Understanding the differences between tapered wooden poles and cylindrical/machine-turned poles can help you make sustainable choices for future building.
Although both types of poles may seem to serve similar purposes, there are quite a lot going on behind the scenes. In our discussion, we will focus on SA Pine Poles and Eucalyptus Grandis Poles, as these wood types are commonly utilized in South Africa.
Let’s start by exploring the distinctions between Pine and Eucalyptus, delving into the variations in their manufacturing processes, and examining the advantages and disadvantages associated with each wood type.
Understanding the differences between Pine and Eucalyptus
Each wood type boasts a unique set of characteristics, ranging from fiber composition and growth rates to strength and color.
- Fiber Composition and Texture:
- Pine: Exhibits a straight grain and fine texture with relatively soft fibers.
- Eucalyptus: Characterized by an interlocked grain and a moderately coarse texture, providing a distinct tactile experience.
- Sapwood-to-Heartwood Ratio:
- Pine: Typically displays a larger proportion of sapwood.
- Eucalyptus: Showcases a relatively larger heartwood size. This ratio contributes to aesthetic differences and influences the wood’s durability and resistance to decay.
- Growth Rates:
- Pine: Grows at a moderate pace.
- Eucalyptus: Demonstrates significantly faster growth rates, surpassing Pine by at least three times. a 12-year-old Eucalyptus tree can match the size of a 32-year-old Pine tree, highlighting the rapid maturation of Eucalyptus.
- Pine: Strikes a balance between stiffness and flexibility, offering moderate strength.
- Eucalyptus: Known for its hardness and density, presenting a sturdier composition.
- Pine: Exhibits a lighter color, often featuring pale yellows or whites.
- Eucalyptus: Displays a diverse range of colors, including reddish-browns, grays, and whites, contributing to a varied and distinctive appearance.
4 Main differences between Pine turned Wooden Poles and Eucalyptus wooden poles
Now that you have gained insight into the distinctions between the two types, let’s delve deeper and explore them as contrasting poles.
Pine turned Poles: Pine turned poles boast a flawless cylindrical shape, maintaining uniformity from top to bottom and may not show any visible cracks. The meticulous turning process imparts a polished and smooth surface, enhancing their aesthetic appeal.
The evenness of their form contributes to a sleek and modern appearance, making them well-suited for various applications where a clean and refined look is desired. The natural grain patterns of Pine may also be showcased on the surface, adding a touch of warmth and character. This consistency in shape and texture allows for a versatile and elegant visual presentation in a wide range of settings.
Eucalyptus poles: They exhibit a tapered design, characterized by a gradual reduction in diameter or thickness from one end to the other. You may find visible cracks in the poles, however, it does not effect its strength at all. The inherent hardness and density of Eucalyptus wood make it challenging to turn using traditional methods. The result is a naturally tapered shape that highlights the raw and authentic appearance of these poles.
The rugged and unrefined aesthetic of Eucalyptus poles adds a unique charm, showcasing the distinct characteristics of the hardwood. This natural look not only provides a connection to the authenticity of the material but also makes Eucalyptus poles particularly well-suited for environments where a more rustic or organic visual appeal is desired.
The variation in diameter adds a dynamic quality, allowing these poles to seamlessly integrate into outdoor landscapes or architectural designs, where the irregularities contribute to their overall visual interest.
Pine Poles: The timber processing journey begins with the initial stages of harvesting, followed by a meticulous inspection and the removal of bark from the poles. Subsequently, the poles are methodically stacked and left to undergo a thorough air-drying process for approximately one year. Once the moisture content of the wood drops below 28%, indicating optimal dryness, the poles are deemed ready for the crucial impregnation phase.
In preparation for impregnation, a precision step involves turning off 3-5 mm of the surface wood to eliminate resins and achieve a refined surface finish and the poles are cut in uniform lengths. Wood turning lathes are used to shape the wood into cylindrical profiles.
Post-turning, the wood undergoes a treatment phase to enhance its durability and resistance. Following treatment, a comprehensive inspection is conducted to ensure that the poles have been appropriately treated, meeting the required quality standards.
Eucalyptus Poles: Similar to Pine poles, Eucalyptus poles undergo a harvesting process where bark is removed. These freshly harvested poles are allowed to remain in their natural state for an approximate duration of two weeks, enabling the escape of moisture and the settling of cellulose. This natural curing period contributes to the overall stability and quality of the wood. After two weeks, when the poles have attained the desired moisture content, a meticulous grading process takes place.
The poles are carefully examined and categorized based on various criteria, ensuring that each one meets specific quality standards. Subsequently, precision cutting is employed to achieve uniform lengths. The poles are then ready for treatment.
Durability and applications
Pine and Eucalyptus poles can be highly durable if used in the correct applications and if treated properly. However, their applications differ.
Pine Poles: With the outer layer of the poles being removed in the manufacturing process, their strength is compromised. They are therefore also not strength-graded according to the South African National Standards (SANS). These poles are best suited for only specific structural purposes, but they can still be used in applications like fences, roofs, and jungle gyms and furniture provided that the reduced strength is considered.
Eucalyptus poles: In their natural state, these poles are deemed as very strong, they are graded for strength according to SANS standards and can therefore be used for construction purposes where heavy load-bearing support is required in building frameworks. They can also be used in applications such as fencing posts, garden edging, etc.
Eucalyptus poles and turned Pine poles each have their strengths, but when it comes to sustainability, Eucalyptus holds an advantage.
This is mainly because Eucalyptus trees grow faster and require less energy in the production process. The speedy growth of Eucalyptus trees plays a key role en environmental sustainability. They mature quickly compared to softwoods like Pine, allowing for more frequent harvesting and faster resource replenishment. This faster growth contributes to a lower overall environmental impact associated with obtaining raw materials.
Keep this in mind…
When buying Eucalyptus poles, it’s essential to note a key difference compared to Pine turned poles. While you can easily specify the exact diameter you want for a Pine turned pole, it is different with Eucalyptus tapered poles. This is because they come in diameter classes.
For instance, if you’re looking for a 50mm diameter pole, it falls within the 50mm – 74mm diameter class for Eucalyptus poles. It’s crucial to understand that only the top side of these poles are measured. So, even though the top side may be around 50mm, the bottom part’s diameter could be slightly larger. This variation is a distinctive feature of Eucalyptus poles compared to the more uniform dimensions of Pine poles.
At Sabie Poles we supply Eucalyptus CCA treated poles. We believe is only supplying top-quality poles that are strong and durable and that are able to handle the heavy work.