Greenhouse Structure
Light galvanized frames for agricultural greenhouses.
Overview
Greenhouse frames work in constant humidity, often with fertilizers and frequent condensation, yet they have to stay economical across large areas. Light galvanized round and square tube is the most common solution for arches, columns and purlins.
Wall thickness is the main cost driver, so it is usually kept as light as the design permits. That makes coating quality, straightness and consistent sizes especially important, as they affect both the service life and the speed of assembly.
Where each steel product is used
| Structure | Steel product | Typical grades / standards |
|---|---|---|
| Arches and columns | Galvanized round pipe | Q195 / Q235, GB/T 3091 |
| Frames and purlins | Galvanized square tube | Q195 / Q235, Z120–Z275 |
| Frames in more humid conditions | ZAM tube | JIS G3323 / EN 10346 |
| Gutters and purlins | C-purlin | DX51D / S350GD, Z275 |
Grades shown are typical examples. The project's design documents and applicable codes decide the final specification.
Common standards: GB/T 3091, EN 10255, ASTM A53
What the project needs
- Hot-dip or pre-galvanized tube for humid conditions
- Light wall thickness to control cost
- Bent and punched parts to drawing
What to consider when selecting steel
Coating choice
Pre-galvanized tube suits many frames at a lower cost, while hot-dip galvanizing gives a thicker coating for harsher conditions. Ask for the coating mass, not just the word 'galvanized'.
Light wall sections
Thin walls bend and deform more easily, so check the wind and snow loads in the design before reducing thickness.
Bending and punching
Arches and connectors can be bent and punched to drawing. Damaged coating at welds and cuts should be repaired to protect these points.
Recommended products
What to include in your inquiry
- Tube size, wall thickness, length and coating mass
- Drawings for bent or punched parts
- Local wind and snow design loads
- Bundle size and container loading plan
Frequently asked questions
Should greenhouse tube be pre-galvanized or hot-dip galvanized?
It depends on budget and humidity. Hot-dip galvanizing gives a thicker coating, while pre-galvanized tube is often more economical for lighter frames.
Is thinner tube always cheaper?
Per ton of steel it can reduce total weight, but thinner walls must still meet wind and snow loads. The design should confirm the minimum thickness.
Can arches be supplied already bent?
Bent parts can be requested to drawing. Check how bent parts will be packed, since they take more container space than straight tube.