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When it comes to building a greenhouse, the structure’s performance depends heavily on the quality and design of its arches. Among the available options, the Oval tube stands out as the best solution, offering the perfect balance between strength, durability, and efficiency.
Here’s why:
1. Superior Structural Resistance
The unique oval shape of the Oval tube provides enhanced resistance to bending and deformation compared to traditional round or square tubes. Its aerodynamic profile allows it to better withstand wind and snow loads, ensuring the stability and safety of the greenhouse.
Thanks to this increased strength, the overall structure remains solid and reliable even under challenging weather conditions.
2. Steel is better distributed = More Light
One of the key advantages of the Oval tube is its ability to deliver greater strength with less material. Because the profile is naturally more resistant, arches can be installed with wider spacing between them without compromising stability.
This means fewer structural elements obstructing sunlight, allowing more natural light to reach the plants. Better light penetration boosts photosynthesis, leading to healthier, faster-growing crops while also helping you reduce energy costs if supplemental lighting is used.
Most head growers and experts say that 1% more light in a greenhouse leads to about 1% more yield.
Corenthin Chassouant, agronomist (MSC), greenhouse expert and Horti-Generation author
Optimizing the use of steel also makes greenhouse installation easier, as the arches can be spaced farther apart, which helps reduce installation costs.
3. Long-Lasting Durability
Oval tubes are designed for long-term performance. Their structure resists twisting, sagging, and premature wear, which significantly reduces the need for maintenance or replacements over time.
Combined with high-quality galvanization (Galvalume for example), they offer excellent protection against corrosion, ensuring your greenhouse remains efficient and operational for years.
4. Gentle on the Poly Cover (no edges!)
Unlike square, rectangular or sharp-edged profiles, the Oval tube features smooth, rounded surfaces that are gentler on the greenhouse film. This design minimizes friction and stress points, preventing premature tearing or damage to the poly cover.
The result: longer-lasting coverings and reduced replacement costs, which means more savings in the long run.
5. Stronger than the other types (for the same quantity of steel!)
Oval tubing’s wider, flatter profile boosts bending stiffness. It reduces deformation compared to equal-weight round, square, or rectangular tubes, making arches stronger, more stable, and more material-efficient for commercial greenhouse structures (J huete Greenhouses, 2025)
In short, for the same quantity of steel, the Oval tube is almost 50% stronger (elastic limit) than the square, 30% stronger than round tubes and 20% stronger than the rectangular arches.
Conclusion
The Oval tube offers the perfect combination of strength, efficiency, and durability, making it the ideal solution for greenhouse arches. By allowing wider spacing between arches, it maximises light penetration for better plant growth while maintaining a highly resistant structure. It will also make the whole greenhouse installation less expensive, thanks to the wider spacing between arches.
On top of that, its smooth profile protects the greenhouse film (poly), reducing friction and extending the lifespan of the entire installation.
If you’re looking for a brighter, stronger, and more efficient solution for your greenhouse, the Oval tube is the clear winner.
Harnois Greenhouses, as an example, is well known for using Oval tubes for its greenhouse products range: TunnelPro Plus, Ovaltech freestanding and the Luminosa gutter connected or multi-span greenhouses.
