Soil washout refers to the erosion of soil due to water running along the topsoil. The water loosens up and displaces the soil’s particles. Said particles are then washed down the slope in the stream of water.
The reason you should care about soil washout as a homeowner is because the slabs that make up your driveway, patio, pool deck, and walkways are supported by a layer of soil. Even your foundation depends on an even layer of soil in order to stay stable.
The conditions of the soil on your property will affect how the concrete structures of your home behave. Soil washout displaces the soil that exists under your concrete, essentially removing its base. An uneven base can destabilize concrete structures and cause them to crack and break. Let’s chat more about what causes soil washout, and how it affects your property.
What Causes Soil Washout?
The erosion of soil occurs every single day on your property. Every time you step on your lawn, there is some sort of displacement of your soil. Even when you hose down your flower beds, the droplets of water that land on your soil causes splash erosion.
However, that kind of erosion is very different from soil washout. Soil washout is caused by a stream of water going down a slope and taking the topsoil with it. Washout is the kind of erosion that displaces soil very rapidly, especially in places with high elevation like inland Virginia, West Virginia, and Maryland. While it is possible for soil to erode with standing water, with soil washout, there needs to be a slight incline in order for the water to flow and wash out the soil.
This happens very easily on a homeowner’s lawn since residential terrains are rarely ever even, especially after a few years. Storms, rain, human activity, and other factors change the slope of a terrain quickly. If your property is at least five years old, then there are quite a few places where soil washout can occur. Soil washout happens because of the following:
Tropical Storms
Mid-Atlantic states see a lot of soil washout because of all the tropical storms. From the beginning of June all the way until the end of November, hurricanes run rampant around that region. The heavy rainfall that comes with these storms is the number one cause of soil washout in the area, and, unfortunately, it happens every year. This means that the soil on your property washes out consistently over the course of a few years.
Not just rain, but floods are a big problem too. Even areas where the tropical storms aren’t severe see heavy soil washout in the aftermath of the hurricanes. Washington, D.C., thanks to its inland location, has mild hurricanes pass through every year. The rains from the hurricanes flow down from areas with higher elevation and cause flooding.
Water is fully capable of getting under the concrete slab you have around your property. The more water that flows toward it, the more it will erode the soil. The more the terrain around your home changes with every tropical storm, the more exposed the soil under the slab is.
Terrain
The Appalachian Mountains are what divides West Virginia and Virginia. Toward the middle of these two states up until the border where they meet, the elevation is incredibly high. Soil washout occurs on sloped terrain when water flows down.
Anytime there’s rain, there will be some sort of soil washout if the terrain your home sits on is sloped. Virginia Beach’s terrain is flatter, but there can still be some intense washout due to the soil.
Soil Type
How quickly soil washes out depends on the type of soil it is. The majority of the soil in Mid-Atlantic states like Maryland and West Virginia are sandy, fine-grain soils. Among them are soils from the series Sassafras, Tetotum, Ramsey, Berks, and Altavista.
These soils have an advantage over expansive soils farther south of the country in that they do not retain water. However, this means that they wash out easily. Because of their lack of clay content, sandy soils do not compact easily, meaning that they are loose and shifty.
Poor Yard Drainage
As a homeowner, making sure you have proper yard drainage is paramount. A lack of control over where water flows in your yard is one of the reasons soil washout destroys your yard in just a few short years.
Every yard has a negative or positive grade. Negative grade means that water flows toward your home. In severe cases, the perimeter of your home will flood every time it rains. A positive grade, on the other hand, means that water flows out and away from your house.
While having a positive yard grade is desirable, when you have sandy soils, letting gravity handle drainage is not a good idea. Regardless of whether your property’s terrain is slightly convex or concave, there will be soil erosion. Remember, as long as water is slowing down an incline, it will displace the topsoil.
Given how much it rains during the tropical storm season in the Mid-Atlantic and the sandy soil of the region, you definitely need to invest in a good yard drainage system. Yard drainage installations make sure that the water that lands on your yard gets collected and drained out before it streams down your property. Good foundation drainage is also something to be considered since there are installations like sump pumps that can collect the moisture in the immediate vicinity of your home.
Lack of Foliage
A lack of grass, flowerbeds, and other kinds of vegetation can lead to soil washout. Plants are capable of binding topsoil by dispersing organic material. The less organic material soil has, the grainier it will be and the more it will wash out when met with a gush of water. Foliage can also provide soil with some cover from rainfall as well as block water to prevent large streams.
How Soil Washout Affects Your Concrete Sidewalk or Driveway
Soil washout might not seem like a big deal in the grand scheme of things. However, it has a detrimental effect on the concrete on your property.
