Anyone taking on a construction or home improvement project will eventually face the dilemma of choosing between concrete and cement at the hardware store. Should I buy concrete or cement?

You should buy concrete, not cement, for most construction projects. Concrete is the complete ready-to-use mixture that includes cement, while cement is just one ingredient that needs to be mixed with sand, gravel, and water to create concrete.

Keep reading to understand the key differences between concrete and cement, as using the wrong material could lead to project failure and wasted money. Plus, you’ll learn which specific situations might actually call for cement instead of concrete.

What’s The Difference Between Concrete And Cement?

Cement is actually just one component of concrete, making up about 10-15% of the total mixture. Think of cement as the “glue” that holds concrete together. When mixed with water, cement creates a paste that binds with other materials like sand and gravel (known as aggregates) to form concrete.

Concrete is the final product that results from mixing cement, water, sand, and gravel in specific proportions. This combination creates a strong, durable material that can withstand heavy loads and weather exposure. The aggregates provide bulk and strength, while the cement paste fills gaps and creates bonds between the materials.

When Should I Use Cement Instead Of Concrete?

Pure cement is typically only needed for specialized projects like making repairs to existing concrete, creating a bonding surface between old and new concrete, or mixing custom concrete batches. For these applications, you might buy Portland cement, which is the most common type.

If you’re doing minor repair work, like filling small cracks or creating a thin layer of mortar for tiles, cement might be the right choice. However, even in these cases, you’ll usually need to mix the cement with sand to create mortar.

What Type Of Concrete Should I Buy For My Project?

For larger projects, traditional concrete gives you more working time. Many concrete supply companies offer different formulations designed for specific applications, so don’t hesitate to ask for recommendations. For walkways and patios, choose concrete rated at 2,500-3,000 PSI. For driveways and foundations, use 3,000-4,000 PSI concrete.

Fast-setting concrete is available for small projects like setting posts or poles. For larger projects, traditional concrete gives you more working time. If you’re unsure about the amount needed, remember that one 80-pound bag of concrete mix typically yields about 0.6 cubic feet of concrete when mixed with water.

How Do I Know How Much Concrete To Buy?

To calculate how much concrete you need, multiply the length, width, and depth (all in feet) of your project area to determine cubic feet. Then multiply by 1.1 to account for waste and uneven ground. For example, a 10′ x 10′ patio that’s 4″ (0.33 feet) deep would need 33 cubic feet of concrete.

Most concrete is sold in 80-pound bags that yield 0.6 cubic feet when mixed. For the patio example above, you’d need about 55 bags. For larger projects, consider ordering ready-mix concrete by the cubic yard (27 cubic feet per yard) from a local supplier.

What If I Make A Mistake Choosing Between Concrete And Cement?

Using cement alone where concrete is needed will result in a weak structure that’s likely to crack and crumble. Cement without aggregates creates a product that’s too brittle for construction purposes and won’t hold up to weather or weight.

Using concrete where only cement is needed, like in small repair jobs or thin mortaring applications, can make the job more difficult and expensive than necessary. The aggregate in concrete can make it too coarse for detail work and prevent proper adhesion in repair situations.

The good news is that both materials are relatively inexpensive, so making a mistake won’t break the bank. However, the real cost comes from the time and effort needed to remove and replace incorrectly used materials, plus any potential damage to the underlying structure that needs to be fixed.

Time To Get Building

Before heading to the hardware store, take 5 minutes to measure your project area and calculate the exact amount of concrete you’ll need using the length x width x depth formula. This simple step will ensure you buy the right amount of material and choose the appropriate PSI rating for your specific project. Plus, having these measurements handy will make it easier to get accurate advice from store staff if you need help selecting the best concrete mix.