Hydrostatic Pressure Destroying Your Basement? Here’s How We Fix It

Hydrostatic pressure is the force exerted by water at rest. It impacts basements and foundations because they are partially underground. The weight of water in the soil, called the water table, is constantly pushing against the foundation. This pressure can cause several problems, including cracks, leaks, and bowing walls.

If you are experiencing the impact of hydrostatic pressure on your basement, you likely need basement waterproofing services. JES Foundation Repair can help!

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What Is Hydrostatic Pressure?

Hydrostatic pressure is a fundamental concept in various fields, including home repair. It’s crucial to understand its meaning and implications for basement health.

Hydrostatic pressure is the force exerted by water at rest. The term combines “hydro” (water), “static” (indicating a certain state), and “pressure” (force). This force originates from the weight of water, which is about eight pounds per gallon. A cubic foot of water, containing approximately 7.5 gallons, can exert over 60 pounds of pressure.

Hydrostatic Pressure and Your Basement Foundation

Water naturally exists in the ground, forming a “water table.” Since homes are partially underground, they constantly experience pressure from this water table. The water table’s height can fluctuate, but it’s uncommon for it to be lower than an entire house, making hydrostatic pressure a persistent concern.

Hydrostatic pressure isn’t limited to groundwater. Water above ground, such as rain, plumbing leaks, or flooding, also exerts pressure. This explains why flooding can be so damaging – a floor may not withstand the sudden weight of hundreds or thousands of pounds of water. While above-ground hydrostatic pressure isn’t always a concern, it’s crucial to address it when it occurs.

Impacts of Hydrostatic Pressure

Hydrostatic pressure can significantly impact a basement in several ways:

Bowing Walls: As hydrostatic pressure builds, it pushes against the foundation walls, causing them to bulge inward. Over time, this can lead to horizontal cracks, allowing water to seep in.
Cracks in the Floor: The weight of floodwater can exploit existing weaknesses in the basement floor, leading to cracks. Additionally, expanding soil beneath the foundation, due to increased hydrostatic pressure, can crack the floor from below.
Ground-Level Windows: Improperly installed ground-level windows are susceptible to leaks caused by hydrostatic pressure. Regular windows, not designed for basement use, may not withstand rain and snow, resulting in water seepage.

Rain’s Impact on Hydrostatic Pressure

Rain and subsequent flooding can significantly increase hydrostatic pressure, leading to multiple basement problems:

Increased Weight from Flooding: Flooding, both inside and outside the home, adds significant weight, increasing the hydrostatic pressure on the foundation.
Rising Water Table: Rainwater seeping into the ground raises the water table, even temporarily, adding to the hydrostatic pressure on the basement.
Structural Damage from Natural Disasters: Natural disasters can weaken a basement’s structure. Subsequent rainfall then adds to the hydrostatic pressure, increasing the likelihood of basement leaks.

Identifying Hydrostatic Pressure Issues:

Several indicators suggest potential hydrostatic pressure problems:

A darkening hole in the concrete foundation
Water droplets forming on an underside of a secured plastic sheet
Moisture meter reading exceeding 5%

Understanding and managing hydrostatic pressure is key to maintaining a healthy, leak-free basement.

Solutions to Stop Hydrostatic Pressure

technicians adding vapor barrier to basement walls

1. Basement Waterproofing Measures

Interior Drainage: Installing interior basement drains (AKA “French Drains”) in your basement is probably the most impactful way to counteract hydrostatic pressure on your basement
Sump Pumps: While not a solution to eliminate hydrostatic pressure, sump pumps effectively remove water that has already entered the basement, mitigating damage.
Vapor Barriers: Installing a waterproof barrier between the concrete and the water source is crucial. This prevents the foundation from absorbing moisture from the ground. Water barriers are effective against high water tables and poorly drained backfill.

technician applying carbon fiber straps to basement wall

2. Other Measures

Structural Reinforcement: Addressing existing damage, such as bowed walls or cracks, by installing carbon fiber straps, steel I-beams, and/or wall anchors helps maintain the foundation’s integrity and prevent further water intrusion.
Functional Gutters and Proper Yard Grading: A well-maintained guttering system is vital. Downspouts should channel water away from the foundation, preventing soil saturation. Ensuring appropriate grading around the house is essential. This helps disperse water slowly across the landscape, minimizing hydrostatic pressure.

Combining these solutions is often the most effective approach to managing hydrostatic pressure. If problems arise during or after construction, professional assistance is recommended.

Conclusion: Hydrostatic Pressure and its Impact

In case you’re having problems with hydrostatic pressure during or after construction, you should contact professional help. Our team at JES Foundation Repair can come down to your home in Virginia Beach, Virginia, and offer you a free inspection. Later on, they’ll discuss methods and techniques to keep your home safe for years to come.

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Hydrostatic Pressure FAQs

What is hydrostatic pressure?

Hydrostatic pressure is the weight of water when it’s at rest. It is a big source of foundation problems and basement waterproofing problems. Poor drainage, clay soil, underground water sources and extreme weather all contribute to hydrostatic pressure.

The water collecting around your foundation has to go somewhere. And if the footing drains are clogged, then the water can go into your basement. The hydrostatic pressure pushes against your basement foundation and will eventually cause cracks, leaks, acid damage and other problems.

How Does Hydrostatic Pressure Affect a Home?

Hydrostatic pressure is something that every home has to deal with. After all, it is simply the combined weight of the soil and the water that it contains. This is something that every home is designed to cope with to a certain extent. Hydrostatic pressure only really causes problems when it reaches levels that are unbearable for your property. When this happens, the damage can be significant and widespread.

The reason that hydrostatic pressure causes issues like fragmentation, cracking, movement, and bowing in basement walls is because the pressure that it applies is lateral in nature. Concrete, as a material, is incredibly durable and strong. It can hold huge amounts of weight and has incredibly compressive strength. However, its tensile strength is a fraction of this. In short, concrete cannot stretch and lateral pressure forces it to flex in ways it is not made to.

When this happens, it is common for affected concrete structures and surfaces to move, crack, lean, or buckle. Once the structure of your home has been damaged, furthermore, the water in the soil will start to seep through these cracks and into your home. This, in turn, can cause increased humidity, dampness, mold formation, wood rot, and many other moisture-related issues, as well as making your home far more inviting to pests of all kinds.

How Long Does Basement Waterproofing Last?

As mentioned, some waterproofing solutions are temporary, whereas others can last longer if they’re more comprehensive. The type of waterproofing that involves interior drainage installed by a reliable contractor is a more permanent solution. Comparatively, sealant waterproofing lasts between one and two years, depending on the type of sealant you used.

Michael Wilcher

Michael Wilcher is the Content Lead at Groundworks, helping us to answer all of our customers biggest questions about foundation repair, basement waterproofing, crawl space encapsulation, and concrete lifting. In his free time, Michael enjoys collecting vinyl records, watching Formula 1 Racing, and reading philosophy. He holds an MPhil from the University of Cambridge.