Bagged Concrete vs Ready-Mix: When to Order a Truck

The bag math

A standard 80 lb bag of concrete mix yields about 0.60 cubic feet. A cubic yard is 27 cubic feet, so it takes 45 bags, or 3,600 lb of dry mix, to make one cubic yard. That figure frames the decision.

Work out your own job with the concrete calculator.

When bags make sense

• Post holes and footings for decks and fences, where each hole is a small pour.
• Small pads for an air conditioner, trash cans or a step.
• Repairs and odd jobs where you need a few bags spread over days.
• Places a truck can't reach, such as backyards without access, although a pump or buggies can sometimes solve that.

For bagged jobs, a concrete mixing tub and a sturdy hoe are enough for a few bags at a time; a rented drum mixer speeds up bigger batches. Bags let you work at your own pace, buy only what you need and return unopened bags if the store allows.

When ready-mix makes sense

• Larger slabs and patios. A slab should be placed and finished as one continuous pour, or in planned sections with joints. Mixing dozens of bags fast enough to keep a wet edge is hard work for a small crew.
• Consistency. A batch plant mixes every load the same way. Hand or small-mixer batches can vary in water content, which affects strength.
• Labor. Lifting and mixing thousands of pounds of bags takes time and people. Ready-mix arrives ready to place.

Comparing cost honestly

Prices vary widely by region and over time, so get current quotes rather than relying on any general figure. To compare fairly:

1. Bag cost: number of bags × price per bag, plus mixer rental if you need one.
2. Ready-mix cost: price per cubic yard × yards, plus delivery, any short-load or minimum charge, and pump or wait-time fees.
3. Add the value of your time and helpers on bag day.

Many suppliers have a minimum order or charge extra for small loads, so ask for a quote at your exact volume.

Before the pour

• Call 811 to have utilities marked before digging.
• Build and brace forms; check they are level or sloped as planned.
• Have enough help and tools ready: a wheelbarrow, shovels, a screed board, a float and an edger.
• Plan the weather. The bag data sheet gives temperature guidance for placing and curing concrete.

Safety

Wet concrete is caustic and can burn skin. The product data sheet calls for protective gear. Wear waterproof gloves, eye protection, long sleeves and long pants, and wash off any concrete that gets on your skin promptly. Bags are heavy; lift with your legs, or use smaller bags if 80 lb is too much to handle safely.

Mixing bags well

The bag's data sheet gives the water quantity per bag. Adding much more water than that makes the mix easier to place but weaker, so add water gradually until the mix reaches a workable consistency. Mix each batch thoroughly so no dry pockets remain, and place it promptly. For a slab, have one person mixing while others place and screed, so the pour keeps moving without long gaps between batches.

A simple rule of thumb

If you can mix and place every bag before the first concrete begins to stiffen, bags will work. If not, plan a ready-mix delivery or split the job into sections with planned joints.

Common questions

How many bags of concrete is too many to mix by hand?

There is no fixed number; it depends on your crew and mixer. As a reference, a 10 × 10 foot slab 4 inches thick needs about 62 bags of 80 lb mix with a margin, which is nearly 5,000 lb to lift and mix.

Can I pour a slab in sections with bags?

You can, using planned joints between sections. What you want to avoid is an unplanned stop where fresh concrete is placed against concrete that has already begun to set.

What should I ask a ready-mix supplier?

Minimum order, short-load fees, delivery charges, how long the driver can wait, whether the truck can reach your forms, the mix strength they recommend for your job, and how far ahead to book.

Is there an option between bags and a full truck?

Some suppliers offer trailer loads or small-batch mixing trucks. Availability varies by area, so ask locally.