Whether you're putting up a residential fence, a rural boundary line, or a commercial security barrier, post hole digging is the foundation, literally, of any successful fencing project. But how deep should those holes go? What tools or techniques should you use? And are there any laws you need to be aware of before you start digging?
Here's a practical guide to help you get your post hole digging done safely, accurately, and in line with Queensland requirements.
Common Methods of Post Hole Digging
- Manual Post Hole Diggers (Clamshell Diggers): These handheld tools are ideal for small-scale projects and softer soils. They're labor-intensive but cost-effective for a few holes.
- Augers (Manual or Powered): Augers are corkscrew-like tools that bore into the ground. They can be manual for shallow holes and light-duty projects or petrol-powered or hydraulic for deeper, faster, and more efficient digging in compacted soils or rocky terrain.
- Vacuum Excavation: For sensitive areas where underground utilities might be present or when clean, non-destructive holes are needed, vacuum excavation offers a precise, safe alternative. It uses high-pressure air or water to break up soil, which is then vacuumed out.
How Deep Should Fence Post Holes Be?
When digging post holes, the general rule of thumb is one-third of the post's total length should be below ground. For example, a 1.8m high fence post would need to be buried at least 600mm deep.
It is also important to consider soil stability, post load (heavy gates etc.) and local weather exposure. For example, in windy or sandy areas, deeper holes and concrete footings may be required.
Queensland Laws and Regulations
- Boundary Fences (Neighbourhood Disputes Act 2011):
- Must be built on the common boundary unless agreed otherwise.
- Shared fencing costs are typically split 50/50 between neighbours.
- Fencing Height Rules:
- Residential fences facing the street are usually limited to 1.2m high.
- Side and rear fences can be up to 2m without council approval. Anything higher often requires development approval from your local council.
- Underground Asset Protection:
- You are legally required to contact Before You Dig Australia to check for underground assets before any excavation.
- Vacuum excavation is recommended or required in many areas when digging near known utilities.
Cutting corners with post holes can lead to leaning or collapsing fences, damage to underground utilities, legal issues with councils or neighbours and costly repairs or re-digging. Using the right method and staying compliant saves time, money, and headaches in the long run.
Whether it's a backyard fence or a large-scale boundary line, Vac to the Future can help you start strong, right from the first hole.