What You Need To Know To Identify Different Types of Fill Dirt

“Fill dirt wanted.”

What exactly is fill dirt? Essentially, it is subsoil that was removed during a construction project in order to create a smooth, stable surface on which to build.

If you’re in need of a lot of dirt, look into dirt exchange programs. Often, you can find free fill dirt or pay a much lower price. But not all dirt and soil is created equal, and you want to make sure that the fill dirt you buy will actually work in the way you need it to. That means determining what type of dirt you’re getting. How can you do this? There’s a simple test. You’ll need:

 A clear glass jar

 Water

 Dish soap

 A teaspoon

Fill the jar about two-thirds of the way with water. Add a teaspoon of dish soap to that water.

Then scoop fill dirt into the jar until the water level is about an inch from the top.

Close the lid, and shake vigorously for around 30 seconds. Then place the jar on a flat surface, so it can settle. Immediately, you will notice that all the sand in the sample settles on the bottom. It should be a pretty distinct layer. After about two minutes, the silt will settle out. True subsoil should contain little to no silt. Clay particles won’t completely settle out for at least a day, and may take up to a week.

Types of Fill Dirt

Once everything has completely settled out and the water becomes clear again, you can determine the type of fill dirt by looking at the proportions of different soil particles.

Clay-based fill dirt.

The top layer in the jar will be clay. If over half of the fill dirt consists of clay, you probably shouldn’t use it to fill planting areas unless you plan to put a lot of well-drained topsoil over it. However, fill dirt with this consistency can be used as a base for things like gazebos, sheds, and even pathways. To use it as topsoil, you want the percentage of clay to be closer to 10-20 percent.

Sand-based fill dirt.

Sand, as mentioned above, will make up the bottom layer in the jar. There are many uses for sandy fill dirt (which is at least 50 percent sand). It can help to level out your yard. You can use it to improve drainage by raising the grade of lower areas. It can even be used to fill areas meant for plants as long as you add 6-12 inches of topsoil to ensure your plants get the nutrients they need.

Screened fill dirt.

This type of fill dirt doesn’t have anything to do with the actual dirt itself. When fill dirt has been screened, it means rocks, roots, and other undesirable elements have been removed from it. You will pay more for fill dirt that has been screened, but it’s usually worth it. Unscreened fill dirt can sometimes have a high percentage of unwanted materials, including construction trash. In other words, you may end up paying for a lot of material you don’t want. Moreover, when dirt is screened it tends to have a consistency that’s more uniform, because big clods of clay get broken up, making it easier to use.