Mixing concrete is a basic skill that every DIYer should know how to do. Concrete is one of the most common and inexpensive building materials on the planet and is made up primarily of sand, gravel, and cement.

Mixing concrete is similar to baking in that to achieve consistent results, it’s best to follow a specific recipe. There are a multitude of different concrete mixes for different applications depending on the strength, workability, and application of the concrete.

Mixing concrete is very much a science for professionals, but for the average backyard enthusiast, learning the basics of concrete is enough to get you started.

When mixing concrete, you’ll need to mix aggregates such as sand and gravel along with powdered cement and water as a catalyst to begin the chemical bonding process of the ingredients. The concrete mix is ​​a function of proportions where you will measure the volume of aggregate used to the volume of cement used.

The most common concrete mix used around the world is the 3-2-1 mix which uses three parts gravel, two parts sand and one part cement. The water is added with the idea that you should use as little water as possible to make the concrete workable for what you need it for. The viscosity of concrete is measured by “slump”, which refers to a specific test in which the amount a concrete-filled cone will lose its shape once the cone is removed is measured in inches or mm. A concrete with zero slump would be too stiff and dry and tilted to hold its shape, while a concrete with a slump of six inches or more would be extremely wet and not tilted to hold its shape.

The 3-2-1 mix is ​​widely used because it can fill large areas with concrete for a relatively low price. You could potentially use just sand and cement, no gravel, to create what’s called mortar. In the 3-2-1 mix, the gravel serves as filler, taking up a large amount of space while maintaining a relatively high overall strength. The disadvantage of the 3-2-1 mix is ​​that the larger gravel aggregate will often float to the surface during finishing and is not suitable for fine or detailed concrete applications.

The best general mix for a DIY enthusiast to memorize and use is a simple 3:1 mortar mix. By using three parts sand and one part mortar, you can create the strongest concrete possible, as well as concrete that is easy to finish and detail with patterns, templates, or stamps. By not using the gravel, the mortar will have an overall smoother consistency, but will ultimately take up less volume than concrete made with gravel as well. If you are pouring large volumes of concrete, gravel could be profitable; however, for most DIY projects, a 3:1 mortar mix is ​​the way to go.

The sand you need to use for a 3:1 mortar mix should be sharp sand, masonry sand, or joint sand. Every place you buy sand will use a different term, so it can be confusing when shopping. All you need to remember is to avoid playing with sand. Play sand is sand that has been washed and sterilized (this is fine) and then rolled to smooth out all the edges of the individual sand grains (this is bad).

The sharp edges of the sand help hold the concrete mix together better than the rounded edges of poured sand. Ideally, you’d like to find sand at landscaping supply stores that will sell you by the cubic yard. With a strong trailer, you can collect all the sand you may need for next to nothing, plus the quality of sand for making cement will be very high.

The applications for a DIY enthusiast using a 3:1 mortar mix are vast. Everything from repairing broken exterior steps and stairs, driveways, patios, decks, ponds, waterfalls, artificial rock, statues and much more is possible with a simple mix of sand, cement and water.

Start with small concrete projects to get a better idea and understanding of how to work with concrete. Since concrete is so popular all over the world and is such an advanced science, you will never run out of interesting concrete applications to learn or try. Combined with being the most affordable building material on the planet and readily available everywhere, learning how to mix basic concrete recipes is a fundamental DIY project.