Building a basic timber gate is a rewarding weekend project that most handy homeowners can tackle with standard tools and a bit of patience. The key to a gate that swings true and lasts for years is solid framing, a proper diagonal brace, and well-set posts. Here's how to do it right.
Plan Before You Build
Before cutting a single piece of timber, measure your opening width carefully — measure at the top, middle, and bottom, as fence posts can lean slightly. A good rule of thumb is to allow a 10–15 mm clearance on each side of the gate so it swings freely without binding. Decide on your gate height (typically matching your fence height) and whether the gate will swing inward or outward.
Also consider whether your project needs a building consent. Most residential fences and gates under 1.5 m high are exempt under Schedule 1 of the Building Act, but rules vary — always confirm with your local council before starting. You can find guidance at MBIE Building Performance.
Materials You'll Need
For a standard timber paling gate, you'll typically need:
- Framing timber: 75 × 50 mm H3.2 treated pine for the frame (H3.2 is suitable for above-ground exterior use)
- Palings or boards: to match your existing fence
- One diagonal brace: same framing timber, running from the bottom hinge corner to the top latch corner
- Galvanised or stainless steel hardware: hinges (heavy-duty tee or butt hinges), a latch or bolt, and screws/bolts
- Exterior wood glue (optional, for extra joint strength)
- Post-mix concrete if you're setting new gate posts
You'll find treated timber, hardware, and post-mix concrete at Bunnings, Mitre 10, or PlaceMakers.
Step 1 — Set Solid Gate Posts
A gate is only as good as its posts. Gate posts should be larger and deeper than standard fence posts — 100 × 100 mm is common for a typical garden gate. Set them at least 600 mm into the ground (deeper in soft or clay soils), plumb them carefully with a spirit level, and pack with post-mix concrete. Allow the concrete to cure for at least 24–48 hours before hanging the gate.
Step 2 — Build the Gate Frame
Cut your framing timber to form a rectangular frame sized to your opening (minus clearance gaps). Join the corners using half-lap joints or simple butt joints secured with galvanised coach screws. A basic frame has:
- Two vertical stiles (the sides)
- A top and bottom rail
- A mid-rail if the gate is taller than about 1.2 m
Lay the frame flat on a level surface while assembling — this helps keep everything square. Check squareness by measuring the diagonals: if both diagonal measurements are equal, your frame is square.
Step 3 — Add the Diagonal Brace
This is the most important structural step. Without a diagonal brace, timber gates will sag over time. The brace must run from the bottom hinge corner up to the top latch corner — this direction puts the brace in compression and counteracts the weight of the gate.
Mark and cut the brace to fit snugly between the rails, then fix it with galvanised screws or bolts. Some builders also use a steel tension rod (threaded rod with turnbuckle) as an alternative or supplement.
Step 4 — Fix the Palings or Boards
With the frame braced and square, fix your palings or boards to the front face. Work from one side to the other, keeping consistent spacing. Use two galvanised nails or screws per paling at each rail to prevent twisting. If you're matching an existing fence, try to replicate the paling width and spacing as closely as possible.
Step 5 — Hang the Gate
Fit your hinges to the gate first, then hold the gate in position (use timber offcuts as spacers to maintain your clearance gaps) and mark the hinge positions on the post. Use three hinges for heavier or taller gates. Make sure the gate is level before driving the final screws.
| Gate Width | Recommended Hinges | Hinge Size (guide) |
|---|---|---|
| Up to 900 mm | 2 hinges | 100 mm tee hinge |
| 900–1200 mm | 2–3 hinges | 150 mm tee hinge |
| Over 1200 mm | 3 hinges | Heavy-duty butt or strap |
Fit your latch or bolt on the opposite stile at a comfortable height. For child-safety around pools, check your local council requirements — pool gates have specific self-closing and self-latching requirements under the Fencing of Swimming Pools Act 1987.
Step 6 — Finish and Protect the Timber
Unpainted or unsealed timber will weather and deteriorate quickly in the NZ climate. Apply a quality exterior primer and paint or a timber stain and sealer to all surfaces, including end grain. Resene, Dulux, and Wattyl all offer exterior timber coating systems suited to NZ conditions. Pay particular attention to end grain cuts, which absorb moisture readily.
When to Call a Professional
Most timber gate builds are well within DIY reach, but consider hiring a qualified carpenter if:
- Your gate opening is large or the gate is particularly heavy
- The existing posts are rotten or poorly set and need replacing
- You need to work near electrical lines or underground services
- The gate is part of a pool fence (compliance is critical — errors can have serious safety and legal consequences)
A licensed carpenter can also advise on the best timber species and hardware for your specific situation. You can find experienced local carpenters on tradedirectory.co.nz.
For any work near electrical infrastructure, always contact your lines company and refer to WorkSafe NZ guidelines.