Settling is the erosion of soil under concrete that leads to an uneven structure. An even layer of soil supports your concrete slabs. If that layer becomes uneven due to soil washout, then your slab will no longer be supported properly. Craters that come from soil washout are called sinkholes. When there’s a sinkhole under the concrete, the slab will eventually settle against the sinkhole as it buckles under whatever pressure is placed on it.
Concrete slabs are typically only four inches thick, so once they settle, they crack very easily. Concrete has terrible tensile strength, meaning it cannot handle intense, isolated pressure. In order to handle a large amount of weight, it has to be able to disperse the pressure throughout its entire build. However, the only way it’s able to do that is if it has an even foundation. The moment a slab rests upon an uneven foundation, it cannot disperse pressure evenly, causing it to crack.
In the beginning, a settling slab might only wobble when stepped on or the unevenness will be minimal. It will only get worse with time, especially if you live in a place that experiences heavy flooding like Washington, D.C. and Richmond, VA where flooding is a consistent, yearly occurrence due to storms.
The concrete around your home most likely to settle are those that have a slight incline, since the soil underneath will experience more severe washout. Depending on how the terrain on your property slopes, this could be your driveway or the various pathways in your yard. If there’s already an incline, then a cracked, settled slab will make navigating these places a lot harder.
How Soil Washout Affects Your Foundation
The concrete slabs outside your home aren’t the only things affected by soil washout. Soil washout can erode the soil around your foundation until you begin to have structural problems. If you are seeing signs of soil washout with the slabs around your property, then it would be wise to check your foundation for signs there too.
Soil washout causes foundation settling, which changes the infrastructure of your entire house. When settling, half of your foundation is resting against a sinkhole. If the base your house relies on to stay upright is not stable, then you will experience the following problems:
- Bowing basement walls
- Exposed foundation concrete
- Ceiling and wall cracks
- Jammed doors and windows
- Stair-step cracks along mortar
- Tilting chimney
And in the specific case of slab foundations:
- Cracked kitchen and bathroom tiles
- Indoor flooding
- Chipping floorboards
If you see the signs of foundation settling, calling a professional is the way to go. These structural changes that come as a result of settling are extremely disruptive and only get worse over time. To avoid living in an unstable house and paying exorbitant rates for repairs, be sure to keep an eye out for soil washout.
How To Fix Concrete Settling
Concrete settling is a terrible thing. Not only does it ruin your property’s look, but also it’s a safety hazard. You’re more likely to trip when walking on an uneven surface, and all the wobbling and cracks don’t help, either.
Luckily, concrete settling isn’t something you have to live with for long if you know who to call. Concrete settling can be resolved with a simple yet life-changing solution called PolyRenewal™.
PolyRenewal™ is a concrete lifting method that uses polyurethane foam to permanently solve your soil washout problems. Here’s how it works:
Contractors drill multiple small holes into the concrete slab. Service techs inject polyurethane foam under the slab until it fills the sinkhole and raises the slab. After making sure that there’s enough foam under the concrete and that the slab is properly leveled, the holes are covered up and the foam is left to cure. Depending on the scope of the project, this can take anywhere between 5 and 15 seconds.
Overall, the process is pretty straightforward. Don’t let the simplicity fool you, though— PolyRenewal™ does more than simply lift the slab. Because of the way the material interacts with the soil, it prevents settling indefinitely. The entire reason why settling occurrs in the first place is because the slab did not have a proper foundation. It’s not enough to replace the soil and lift the slab if the material used is going to wash out like the soil first did.
Polyurethane foam is a polymer that does not erode with time. It’s durable and stable; it’s the perfect foundation material for a concrete slab in a Mid-Atlantic state. It’s waterproof and non-permeable, so it doesn’t fall into the traditionally erosive cycle of freeze-thaw. With mudjacking, an older method of concrete lifting, there’s always a chance that the cement mixture used for the job will erode over the years.
Unlike other concrete lifting methods, PolyRenewal™ does not displace the soil with its weight. It’s able to support over 100 tons of pressure while being light weight enough to prevent displacement. This is important for the sandy soils of Virginia Beach and Roanoke, VA. Loose, sandy soils are too grainy and shifty to support weight without falling apart.
Wash Out Soil
FAQ's
If you’re dealing with a settling foundation due to soil washout, then you might want to know what your options are. If you do some research, then you’ll hear talk of concrete piers for your foundation, which are meant to stabilize your home so that it won’t settle anymore.
However, concrete piers as a foundation support system are outdated and unreliable. There are plenty of modern options for your foundation that last longer than concrete piers and actually give you bang for your buck.
- Why Concrete Piers Don’t Work
Concrete piers are not capable of lifting your settling foundation. The way they are made and put into place does not allow contractors to exert the required pressure to lift your foundation back into place. What they are meant to do is simply stop the settling and keep your home in its current position; however, this isn’t even a guarantee. This is because the foundation should not rely on the pier system itself to stay stable but rather on the load-bearing soil deep beneath your property.
