When you’re building a fence, the size and type of poles you use can make or break the project. Poles are the backbone of any fence. If they’re too small, untreated, or incorrectly installed, your fence won’t last.
As the saying goes, “Good fences make good neighbours.” A strong, well-built fence keeps peace on both sides of the property line, whether you’re securing livestock, protecting crops, or simply marking out your space. Choosing the right gum pole size ensures your fence stands strong against wind, animals, and time. It also prevents costly repairs or replacements down the line.
In this blog, we will discuss gum pole sizes for different types of fences and why the chosen sizes are ideal. We will also discuss some important factors that need to be considered to ensure a lasting fencing structure.
What are Treated Gum Poles?
Gum poles are made from Eucalyptus trees, a fast-growing and sustainable wood source. But raw gum poles on their own don’t last long in the ground. That’s why they’re treated with preservatives before being used for fences. Treatment protects gum poles from rot, insects, and moisture damage. This extends their life from just a few years to 15–20 years or more.
Understanding CCA Treatment
CCA stands for Chromated Copper Arsenic. It’s a treatment that penetrates deep into the wood to prevent fungus, termites, and rot.
- Copper protects against fungi.
- Chromium helps bind the chemicals into the wood.
- Arsenic provides resistance against insects and termites.
Hazard Class H3 and H4 Explained
Poles and timber are treated according to different hazard classes depending on the type of environments they will be exposed to. In this case, our gum poles are treated to these two hazard classes:
- H3 treatment for Droppers: Suitable for wood above ground but exposed to weather.
- H4 treatment for Building and Fencing Poles: Essential for poles that are installed in-ground.
Gum Pole Sizes for Different Types of Fences
Fence sizes differ as it depends on the purpose of installing the fence. Here are three main examples:
Fences for Security in Living Environments:
- Standard posts: 2.4m (75mm – 99mm): Strong enough for lighter-duty residential fences without being oversized.
- Corner posts: 2.4m (125mm – 149mm): Corners handle the most tension, so thicker poles keep the structure stable.
- Droppers: Usually not necessary: Urban fences don’t need extra reinforcement as there’s little pressure from animals.
These fences are about marking property boundaries or privacy, not containing livestock. Smaller poles are practical and cost-effective.
Game Fences: Recommended Gum Pole Sizes
- Standard posts: 3.6m (100mm – 124mm): Longer poles provide enough depth for tall fences that can withstand wildlife pushing against them.
- Corner posts: 3.6m (150mm – 174mm): Larger animals can put immense pressure on corners. Thick poles keep them upright.
- Droppers: 3m droppers used. Droppers spread pressure evenly and prevent wires from sagging.
Game fences must be tough enough to contain powerful wildlife like antelope or kudu. Bigger poles provide the strength and stability required.
Farm Fences: Recommended Gum Pole Sizes
- Standard posts: 2.1m (75mm – 99mm): Ideal for general farm fencing that doesn’t face extreme pressure.
- Corner posts & stays: 2.4m (100mm – 124mm): Slightly thicker to handle the extra pull from strung wires.
- Droppers: 1.5m droppers: Ensure wires stay evenly spaced and effective for controlling livestock.
Farm fences must balance durability with practicality. Using the correct pole sizes helps manage livestock without unnecessary costs.
Key Benefits of Using Treated Gum Poles
- Durability and Strength: Gum poles treated to H4 are built to last up to 20 years. You don’t want to rebuild a fence every 5 years. Long-lasting poles save money and time.
- Low Maintenance Requirements: No painting, staining, or sealing is needed. Once installed, treated gum poles require minimal upkeep, perfect for busy farmers or landowners.
- Resistant to Rust and Theft: Unlike steel, gum poles don’t rust. And unlike metal, they have no resale value as scrap. You’ll avoid replacement costs from theft or weather damage.
- Cost-Effective and Long-Lasting: The upfront investment pays off over decades of use. Gum poles give the best return on investment compared to untreated timber or metal alternatives.
Fire Safety and Vegetation Management
It’s recommended to keep at least 1 meter clear on both sides of the fence. Vegetation acts as fuel for fires, which can burn poles and damage galvanised wire. Clearing it reduces fire risk and keeps inspection routes open.
Firebreaks for Game and Farm Fencing
Firebreaks are mandatory in many regions. They not only prevent wildfires from spreading but also make it easier to patrol fences. A single wildfire can destroy kilometres of fencing. Firebreaks protect your investment and your livestock.
Conclusion
The success of any fence lies in choosing the right materials. Treated gum pole sizes for fences are carefully selected for urban, farm, and game applications because they offer the perfect mix of strength, durability, and cost-effectiveness.
From CCA treatment to proper firebreaks, every detail plays a role in ensuring your fence lasts decades. So whether you’re securing livestock, protecting crops, or marking boundaries, remember this simple truth: good fences really do make good neighbours.
Need more info or even a quote on our timber flooring products? Get in touch with Danie. We’re here to help you make the best timber choices for your project. Call/Whatsapp: 072 838 2838 or email: sales@sabietimber.co.za. We are always here to assist.
FAQs
1. What is the best gum pole size for urban fences?
2.4m poles (75mm – 99mm) are ideal, with larger 125mm – 149mm poles for corners.
2. How long do treated gum poles last?
On average, 15–20 years with proper treatment and fire safety practices.
3. What does H3 and H4 mean in CCA treatment?
H3 is for above-ground use, H4 for in-ground use. Posts should always be H4.
4. Do I need droppers for all fences?
Not for urban fences, but farm and game fences benefit greatly from droppers.
5. Are gum poles environmentally friendly?
Yes. Eucalyptus is renewable, and longer-lasting poles reduce waste.
