How Much Does A Concrete Slab Cost? The Complete 2026 Guide

Average Concrete Slab Cost

For most homeowners across Australia, the average concrete slab cost falls between $75 and $160 per square metre, depending on slab type, thickness, reinforcement, finish, and site preparation. Smaller jobs typically attract minimum call-out fees, while larger jobs benefit from economies of scale.

A typical 30 sqm shed base costs $2,250 to $3,300 for a plain reinforced finish.

Cost Per Square Metre Explained

Most concreters in Australia quote in square metres. For a standard 100mm reinforced slab with steel mesh, the price starts at around $75 per m² and increases based on your chosen finish and any extra preparation needed. For heavier-duty applications — such as machinery sheds or commercial floors — pricing rises due to thicker concrete, stronger reinforcement, and higher-strength mixes.

Always confirm whether the quote is per square metre or a fixed lump sum. Lump sum quotes can obscure scope creep; a per-square-metre quote makes it easy to compare contractors and understand exactly what you're paying for.

What Affects Concrete Slab Pricing?

1. Slab Size

Larger slabs cost more overall but less per square metre. A 100 sqm shed floor will always come in cheaper per m² than a 10 sqm garden shed base, which may hit the contractor's minimum job fee.

2. Slab Thickness

Standard residential slabs are 100mm. Garages and workshops often spec 125–150mm. Commercial or heavy machinery slabs can reach 200mm or more. Thicker slabs require more concrete volume and stronger reinforcement.

3. Reinforcement

Steel mesh is standard for most residential slabs. Heavy-duty rebar is required for thicker or load-bearing applications. In reactive clay soils — common across Brisbane — additional reinforcement or a stiffened raft design may be required by a structural engineer.

4. Site Access

Easy front-yard access keeps prices down. Backyards, steep terrain, or narrow gate access may require concrete pumping or manual wheeling, both of which add cost.

5. Site Preparation

Excavation, levelling, removing tree roots, and importing fill are all additional costs. A site that's already level and free of obstacles is the cheapest starting point. Always ask your contractor what site prep is included in the quote.

6. Finish Type

Plain broom finishes are the cheapest. Exposed aggregate, stencilled, stamped, and polished concrete finishes require additional materials, time, and skill — all of which add to the price.

7. Concrete Strength (MPa)

25 MPa is standard for most residential slabs. 32–40 MPa is used for heavy-duty applications and costs more per cubic metre of ready-mix. Your concreter will recommend the right strength for your use case.

8. Location and Travel

Rural and regional properties may attract additional ready-mix delivery fees. Within the greater Brisbane area, pricing is generally consistent across suburbs.

9. Drainage and Falls

Proper drainage design adds slight cost upfront but extends slab lifespan significantly. A slab that pools water will deteriorate faster and create safety hazards. Always confirm falls are designed into the slab.

Concrete Slab For Shed Cost

Shed slabs are one of the most common concreting jobs across Brisbane. Use this as a budget guide:

The cost depends on slab thickness, reinforcement, and site preparation. Heavy-duty workshop or machinery slabs require thicker concrete and additional rebar. Ensure your concreter discusses falls, edge thickening, and bolt-down points. Ask about a thickened edge beam for better structural performance.

House Slab Cost

A house slab is one of the largest and most critical concreting jobs. Common slab types and their price ranges:

• Waffle pod slabs: around $90–$130 per square metre
• Raft slabs: around $100–$140 per square metre
• Stiffened raft slabs (reactive clay soils): around $120–$160 per square metre
• Piered slabs (problem soils): $150+ per square metre

For a 200 sqm home, the total slab investment typically ranges from $18,000 to $32,000, including engineering, formwork, reinforcement, plumbing rough-in, concrete, finishing, and curing. Soil tests are essential — reactive clay soils common across Brisbane often require stiffened slabs or piering.

What a Quote Should Include

A professional quote should be detailed and itemised. Here's what to look for:

• Site inspection and assessment
• Excavation and site preparation
• Removal of existing concrete if required
• Formwork supply and installation
• Steel mesh or rebar reinforcement
• Concrete supply and pumping (if needed)
• Pouring, screeding, and finishing
• Curing and sealing (if applicable)
• Site cleanup and waste removal
• Written workmanship warranty

Always request a written breakdown — this prevents misunderstandings and lets you compare quotes accurately across multiple contractors.

Brisbane Slab Pricing

In Brisbane, concrete slab pricing is broadly in line with national averages. Some local factors worth knowing:

• Reactive clay soils across Brisbane (Mount Gravatt, Holland Park, western suburbs) often require stiffened slabs or extra reinforcement
• Sloped blocks in Bridgeman Downs, Eatons Hill, and Albany Creek may need stepped slabs or additional fill
• Tight access in older inner suburbs may require pumped concrete, increasing costs
• Wet seasons can delay pours, so plan ahead during summer months

A 25 sqm shed base in Brisbane typically costs $1,800–$2,800. A 60 sqm patio slab usually ranges from $5,000 to $8,500 depending on finish.

Old Slab Removal Cost

Sometimes a new slab project starts with removing an old one. Concrete removal typically costs $40–$90 per square metre, including disposal at a licensed recycling facility. Smaller jobs attract a minimum fee of $400–$800. Reinforced slabs cost more to remove due to the additional time required to cut and separate steel mesh.

When bundling removal with a new pour, many contractors offer better combined pricing than booking them separately. Always ask whether removal and the new slab can be quoted together.

Cost-Saving Tips

1. Get multiple quotes — at least three written quotes ensures fair pricing and lets you spot anything missing from individual tenders
2. Book during quieter periods — winter and shoulder seasons often offer better contractor availability
3. Combine jobs — pouring a shed slab and pathway together is cheaper than booking two separate projects
4. Prepare your own site if possible — clearing vegetation yourself may reduce labour costs before the concreter arrives
5. Choose the right finish — plain broom finishes are dramatically cheaper than decorative options and still deliver decades of reliable performance

How to Choose a Contractor

Look for contractors who can demonstrate:

• Current QBCC licence (required for jobs over $3,300 in Queensland)
• Public liability insurance
• Written workmanship warranty (6–12 months as standard)
• A strong portfolio of local, comparable projects
• 4.5+ star Google reviews with consistent local feedback
• Clear, itemised written quotes with transparent pricing

Whether you're laying a small garden shed base, a large house slab, a workshop floor, or a backyard patio, the right preparation and the right team make all the difference. By comparing detailed quotes, verifying credentials, and asking the right questions, you'll get a high-quality slab that delivers decades of reliable performance.