Bags vs Ready-Mix Concrete: Which Should You Choose in Australia?
One of the first decisions for any concreting project is whether to mix your own concrete from bags or have ready-mix delivered by truck. Both options have their place, and the right choice depends on your project size, timeline, budget, and physical capabilities.
The Breakeven Point
As a general rule, bagged concrete is usually the cheaper option for projects under 0.3 cubic metres. For volumes over 0.8 cubic metres, ready-mix almost always wins on cost and practicality. The zone between 0.3 and 0.8 cubic metres is where the decision becomes less clear-cut and depends on your specific circumstances, including access for a concrete truck, how quickly you need to complete the pour, and how much physical labour you want to do.
Advantages of Bagged Concrete
Bagged concrete offers flexibility that ready-mix cannot match. You can buy bags from Bunnings or any hardware store without booking in advance, and you work at your own pace. There is no minimum order quantity, so you only buy what you need. For sites where a concrete truck cannot access, bags are often the only option. You can also do the work over multiple sessions if needed, which is not possible with ready-mix that must be placed within a limited time window.
Advantages of Ready-Mix
Ready-mix concrete arrives fully mixed to precise specifications, ensuring consistent quality throughout your pour. The time savings are enormous. Placing 1 cubic metre of ready-mix takes perhaps 30 minutes to an hour, while mixing the equivalent 108 bags by hand could take an entire weekend. There is no physical strain of lifting and mixing 20kg bags repeatedly. The concrete is also fresher and more workable than what you can achieve with bags, giving you a better finish.
Hidden Costs of Bagged Concrete
The per-bag price at the hardware store does not tell the full story. Unless you have a concrete mixer, you will need to hire one at $50 to $80 per day. Your time has value, and mixing bags is slow, hard work. Each bag weighs 20kg, and for a 1 cubic metre job, you will lift over 2 tonnes of material. There is also delivery to consider if you cannot fit enough bags in your vehicle, though most hardware stores offer delivery for a fee.
Hidden Costs of Ready-Mix
Ready-mix suppliers typically have minimum order quantities, often 0.5 cubic metres, and may charge small load fees of $50 to $100 for orders under 1 cubic metre. Weekend and after-hours deliveries usually attract surcharges. If the truck cannot get close to your pour location, you may need a concrete pump at $300 to $500 or more. Delays in placing the concrete can result in the load going off, leaving you with hardened concrete and a wasted delivery.
Current Australian Pricing
At the time of writing, 20kg bags of concrete mix retail for approximately $8.50 to $12.50 at major hardware stores like Bunnings, with prices varying by brand and location. Ready-mix concrete is typically priced at $280 to $420 per cubic metre delivered, depending on the concrete strength, your location, and the supplier. Metropolitan areas generally have more competitive pricing than regional areas. Always get quotes from multiple suppliers for larger jobs.