Anyone who has done concrete projects themselves before will tell you that the most difficult part is almost always the preparation. The actual pouring of the concrete is a fairly straightforward process if you have taken the time to properly prepare the project area. Unsurprisingly, we get the most questions pertaining to that preparation phase. Today, we’re going to address one of the most common: can you pour concrete over dirt?
A good base is everything when it comes to successful concrete projects. If the base you are pouring the concrete onto is flawed in any way, it is going to directly impact the quality of the final product. That’s why dirt isn’t always advisable. If the weight of the concrete deforms the dirt base in any way, the entire concrete structure will be flawed.
All of that is not to say that it is impossible to pour concrete over dirt. You can absolutely do it successfully, but you need to follow a specific process. Let’s take a closer look at the steps to that process.
There are two many things you need to worry about when building a solid base for concrete construction. The first is the thickness of the base, and the second is how compacted that base is.
Take some wood planks and create a frame around the area that is going to make up the base of your project. This will help keep all of the dirt and soil stacked in the correct area and stop it from spreading when you begin compacting it down.
The thickness needed for a base varies by the type of project you are working on. If you’re building something like a driveway, you’re going to want a 10-12 inch deep base. If you’re building a sidewalk, you can get away with 6-8 inches.
It’s also worth mentioning that the soil conditions and climate in which you are working will also have an effect on the way you need to pack the base. For instance, a colder climate will necessitate a thicker base. Be sure to do your research, and don’t hesitate to reach out to a professional concrete contractor for more information.
Super dry dirt does not compact as well as moist dirt. That’s why it’s important to spray down your base every few layers before you begin compacting. You don’t want to add so much water that you’re dealing with mud, but you want the entire surface of your base to be damp.
Once you have all the dirt and soil you need poured into your project area, you need to compact it. The best way to do this is to use a plate compactor. This lawn-mower-like tool uses a heavy metal plate to compact all that soil together to create a strong compact base that concrete won’t seep into. You’ll likely need to take four or five passes with the plate compactor to achieve the desired stability for a dirt base.
Long story short, yes you can pour concrete over dirt. However, you need to follow the process outlined in this article for the best results. If this all seems a bit overwhelming, we suggest reaching out to a professional concrete contractor. Razorback Concrete is always willing to work with you. Visit www.razorbackconcrete.com to learn more.