If you want to work with concrete, you can begin with a small project like a concrete slab no bigger than 10’ x 10’.
- Portland Cement, sand and gravel or Concrete Mix
- 2x4s and Other Material for Formwork
- Reinforcing Mesh/rebar
- Long 2x4s for Screed
- Tape measure
- Carpenter’s square
- Spade or Shovel
- Garden hose
For your safety, avoid prolonged contact with fresh concrete which can burn your skin. Wear safety goggles, gloves, and protective clothing such as long sleeved shirts, denim pants and rubber boots.
Steps in Pouring a Concrete Slab
- You need to estimate the volume of concrete based on the size of your slab. For example, if you will make a 10’ x 10’ slab, you have 100 square feet. You have to compute the volume of concrete you need. You can look at the internet for concrete calculators and conversion tables.
- After deciding your square footage you should build the formwork, a wooden frame that borders the concrete and prevents it from spreading. The formwork should be laid on level ground and fixed with stakes.
- Then dig a trench around the perimeter of the project. A string stretched across the formwork can be used to show the depth of the trench. The trench should be at least 4 inches deep.
- Before pouring the concrete, lightly hose the trench area with water. Now you are ready to pour the concrete. Start pouring the concrete to a depth of three inches below the top of the formwork. Then place your rod of reinforcing steel on top of the concrete. The reinforcing steel will help to prevent cracking and hold the concrete slab together.Now you can pour the concrete up to the level of the top of the formwork. When you are finished, tap around the outside of the formwork with a hammer. The vibration will help the wet concrete to settle, and remove air pockets within it.
- A straight piece of lumber from your formwork can be used to screed or level out the concrete. Continue moving the screed with a sawing motion along the top of the formwork until all the concrete is level.
- For finishing, you can use a trowel to smooth over the level concrete. An ordinary broom can be used to create a pattern over the concrete. It provides a rough finish that makes the concrete surface less slippery when wet.
- You can take off the formwork the next day. Do not force it, however. Remove it only when it comes off easily.
- The concrete will cure in a few days. During this time, the surface should be kept wet by spraying it with a fine mist.