms.

4. Steel material and anti-corrosion process (affects lifespan)

• Material: Prefer galvanized steel. Absolutely avoid using ordinary carbon steel that is prone to rust (even painted steel is not acceptable).
• Surface treatment (sorted by durability):

     Hot-Dip Galvanized: The great choice. The zinc coating is thick, with strong corrosion resistance, and the service life can reach 10-15 years. It is a must-have for outdoor use.
     Electro-galvanizing: The zinc layer is thin, has moderate rust prevention ability, has a short lifespan, and is not recommended.
     Painting / Applying anti-rust paint: The anti-rust effect is the poorest. Regular maintenance is required. It can generally be used once.