How to Build a Concrete Slab | Lowe's (2024)

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How to Build a Concrete Slab | Lowe's? ›

Concrete is the ideal material for walkways, patios, or foundation slabs. Pouring a slab yourself can easily save you half of the cost of hiring it out. All you need is a clear day, the right tools, and these seven steps.

Concrete is the ideal material for walkways, patios, or foundation slabs. Pouring a slab yourself can easily save you half of the cost of hiring it out. All you need is a clear day, the right tools, and these seven steps.

Working With Ready-Mix Concrete

And, if you mix it yourself, it's the cheapest way to make your slab. For most do-it-yourselfers, the best material for building a concrete slab is a ready-mix, crack-resistant concrete product. The wet mix is poured into a prepared wood form, then left to cure.

It is not advisable to pour concrete directly on dirt. Even compacted soil—known as a subgrade—is not strong enough to maintain the form of concrete. You can, however, pour concrete over concrete as long as the overlay has proper bonding agents and the slab below is clear of damage.

Concrete slabs or driveway pads do not require reinforcing for vehicles, light trucks, or lounge chairs. Rebar is recommended if the concrete must support heavy machinery, heavy-duty cars, a hot tub, a spa, or a concrete pizza oven.

Gravel provides a level surface for concrete to spread out on, which prevents it from flowing into the wrong place. It also helps prevent cracking or sinking of your concrete floor as well as keeping it from getting too close to walls or fixtures that may be installed later on.

The number of 80 lb bags of concrete required for a slab depends on its size. Each 80-pound bag yields approximately 0.022 cubic yards of concrete. For a 4-inch thick, 100-square-foot slab, you'll need 56 bags. It's essential to calculate the volume based on your slab's dimensions.

Using the previous example of a 10 x 10 slab with a volume of 3.70 cubic yards, the number of bags you would need based on each bag size are as follows: 40 lb bag: 3.70 * . 011 = 366 bags. 60 lb bag: 3.70 * .

“Fill dirt” will be free draining; meaning that it will not retain water, therefore cannot expand and contract below your concrete slab, causing foundation failure.

Do I need to compact soil before pouring concrete? ›

The soil should be compacted in layers. This requires special equipment called a jumping jack or sheep's foot and the soil should be free from debris such as sticks. To get the best impaction possible. The soil should be compacted in layers.

Dampening the Earth

Next, you need to dampen the soil. Loose, dry dirt won't make a good foundation for a slab or the base that goes under it. You can use a garden hose with a nozzle attached to get an even, light spray across the dirt.

Is it cheaper to pour concrete yourself? Yes. In general, you can save up to 40% or more if you pour a concrete slab yourself. If you decide to mix your own concrete, you can save even more.

Choosing ready mix concrete saves vast amounts of time. It won't necessarily save you money but it is convenient. You also need to think about consistency. It is harder to get the consistency of your concrete right if you have to mix each batch individually.

The concrete slab construction process includes the preparation of formwork, compaction of a slab bed, placement of reinforcement, pouring, compacting, finishing the concrete, removing formwork and curing the concrete slab.