What Is Drain Rock & How Is It Used?

What Exactly Is Drain Rock?

Drain rock is the term used for any type of rock that is designed to help manage your landscape area deal with moisture. There are many practical applications for drain rock, and we’ll go into a little bit more detail on those in this blog post. Using rocks as part of a drainage system has been used in architecture for thousands of years. The one thing that all drain rock has in common is that they have a general porous texture which allows for the free movement and absorption of water.

When deciding on the type of drain rock to use, it is helpful to know that you have options regarding the size of the rock. You can use fairly large rocks, up to about 1 ½” diameter, all the way down to pea gravel. Different sizes tend to work a little better for different applications, which we’ll get into now.

How Can You Use Drain Rock?

While the purpose of drain rock is mostly functional, that doesn’t mean they can’t necessarily look quite nice as well. Different functions call for different types of drain rock. Drain rock comes in a variety of sizes and colors, so the possibilities are endless! There are dozens of potential uses for drain rock, but we’re just going to have a quick look at some of the most common applications.

French Drains

You may never have seen a French drain before, but you most assuredly have walked over one and not even known it. A French drain consists of a perforated pipe that is buried underground, and is designed to carry water away from the foundation of structures. Drain rock is laid over these pipes in a trench or hole, which allows water to flow through them and into the perforated pipe. This is a wonderfully efficient way to protect structures from water damage at the foundation line. Typically, larger drain rock is used for French drains, like 1 ½” or ¾” rock.


While you could use drain rock to construct an entire driveway, you will typically use a smaller gravel for that. However, it is often very useful to use drain rock along the edges or perimeter of driveways to help with water runoff. Since concrete is fairly impermeable, it is possible to have excess standing water. The inclusion of drain rock can assist in whisking away excess water quickly and efficiently. Oftentimes, when a driveway is bordered directly with topsoil, that topsoil can get over-saturated, and you’ll find yourself with a flooded lawn. With drain rock bordering a driveway, creating a separation between it and your lawn, that supplemental drainage power can help reduce the risk of standing water damaging your property.

Garden Landscaping

This application is where the versatility of drain rock is helpful. Drain rock used in place of mulch in a garden area is a great blend of form and function. Drain rock helps with water absorption, while simultaneously preventing moisture from escaping, helping plants thrive. Unlike mulch, drain rock won’t blow away with a strong gust of wind. Drain rock is also very useful for preventing soil erosion in areas that are prone to receiving a lot of water. You should consider what type of plants you plan on having near stone or gravel landscaping, since drain rock is a natural insulator and collects a lot of heat. Some plants are more susceptible to this, and should be carefully considered before going all-out with drain rock landscaping.

Topcoat For Parking Lots & Walkways

Using a smaller, angular drain rock, like ⅜” chipped rock, can help keep parking lots and walkways free of mud and muck. Rather than using a smoother rock, the chipped architecture of these rocks helps to keep them stable and in place, which is ideal for high-traffic areas. This could be a more feasible idea for parking areas where concrete could be difficult to pour, or for aesthetic reasons as well.

Leach Fields

Drain rock is essential for the proper function of leach fields, or drain fields, which is part of the septic system. Using drain rock between ¾” and all the way up to 2 ½” in diameter will allow for the proper amount of waste water to become diffused into the soil over time. Drain rock is very important for the health of your septic system, and paramount to keeping property safe from damage, or needing to replace your septic system. Contact one of our materials experts at MJS Materials if you have any questions regarding what type of drain rock is right for your leach field and septic systems.

Let MJS Materials Be Your Florida Material Supplier!

MJS Materials has been serving Florida for over 30 years, and we carry just about any type of rock material that you could ever need for your home or construction needs. If you need to buy rock in bulk, or you just need enough for a home project, we have a large fleet of both haulers and loaders that can deliver materials directly to your work site. If you have any questions regarding the usage of drain rock, its applications, or how it can be best utilized for you, contact us, and our materials experts will provide you with clear, knowledgeable answers. We look forward to hearing from you and getting started on your next rock project!


We’ve just scratched the surface as far as the possibilities for rock applications go, but we hope these explanations inspired you to give us a call! Here’s what to take away from this blog:

  • Drain rock is designed to help manage moisture and water flow around properties and landscapes
  • Drain rock can be functional, formal, or both!
  • The most common applications of drain rock include:
    • French drains, for keeping moisture away from foundations
    • Controlling water collection around driveways
    • Clever landscaping
    • Keeping parking lots and walkways free of standing water and mud
    • Maintaining the proper function of leach fields for septic systems
    • And more!