Joining two fence panels at a corner is one of the most important parts of any fencing job — get it right and your fence will be solid and square for years; get it wrong and you'll end up with a wobbly, leaning eyesore. The good news is that with the right post, the right fixings, and a bit of care, it's a very achievable DIY project for most homeowners.
Why the Corner Post Is Everything
The secret to a strong corner join is almost always the corner post itself. A corner post needs to handle lateral forces from two directions at once, so it must be:
- Larger than your line posts — for a standard 1.8 m timber paling fence, a 100 × 100 mm post is the minimum recommended size at corners
- Set deeper in the ground — aim for at least one-third of the total post length buried, with a concrete footing for stability
- Plumb in both directions — use a spirit level on two adjacent faces before the concrete sets
If your corner post isn't solid, no amount of clever joinery will save you.
The Two Main Corner Configurations
90-Degree (Right-Angle) Corner
This is the most common situation — two fence lines meeting at a right angle, such as at the corner of a section boundary.
Method 1: Single corner post with panels fixed to adjacent faces
This is the simplest and most popular approach:
- Set a 100 × 100 mm (or larger) timber or steel post at the corner.
- Fix one panel (or the rails of one fence run) to one face of the post.
- Fix the second panel to the adjacent face, at 90 degrees.
- Use galvanised coach screws (M10 × 75 mm is a common size) or joist hanger nails for timber-to-timber connections — never use plain steel fixings outdoors as they will rust and stain.
This method works well for timber paling, lapped-and-capped, and pre-made panel fences.
Method 2: Two posts set close together
Some fencers prefer to set two posts very close together (50–75 mm apart) at the corner, one for each fence run. Each panel then terminates cleanly on its own post. This makes future repairs easier and avoids the need to fix into the narrow edge of a post.
Angled or Obtuse Corners
If your boundary doesn't meet at 90 degrees, you have a couple of options:
- Cut the post at the bisecting angle so both fence runs sit flush against it — this requires accurate measuring and a drop saw or circular saw with a bevel guide.
- Use two posts set at the required angle, one for each run — often the easier DIY option.
Fixing Methods and Hardware
Choosing the right fixings is critical in the NZ climate, especially in coastal or high-rainfall areas.
| Fixing Type | Best For | NZ Tip |
|---|---|---|
| Hot-dipped galvanised coach screws | Timber post to timber rail | Minimum G300 galvanising for exposed use |
| Stainless steel screws | Coastal areas within 500 m of the sea | Worth the extra cost to avoid rust staining |
| Galvanised post brackets / stirrups | Steel posts with timber rails | Check manufacturer's load ratings |
| Tek screws (self-drilling) | Steel-framed panels to steel posts | Use the correct drill bit size |
For pre-made panel fences (such as Colorbond-style or aluminium slat panels), the manufacturer will usually supply proprietary corner brackets or specify a compatible post system — always follow their instructions.
Timber Treatment and Weatherproofing
All timber used in ground contact or exposed to the weather must be treated to the correct hazard class under NZS 3640. For fence posts in ground contact, you need H5 treated timber (e.g. CCA or equivalent). Rails and palings above ground typically require H3.2 treatment.
Once your corner is assembled, seal any cut ends with an appropriate timber preservative end-grain sealer, and consider painting or staining exposed timber with a quality exterior product from Resene or Dulux to extend its life.
Does Your Fence Need a Building Consent?
In most cases, residential boundary fences up to 2.0 m high are exempt from building consent under Schedule 1 of the Building Act 2004 — but this depends on your specific situation, including proximity to a boundary, retaining walls, and local district plan rules. Always check with your local council before starting, as rules vary. You can find general guidance at MBIE Building Performance.
Also be aware of the Fencing Act 1978, which governs cost-sharing with neighbours for boundary fences — worth a conversation with your neighbour before you start.
Tips for a Neat, Professional Finish
- Use a string line to keep both fence runs straight as they approach the corner
- Check the corner is square with a builder's square or the 3-4-5 triangle method before fixing
- Pre-drill timber to avoid splitting, especially near post ends
- Leave a small gap (2–3 mm) between palings and the ground to prevent moisture wicking
When to Call a Professional
If your corner involves a retaining wall, a fence over 2.0 m high, or sits on a steep or unstable slope, it's well worth getting a qualified fencer involved. A professional will ensure the post footings are adequate, the fence complies with the NZ Building Code, and the finished result is safe and durable. You can find experienced local fencers on tradedirectory.co.nz.
Note: Fencing itself is not restricted trade work, but if your project involves any electrical (e.g. electric fence energisers connected to mains power) or plumbing work, those elements must be carried out by a licensed professional — see EWRB and PGDB for details.
