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How to Work with Concrete

If you’ve never worked with wet concrete before, it could be in your future. Many a comedy scene in a television show or movie has involved the soupy compound that magically turns hard in a matter of hours.

Concrete is truly a unique building material and is used for countless things around the average home. While it’s a very basic material having only four typical ingredienets - stone, sand, water and Portland cement - it’s a very complex material that will deliver less-than-desired results if you don’t know what to do.

Go watch this video of me mixing and starting to place concrete:

http://go.askthebuilder.com/concrete

Degree of Difficulty: hammer-2-5

Step One: Gather a wheelbarrow, a plastic bucket, a few shovels, one of them a round point one. A pair of work gloves and safety glasses is also a good idea.

Step Two: Purchase a couple of bags of bagged concrete mix from a hardware store or home center. You may be able to get it in different strengths. Always use the higher-strength concrete if you live in an area that gets freezing weather or the concrete needs to be really strong.

Step Three: When mixing concrete in a wheelbarrow, don’t try to mix more than one bag of premixed concrete at a time. It’s very hard to move the concrete around in the wheelbarrow and the deeper it gets in the tub of the barrow, the less likely it is that you’ll do a superior job of mixing it.

Step Four: Read the label on the bag of concrete and only add as much water as it says to add. You don’t want the mixed concrete so wet that it pours out of the wheelbarrow like a thin vegetable soup. The mixed concrete should resemble a thick chili.

Step Five: If pouring concrete on the ground, be sure the ground is tamped and compact. Slightly dampen the ground with a garden hose before placing the concrete in the forms. This dampness helps keep water in the concrete mix where it’s needed.

Step Six: If pouring a concrete pad, sidewalk, patio or structural column, it’s a good idea to incorporate some reinforcing steel. Steel rods, wire mesh, etc. are all made to help make concrete strong. Be sure you get at least 2 inches of concrete around the steel.

Step Seven: Tap the wood forms you use to help settle the concrete and avoid voids in the concrete. Use a wood board to float across the concrete to help jiggle it and drive the stones below the surface. You want to have the top one-eighth inch of the concrete be just the sandy mix element of the concrete.

Step Eight: The concrete will start to get hard depending on what the outside temperature is. In hot weather it gets harder faster. Once the surface depresses about one-quarter inch with normal finger or thumb pressure, it’s time to start to put a finish on the concrete with a magnesium or wood float. Rub the concrete lightly in circles with these tools to a desired finish or drag a broom across it for a unique look. Cover the finished concrete with heavy plastic for four days to allow it to cure properly.

Summary: If you’ve never worked with concrete before, PRACTICE one or two times before doing a real project that matters. Just set up temporary forms on your garage floor over a piece of heavy plastic. Mix up some concrete, place and finish it. Note how it changes over a period of several hours from a plastic slurry to a wet rock. You’ll be amazed!

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