How to Mix and Pour Concrete

Concrete slabs can be used for many different purposes. They make excellent patios or walkways, or can be a good foundation for decks, a shed, greenhouse, garage, or even larger buildings on your property.

Pouring a concrete slab isn't as hard as one might think. Here are some easy, do-it-yourself steps to follow:

STEP ONE - Level and Set Up Forms

The first step is to level out the area, making sure it is free of debris. Next, set up your forms. This will ensure that the cement goes and stays where you want it to be, creating a boundary for your slab.

Measure out the area where you want your slab poured. Then stake 2 x 4's (upright) around the perimeter (be sure that your stakes are on the outside of your forms). The stakes will hold your forms in place while the heavy cement is being poured.

STEP TWO - Sand and Rebar

Before pouring your cement, you will need to add a layer of sand within the forms. Next, set in the rebar, approximately every 2 square feet, length and width. This will give your cement slab added strength and stability, especially if you will be adding weight to it, or building onto the slab.

STEP THREE - Pour, Place and Screed

Now you are ready to pour your cement. If you are mixing the cement yourself, a good mixture is 4 measures of sand to every 1 measure of cement. You can either use Portland cement or sulphur-resistant Portland (Sulphur-resistant cement is recommended if you will be parking a vehicle on your slab. This will ensure a longer life span to the cement slab). You can either mix your cement using a cement mixer, or by hand in a wheelbarrow, depending upon how much cement you will be needing, and the size of your slab.

If you are pouring a much larger slab, you will need to hire a cement contractor who will bring the cement to your home in a cement truck. After pouring off the cement, they will then leave you to finish the process yourself.

When mixing the cement yourself, be sure that the consistency is correct. If it is too thin and soft, it will take longer to dry. It will also be harder to work with if you need to incline your slab for the purpose of water run-off. If it is too thick, it will dry too quickly, compromising the curing process and subsequent strength of the slab. It may also have a greater tendency to shrink and crack if it is too thick.

Now you must place and screed the cement. In this procedure you are positioning and leveling out the wet cement within your formed area. This can be done using a 2 x 4, running it across the cement, using the forms as your leveling guide.

STEP FOUR - Float

Once your cement is leveled, you must now use a bull float to taper the area. This ensures that your slab will be level throughout, without lumps, bumps and unwanted curves in the finished slab.

STEP FIVE - Broom and Edge

Allow approximately an hour or two for the surface of the newly poured cement to dry. If your cement slab will be exposed to the elements, it's a good idea to broom the surface. Brooming (running a push broom lightly along the surface of the cement) creates a better, non-slip texture to the cement, especially if your slab will be used for either a patio, driveway or walkway.

If your slab is for the purpose of placing a shed, garage or building on it, the brooming step can be eliminated.

Lastly, you want a nice, clean edging to your slab. Using an edger (a tool specific to this purpose), lightly run it along the outer edge of your slab. Be sure to periodically wet the edger so that you are not "dragging" the wet cement out of place.

The 2 x 4 forms can be removed anytime after the first day or two.

STEP SIX - Curing Time and Maintenance

Depending upon the size of your slab, it is recommended that you allow 28 days for it to set up or cure. This is necessary if you will be parking, placing heavy objects, or building on it. If it will be used for the specific purpose of a patio or sidewalk, you will be able to walk on it within a matter of days.

Use this waiting time to periodically spray the cement lightly with a garden hose. This will help to cure it further, as well as prevent cracks from forming on your new slab.

If you follow these few easy steps, you should have no problem pouring a concrete slab yourself. You can soon make use of your new concrete slab, and enjoy the accomplishments of a job well done.