Building a brick barbecue is a satisfying weekend project that adds real value to your outdoor living space. With basic bricklaying skills, the right materials, and a bit of planning, most NZ homeowners can tackle a simple freestanding BBQ. Here's how to do it safely and correctly.
Do You Need a Building Consent?
In most cases, a small freestanding brick barbecue does not require a building consent under Schedule 1 of the Building Act 2004 — but this depends on its size, location, and your local council's rules. As a general guide, a low, freestanding outdoor BBQ structure that is not attached to your home and has no roof is typically exempt. However, rules vary between councils, so always check with your local council before you start. You can find general guidance on exemptions at MBIE Building Performance.
Also note: if you plan to connect a gas line to your BBQ, that work is restricted to a licensed gasfitter registered with the Plumbers, Gasfitters and Drainlayers Board. Never attempt gas connections yourself.
Planning Your BBQ Design
Before buying materials, decide on:
- Size — A cooking area of around 600 mm × 400 mm suits most families.
- Height — A comfortable cooking height is typically 800–900 mm from ground level.
- Location — Site your BBQ at least 1 metre from fences, overhanging trees, and structures. Check your local council's rules on open fires and outdoor cooking structures.
- Orientation — Position it so prevailing winds carry smoke away from your home and neighbours.
Sketch a simple plan and count your bricks before heading to the hardware store.
Materials You'll Need
| Item | Notes |
|---|---|
| Solid clay or concrete bricks | Avoid hollow bricks — they can crack under heat |
| Fire bricks (for the firebox) | Rated to withstand high temperatures |
| Refractory mortar | For the inner firebox; standard mortar can crack |
| Standard mortar mix | For outer walls (cement, sand, water) |
| Concrete mix | For the foundation slab |
| Steel grill grates | Sized to fit your opening |
| Steel angle iron or flat bar | To support grates and ash tray |
| Builders' line and spirit level | For keeping courses straight |
| Trowel, jointing tool, rubber mallet | Basic bricklaying tools |
You'll find bricks, mortar, and tools at Bunnings, Mitre 10, or PlaceMakers.
Step 1 — Lay a Solid Concrete Foundation
A stable base is critical. Dig out a level area at least 100 mm deep and slightly larger than your BBQ footprint. Pour a concrete slab at least 100 mm thick and allow it to cure for a minimum of 48 hours (longer in cold or wet NZ weather) before laying any bricks. A weak or uneven slab will cause your BBQ to crack and shift over time.
Step 2 — Dry-Lay Your First Course
Before mixing any mortar, dry-lay your first course of bricks to check your layout and spacing. Standard brickwork uses a 10 mm mortar joint. Mark the outline on your slab with chalk or a pencil.
Step 3 — Mix Your Mortar
For the outer walls, mix a standard mortar: roughly 1 part cement to 4–5 parts sand, adding water gradually until you reach a firm, workable consistency. For the inner firebox walls, use a refractory (fire-rated) mortar — available from specialist masonry suppliers — as standard mortar will crack under repeated high heat.
Step 4 — Lay the Bricks
- Spread mortar on the slab and lay your first course, checking it is level and square with a spirit level and set square.
- Stagger the joints (running bond pattern) on each course for strength — never stack joints directly on top of each other.
- Use a rubber mallet to tap bricks gently into position.
- Check for level and plumb every two or three courses.
- Build up the side walls, leaving gaps at the appropriate heights to insert steel angle iron supports for your grill grates and ash tray.
- Use fire bricks and refractory mortar for the inner firebox area from the base up to grill height.
Step 5 — Install Grate Supports
Embed steel angle iron into the mortar joints at the heights you want for your ash tray and cooking grate. A typical setup has one level for an ash tray and one or two levels for grates at different heights, giving you heat control.
Step 6 — Finishing and Curing
Once all courses are laid, point the joints neatly with a jointing tool for a tidy, weather-resistant finish. Allow the mortar to cure slowly — keep it damp and shaded for the first few days, especially in hot NZ summer conditions. Don't light your first fire for at least 7 days. When you do, start with a small fire to cure the refractory mortar gradually before cooking at full heat.
Safety Tips
- Keep a bucket of water or a garden hose nearby when using your BBQ.
- Never use your brick BBQ under a pergola or close to combustible materials.
- Check WorkSafe NZ guidelines for safe outdoor fire practices.
- If your region has seasonal fire restrictions, check with your local council or Fire and Emergency NZ before lighting up.
When to Call a Professional
If you're not confident with bricklaying, it's well worth hiring a qualified bricklayer to ensure your BBQ is structurally sound and built to last. A professional can also advise on the best materials for your local NZ climate — coastal areas, for example, need more corrosion-resistant materials. If you want a built-in gas burner, you must use a licensed gasfitter — this is restricted work under NZ law. Find qualified local bricklayers and tradespeople on tradedirectory.co.nz.
Licensed Building Practitioner (LBP)
