Why Do You Need Gravel Under Concrete?

Gravel is a great way to add texture, interest and even value to your concrete driveway. But how do you know if gravel is right for your project?

Here are 7 reasons why gravel under concrete is not just a viable option but also the best one:

The Gravel Provides a Level Surface

Gravel is used to provide a level surface and protect the slab from erosion. This can be accomplished by placing the gravel at least one inch below ground level, so that it extends a few inches above your concrete slab when finished.

The gravel also helps hold in place during pour by keeping water from seeping into your foundation. The additional weight of the aggregate will help keep it in place as well as prevent debris from falling off while pouring, which could cause problems down the line if left untreated.

Gravel Acts as a Rebar Cage

gravel Foundation under concrete

Gravel acts as a rebar cage, which provides reinforcement to the concrete. This helps it hold up under weight and prevent cracking or sinking. If you have heavy objects on top of your patio or walkway, gravel could be used in place of sand for added support.

Gravel Strengthens the Concrete Mix

Gravel strengthens the concrete mix. If you’re using gravel, it will act as a rebar cage in your pour and provide strength to the finished product. Gravel also helps with drainage and erosion protection, which is especially important when pouring on an uneven surface like gravel.

The best way to ensure that your concrete has enough strength is by adding extra material—that’s why you should use crushed stone or sand if possible!

When filling cavities with gravel, make sure there are no weak points where water could get through; otherwise, those areas could cause cracks in your foundation later down the line

concrete gravel rebar

Drainage and Erosion Protection

concrete drainage

Gravel can also help prevent water from pooling and seeping through the concrete slabs and driveways. If you have a lot of rain, some of that water will enter your foundation—and if it pools, it could cause erosion problems. Gravel prevents this from happening by allowing rainwater to drain away from the foundation as it pours down into gutters or drains that lead into nearby rivers or streams.

That’s why gravel is so important for drainage protection: You want all that excess water to flow away from your house before it causes any damage!

Gravel Helps Hold the Slab in Place During Pour

Gravel is a great way to help hold the slab in place during the concrete pour. Gravel provides a level surface for concrete to spread out on, which prevents it from flowing into the wrong place. It also helps prevent cracking or sinking of your concrete floor as well as keeping it from getting too close to walls or fixtures that may be installed later on.

Gravel Exposes Weak Points in the Pour

Gravel is a fast and inexpensive way to find weak points in the concrete. It can be used before the pour, during the pour and after the pour.

  • Use gravel to check for cracks or holes while you are pouring. If you notice these areas of weakness before they’re filled with concrete, then you can fill them in with sand or other material while they are still wet so that they don’t get damaged by later steps of your project (like tamping).
  • Use gravel when tamping down an area where there might be a weak spot that needs filling—such as under stairs—to make sure everything is good enough for final inspection before any finishing work begins!
concrete pour

The Gravel Provides a Level Surface and Helps Drainage.

Gravel is used to level the slab and help with drainage. The water that runs off the surface of a concrete slab will cause erosion, which can damage your home’s foundation over time. Gravel also keeps your driveway in place while it hardens, which prevents any movement during pour and helps prevent cracks in your concrete driveway or walkway.


So, let’s recap. Gravel is a great way to make your concrete driveway or walkway more durable, as well as adding aesthetic appeal. It also helps support the slab during pouring, which can be important in areas where there might be settling issues caused by frost damage or other factors. If you’re looking for something new and different (and maybe even eco-friendly) then gravel is definitely worth considering! Please feel free to call Dallas Retaining Wall Contractors a call for a free estimate for your next concrete project.