12 Most Common Mistakes When Pouring Concrete

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Troweling Too Soon/Too Late

Smoothing concrete with a trowel to give it a nice surface before it hardens is called finishing, and this step has to happen at just the right time.

Ideally, you want to finish concrete when the surface water has dried, but the concrete is still soft and workable. Trowel concrete too early and you’ll get even more surface water forming, leading to a concrete surface that will flake and fail in time. Trowel too late and you won’t be able to create a smooth surface because it’s no longer soft enough. The time to wait before finishing varies depending on air temperature and how wet the concrete is to begin with.

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Concrete-to-Skin Contact

The cement in concrete is highly alkaline, and that means it can injure your skin. The tricky thing is, you can get wet concrete on your hands all day long and notice nothing until the end of the day. That’s when red, painful areas of thin, dissolved or cracked skin shows up. Use a trowel and shovel to handle wet concrete. And to be safe, wear gloves.

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Weak Concrete Mix

The most economical way to obtain concrete is to mix your own from Portland cement, sand and crushed stone. This is considerably less expensive than buying just-add-water concrete mix in bags.

But beware — if you mix your own, don’t cheat yourself. The standard concrete recipe is one part cement, two parts sand and three parts clean crushed stone. Don’t skimp. Crushed stone is filler, so don’t use any more than the recipe calls for. In fact, use a little less stone proportionally if you have a hard time troweling a nice, smooth surface.