How to Construct a Concrete Slab

Leveling the Ground for a Concrete Slab

Concrete slabs are used for a variety of projects depending on their size. You can build a small slab to hold an air-conditioning compressor or a large one for a patio. While concrete is not difficult to work with, careful planning through the steps and having plenty of help will make the project go more smoothly. If properly constructed, a concrete slab can bring you years of productivity and enjoyment.

Things You'll Need

• Shovel
• Wheel-barrel
• Measuring tape
• 2-inch x 4-inch x 8-foot wood board (number needed depends on the size of the slab)
• Wood saw
• 1 foot wooden stakes
• Hammer
• 3 inch nails, 1 box
• Ground compactor
• Masons level
• Steel wire mesh, 1 roll
• Water hose
• 2-inch x 4-inch x 12-foot wood board
• Masons float

Instructions

1. Measure off and stake the four corners where the slab will be poured. Dig out the area where the slab will be poured to a depth of 4 inches, using the shovel and wheel-barrel to remove the dirt.

2. Measure and cut the 2 x 4 boards to the lengths needed to make the over shape of the slab. Lay out the form boards and hammer a stake into the ground and each end of the form boards, and then nail the boards to the stakes. When complete you will have the form boards shaped to the outline of the slab and provide the support for the concrete as it cures.

3. Check the depth of the surface of the ground, using the measuring tape, to make sure it is consistently four inches deep. Use the shovel to remove any high spots or fill in any low spots. Use the level to make sure the ground is level so the slab sits square on the surface.

4. Compact the ground using the compactor to make the surface as hard as possible to better support the concrete as it settles over time.

5. Roll out the steel mesh wire inside the form boards and cut it to fit, until the entire surface has a layer of the mesh wire. The mesh wire will help strengthen the concrete.

6. Wet the surface with the water-hose. This will help keep the ground from absorbing the moisture out of the concrete before it has the time needed to properly cure.

7. Slowly pour the concrete into the form, starting at one end and working your way to the opposite end. Lay the 12-foot board from one side of the form over to the other and slide it back and forth from the end where you started pouring the concrete to the other. This will smooth the concrete out as the board acts as a bulldozer blade to push the concrete along.

8. Smooth off the surface of the concrete using the masons float. Start by stretching the float to the opposite side and slowly dragging it back towards you. This will help the small pebbles in the concrete to settle below the surface and give it a smooth surface.

9. Allow the slab several days to cure and complete harden all the way through the concrete.

Tips & Warnings

• Having a few assistants will help the project go more smoothly.

• Remember that the surface of the concrete will dry before the inside, so avoid walking on the slab or putting any significant weight on the slab as this could cause it to break or crack.

References

• Monster Guide: How to Pour a Concrete Slab

Resources

• Build Eazy: How to Make a Concrete Slab