How To: Mix Concrete
Even if your only experience with the stuff has been to walk upon it, you can mix concrete successfully on your first attempt by following these simple, fool-proof steps.
Everyone knows how concrete looks and that it lasts for years and years. What you may not have realized is that preparing a batch of the stuff is basically a “just add water” affair. Even if you’ve never done it before, you can mix concrete in under an hour. Of course, there’s more to working with concrete than simply mixing the material. But being able to do successfully is the first step towards building something to stand the test of time. Once you’re familiar with the technique, a bevy of DIY projects in and around the home fall squarely within your range of capabilities. These include creating a walkway, a durable countertop, or a stylish weather-resistant planter. To be on your way toward such rewarding home improvements, follow the simple steps to learn how to mix concrete like a pro.
Concrete mix usually comes in a paper bag, on the front of which you’ll find the yield of the package listed in cubic feet. Know that for smaller DIY projects, you are going to need the entire bag. For larger projects (e.g., patios), you’ll need all that and then some. Several full bags are likely to be in order, though depending on the task at hand, you may choose not to mix all the concrete needed at one time. If you’re confused about how much concrete to buy, use a quantity calculator like this one from Quikrete. Whether you need the entire bag or only a portion of it, place the package into your wheelbarrow, cut it open, and by lifting the bag gently upwards, empty out as much of its contents as called for by the job. On a windy day, do this step indoors, perhaps in the garage, to avoid making a mess.
Having filled up your watering can in preparation for the project, pour a little of the liquid into the center of the mounded concrete mix. Continue pouring in water little by little until you’ve added the amount specified in the manufacturer’s instructions. Be careful not to put in too much water; you can always add more, but you can’t take any out. And remember that if you only need a portion of the concrete mix—half, for instance, or a quarter—then you must adjust the “recipe” accordingly. Worried about using too much or too little? Allay your uncertainty by employing a kitchen measuring cup to fill the watering can with a carefully pre-measured volume of water.
Combine the concrete and water, working the material in a back-and-forth motion, using either a shovel or garden hoe. The goal here is to evenly distribute the water across the powder. If you’ve used water conservatively, you may find that as the mixture stiffens, it appears dry and crumbly. In that case, add more water until you’ve achieved a relatively smooth, moldable consistency, with no standing puddles.
Test your concrete with the “slump” test. Here’s an easy way to do it. First, cut the bottom off a plastic or paper cup. Next, shape the container into a cone. Scoop up enough concrete to fill the cone, then empty the cone onto a flat surface. If the concrete collapses to about half the height of the cone, perfect—you’re ready to go. If the concrete loses none of its height—that is, if it doesn’t slump at all—go back and add some more water. If the concrete collapses considerably farther than half the height of the cone, you’ve added too much water and must compensate with additional mix (or in a pinch, dry sand can be used).
Your wheelbarrow should now be filled with usable concrete. Move it to wherever you’re going to be working. Meanwhile, leave any tools that have touched concrete (e.g., your shovel) in a bucket of water. That way, the concrete won’t set on the tool, and you’ll have the opportunity to clean it properly later on. To keep your wheelbarrow spic and span, aim to empty empty and clean it as soon as possible. Once the concrete sets, it’s going to be mighty difficult, if not impossible, to remove. Of course, strength and durability are selling points for concrete, but now that you’re working with the stuff, you are likely to find that you see concrete and its characteristics from a fresh perspective.