Concrete piers are not able to reach load-bearing soil depths because they cannot be made long enough to do so. The longer and thinner the concrete pier is, the less weight it’s able to support due to its low tensile strength. Making it bigger won’t help either since the bigger the pier is, the more likely it is to experience skin friction. Once a concrete pier feels the pressure caused by the skin friction, it crumbles under the weight of the house.
- What You Can Do About Foundation Settling
At JES, we offer multiple solutions that are able to reliably stabilize your foundation and possibly lift it back into place as well. We have helical and push piers, as well as slab piers for slab-on-grade. They are long rods made of galvanized steel that are attached to your foundation and buried deep underground. Because of their sleek design, they are capable of reaching load-bearing soil and transferring the weight of your foundation to those soils. These pier systems can mechanically exert pressure onto your foundation until it’s stable once more.
If you have a slab foundation, then we have another repair option for you. You can use PolyRenewal™ to lift your foundation back into place like you would any other slab. It depends on the needs of your home, but utilizing polyurethane foam can lift your foundation until it’s even again without the need for excavation or heavy machinery. The device we use to inject PolyRenewal™ is handheld and small, meaning that it can be used in smaller areas, like your bathroom, if need be.
Replacing and repairing is part of being a homeowner. Knowing when to replace and when to repair is crucial if you want to save money.
Many homeowners believe that something that has been repaired once is bound to break even faster, so replacing is the way to go if you want to reset the object’s lifespan. While that may be true for electronics, it isn’t for the concrete slabs around your home.
- When to Repair
No matter the severity of the settling, concrete slabs should be repaired and lifted. Remember, when a slab settles, it’s never because there’s a problem with the slab itself. While the soil layer under your slab was evenly spread out at first, external forces like soil washout cause it to erode.
If your slab settles, it will not lose its strength after being repaired. Concrete lifting solutions like PolyRenewal™ work to prevent further erosion and provide the slab with reliable support. Even the holes drilled for polyurethane injections are incredibly small (about the size of a penny) and cause minimal disruption to the concrete’s structure. After repairs, you can put as much weight on your slab as you want, without any problems.
- When to Replace
It’s wise to look into repairing your slab instead of replacing it, especially if you want to save money. Not only is replacing a slab more expensive than repairing, but also it doesn’t solve your soil washout problems. You replace the slab and place a new, even layer of soil under it; but, that soil will wash out with time, and you’ll be having the same problems again.
That’s not to say replacing is out of the question. If the slab has cracked to the point where it cannot be put back together, then you’re better off replacing it. Polyurethane foam is not a glue that can unite pieces of concrete, so while it can lift a bigger piece that has broken off, it cannot do anything for the smaller, cracked pieces.
Those that have problematic soil might be wondering what can be done about soil washout. The most obvious answer might be to hire a landscaping expert and replace the sandy soil on your yard with a more stable soil. However, replacing your soil might not give you the results you want.
- Why Replacing Your Soil Won’t Work
If you look it up, loam soil is considered to be the least problematic soil of all. It’s an equal mix of sand, silt, and clay soil. It doesn’t have enough clay to experience severe shrink-swell, and it’s not as shifty as sand soils. This makes it seem like a perfectly balanced soil capable of combating the worst of erosion. However, you should know that loam is mostly used in farming and not for property landscaping.
The characteristics of loam soils make them perfect for growing crops in undisturbed fields where their exposure to water is closely monitored by the farmers. A residential property is completely different. Human activity greatly alters the way loam soils behave. Not to mention, cities like Appomattox, VA and Baltimore, MD experience flooding on a regular basis. Despite the equal amounts of silt, sand, and clay, loam soils are still susceptible to washout when faced with large streams of water.
- What You Can Do Instead
Instead of replacing your soil, you can do something a lot less expensive and a lot more efficient instead. Contact your local experts to know what your options are for yard drainage, foundation waterproofing, and concrete slab repair. Equipping your home with the proper tools will raise the value of the property and give you long-term peace of mind.
Mitigating the damage caused by soil washout is a lot more effective than trying to prevent it altogether . Arm yourself with knowledge so that you’re able to identify the signs of soil erosion. Once you notice that something is off on your property, you’ll be able to take action before things get worse.
Call JES For Your Concrete Lifting Needs
Protect the concrete on your property by calling JES. We’ve been operating since 1993, helping homeowners keep their properties secure and livable. We service Baltimore, MA, Washington, D.C., Charleston, WV, and Virginia (Appomattox, Richmond, Roanoke, Manassas, Virginia Beach).
If you’re interested in PolyRenewal™ for your settling slab, then give us a call or use the online contact form on our website to set up a free inspection. One of our field agents will assess the damage and give you a rundown of what needs to be done as well as a repair quote.
