Whether you are anchoring a post or adding an apron to your driveway, mixing concrete takes a certain degree of finesse. It is a fairly simple task but it can’t be rushed and does require a certain amount of forethought and attention to detail.
Doing it yourself can be much more cost effective than having concrete delivered. The national average to have it delivered is around $3,500. Mixing and pouring your own concrete is a fraction of that cost.
What You Need to Know
Important Note: Always wear your gloves, goggles, a disposable dust mask, and protective clothing before you open the first bag and do not take them off until you are finished.
Stones give the concrete its strength. The rocks need to be the right size for the concrete to maintain the proper strength, consistency, and aesthetics, although it is good to vary stone size.
The biggest stone in the concrete mixture should be no more than one-third of the thickness of the concrete you are pouring. So, a 4-inch-thick sidewalk should not have any stone that is larger than 1.333 inches in diameter.
Cement holds everything together once it has cured. It acts as a binder, holding the stone and sand in place.
Water is crucial to the mix. This is a balancing act. Too much water will dilute the cement paste. It won’t properly coat the gravel and sand, so it won’t stick. Too little water and it won’t place properly or finish like it should.
What You’ll Need
- Waterproof gloves
- Splash-proof protective goggles
- Concrete mix
- Mud pan, mixing trough, or wheelbarrow (depending on how much you are mixing)
- Mortar hoe
- Bucket containing water
- 1-quart container
If you’re planning a large project, you can pick up a concrete mixer for a few hundred dollars from popular home improvement stores. This optional tool can make stirring heavy mixtures or large batches faster and easier.
How to Properly Use Concrete Mix
Using a concrete mix is simple. Follow these steps:
- Lay the unopened bag of concrete in the wheelbarrow or trough.
- Cut the bag along its width. Gradually lift both ends to empty the contents into the trough. Make sure that you remain upwind so that the concrete dust does not blow back on you.
- Make an indentation or hollow in the center of the mix and add about two-thirds of the water per the instructions on the bag. Do not stir.
- Use your hoe to gently move the mix through the water, pulling and pushing until the water is completely absorbed.
- Add the remaining water a little at a time using the same pulling and pushing motion to mix. When the concrete is an even consistency, it is ready to use.
If while mixing, you find any dry pockets, don’t add more water. Instead, continue the pulling and pushing to incorporate the dry mix into the moistened mix.
Get the Proper Proportions
Concrete purists will eschew the ready-made concrete mix and opt for creating their own mixture instead. It is strictly up to the individual. When creating your own mix, know that the ingredients are what makes professional quality concrete. The proportions are precise:
- 2 parts sand (washed, clean, medium or coarse)
- 3 parts stone
- 1 part Portland cement
- Water (just enough to mix it correctly)
Mix the dry ingredients together first. Then, add just a little water at a time to achieve the perfect combination.
What’s the Right Consistency?
You have to find that perfect balance between concrete that is wet enough to mix but not so wet that it doesn’t stick together. The professional term for this is slump.
Test your mixture in your wheel barrow or container. If it stays on the sides and doesn’t fall, you have a good batch. It’s ready to be poured or installed.
By contrast, if you can’t get a slump or your concrete mix has the consistency of thick gravy, then you have far too much water. Try balancing the excess water with the other ingredients to thicken it to a good slump.
Another way to test slump: pick up some of the mixed concrete (make sure you are wearing your gloves) and squeeze it. It should hold its shape and not pool or drip.