Yes, you absolutely can build your own steel garden edging using a welder — and it's one of the more rewarding weekend DIY projects for a handy homeowner. With the right materials, a basic welder, and some attention to safety, you can create durable, custom garden edging that will outlast most off-the-shelf options.
Is Welding Garden Edging Restricted Work in NZ?
Good news: welding steel garden edging is not restricted work under New Zealand law. Unlike electrical, gas, or plumbing work, general metal fabrication for garden use does not require a licence. However, you should still take safety seriously — welding produces intense UV light, heat, sparks, and fumes. Always follow safe practices (more on that below).
For guidance on what work is legally restricted in NZ, WorkSafe NZ is a great starting point.
Choosing the Right Steel
The most popular choices for DIY garden edging in NZ are:
| Steel Type | Pros | Cons |
|---|---|---|
| Mild steel (plain) | Cheap, easy to weld, widely available | Will rust unless treated or left to patina |
| Corten (weathering steel) | Develops a stable rust patina, very popular in NZ gardens | More expensive, harder to source |
| Galvanised steel | Rust-resistant | Releases toxic zinc fumes when welded — avoid welding |
| Stainless steel | Very durable, clean look | Expensive, requires specific filler wire and technique |
For most DIYers, mild steel flat bar (typically 3–5 mm thick, 50–100 mm wide) is the easiest and most cost-effective option. It welds cleanly and can be painted or left to develop a natural rust patina for a contemporary garden look.
Important: Never weld galvanised steel without specialist equipment and respiratory protection. The zinc coating releases toxic fumes that can cause serious illness. If you need galvanised edging, use mechanical fixings instead.
You can source flat bar steel from steel merchants and some larger hardware stores. Bunnings and Mitre 10 stock basic steel flat bar, or check a local steel supplier for better pricing on larger quantities.
What Welder Do You Need?
For steel garden edging, a MIG (GMAW) welder is the most beginner-friendly option. A basic 130–180 amp MIG welder running on standard 230V household power will handle 3–5 mm mild steel comfortably.
- MIG welding — easiest for beginners, clean welds, good for flat bar joins and corner brackets
- Stick (MMA) welding — more versatile outdoors, but harder to control on thin material
- TIG welding — produces beautiful welds but has a steep learning curve; not necessary for this project
If you don't own a welder, consider hiring one from a local hire centre, or check if a friend or neighbour has one you can borrow.
Planning Your Garden Edging
Before you strike an arc, plan your design:
- Measure your garden beds carefully and sketch out the layout
- Decide on height — 100 mm is common for a clean edge, 150–200 mm for a raised look
- Plan your corner joins — mitre cuts at 45° give a neat finish; right-angle butt joins are simpler
- Consider stakes or pegs welded to the back of the edging to anchor it into the ground (flat bar offcuts work well)
Step-by-Step: Basic Welding Process
- Cut your steel to length using an angle grinder with a cutting disc or a metal drop saw
- Clean the steel — remove mill scale, rust, and oil with a wire brush or flap disc
- Tack weld pieces together first to check alignment before running full welds
- Weld your joins — for corner joints, a simple fillet weld on the inside face is strong and tidy
- Grind welds smooth if you want a clean finish
- Treat the steel — apply a rust-inhibiting primer and paint, or leave mild steel to rust naturally for a Corten-style look. Resene and Dulux both offer suitable metal primers and topcoats
Safety — Don't Skip This
Welding carries real risks. Before you start:
- Eye protection: Always wear a proper auto-darkening welding helmet (minimum shade 10 for MIG). Never look at the arc without protection — even a brief glance can cause arc eye
- Protective clothing: Leather gloves, long sleeves, and leather boots. Sparks travel further than you think
- Ventilation: Weld outdoors or in a very well-ventilated space. Welding fumes are hazardous
- Fire safety: Clear the area of flammable materials. Keep a fire extinguisher nearby
- Electrical safety: Ensure your welder is properly earthed and leads are in good condition
Refer to WorkSafe NZ for detailed guidance on safe welding practices.
Finishing and Installation
Once your edging sections are fabricated:
- Prime and paint with a quality metal primer followed by an exterior topcoat, or apply a clear rust-inhibiting oil if you want a natural patina
- Install by driving the stakes into the ground with a rubber mallet
- For curved beds, you can score the back of flat bar with an angle grinder at intervals to allow gentle bending, or use thinner 2–3 mm steel which flexes more easily
When to Call a Professional
While garden edging is well within reach of a capable DIYer, consider hiring a professional welder if:
- You've never welded before and don't have access to training or a mentor
- Your project involves complex curves, large quantities, or structural elements
- You want a polished, professional finish for a high-visibility garden feature
- You need to work with stainless steel or other specialist materials
A qualified welder can knock out custom garden edging efficiently and to a high standard. You can find experienced local welders and fabricators on tradedirectory.co.nz.
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