If you’re about to have new concrete poured, it’s important to carefully prepare the ground beforehand. A smooth, compact surface under the new concrete will help to prevent cracking of the new pavement due to unstable soil underneath. Follow these steps to prepare the ground surface before your new concrete is poured.
- Make sure the ground surface is the proper depth, and dig it out if it’s not. Generally speaking, concrete will sit about 1 to 2 inches higher than the dirt around it, and 2 to 3 inches of the concrete will sit below the surface of the ground, so the depth of the ground should be anywhere from 3 to 5 inches deep.
- Using a rake or a hoe, smooth out the dirt surface. Dig out any high spots and fill in low areas. Make the ground as even as possible.
- Using a hand tamper or a mechanical tamper, tamp the ground to pack down the soil. A mechanical tamper is much less work than doing it by hand. You should be able to rent one at a home improvement center or rental store. The finished, tamped soil should be completely smooth and firm.
- Spread a 2-inch layer of tiny rounded gravel on top of the tamped soil. This will provide for adequate drainage underneath the surface of the concrete. Tamp the gravel until that surface is as smooth as possible.
- Finally, spread a very thin layer of cement sand on top of the gravel. Slightly dampen the sand with water, then let it dry for at least one hour before pouring the concrete.
Making adequate preparations before your concrete is poured may take a little time, but it’s one of the most important steps in making sure that your new concrete pavement is stable and remains free of cracks for as long as possible.
Photo credit: Jessica Merz