Skip to Main Content

The “Clay Bowl Effect”: What It Is and Why It Matters for Your Home

wet damp efflorescence in basement

Have you noticed basement leaks or water accumulation around your foundation? If so, it is crucial to address these issues promptly to prevent potential foundation damage.

While many factors can cause these problems, the clay bowl effect is a common culprit. This page explains the concept, illustrates how it affects your home and provides solutions for repair.

What Is the Clay Bowl Effect? 

The clay bowl effect refers to potential issues with standard foundation construction. Builders excavate an area slightly larger than the house’s footprint for the foundation and basement, then backfill the space around the completed foundation with the excavated soil.

This backfill is often looser and more porous than the undisturbed surrounding soil, creating a “clay bowl” shape where water can easily infiltrate and accumulate. The trapped water pressures the foundation walls, potentially causing cracks, leaks, and bowing basement walls.

What is Backfill?

Backfill is the soil material used to refill an excavated hole or trench. It involves refilling these areas in layers, typically starting after floor joist placement.

Types of backfill include coarse-grained soil, limestone screenings, trench backfill, CA7 bedding stone, CA6 base stone, 3-inch coarse stones, and commercial fly ash or furnace slag by-products. Functions of backfill include:

soil foundation
  • Supports the Foundation: Backfill provides lateral support for foundation walls, helping them resist pressure from surrounding soil.
  • Drainage Support: Properly compacted backfill promotes water drainage, preventing water buildup and reducing leaks and the clay bowl effect.
  • Stability: Backfill distributes weight loads from the building more evenly across the underlying soil.
  • Load-bearing Strength: Backfill can contribute to the overall load-bearing capacity of the foundation system in some cases.

Proper compaction is crucial to prevent water damage and the clay bowl effect.

Signs of Clay Bowl Effect Damage

Signs that your foundation may be experiencing damage from the clay bowl effect include:

man holding nose bad smell

If you notice these signs, contact a foundation repair specialist for an inspection and customized solutions to prevent further damage.

How to Fix the Clay Bowl Effect

There are several ways to address the clay bowl effect and its resulting damage, including:

interior drainage installation

Interior Drainage System

Interior drainage installation captures foundation water accumulation and directs it to a sump pump. The sump pump then pumps the water away from the home, alleviating foundation pressure.

Basement Wall Systems: JES Wall Anchors

Wall Anchors

Wall anchors, made from high-grade galvanized steel, stabilize the foundation and hold the walls in place, preventing further bowing. They are typically embedded in the soil near the foundation walls.

waterproofing installed in crawl space

Foundation Waterproofing

Basement waterproofing and crawl space encapsulation prevent outside water from seeping into your basement or crawl space. These professional systems include sump pumps, dehumidifiers, vapor barriers, and drainage matting.

Professional, comprehensive repair solutions from JES ensure your home remains safe and dry from damage caused by the clay bowl effect.

Protect Your Home with Professional Waterproofing Solutions

JES work truck and crew member with vapor barrier roll

At JES Foundation Repair, our experienced professionals provide comprehensive basement and crawl space waterproofing solutions. Contact us today to schedule a free inspection and receive a no-obligation quote. Let us help you protect your most valuable asset and give you the peace of mind you deserve.

    Contact Us For Your Free Inspection

    * All fields are required.

    Waterproofing FAQs

    We strongly advise against attempting to waterproof or repair your crawl space on your own. The crawl space can be a dangerous area, and temporary solutions from hardware stores are insufficient. Trust the experienced professionals at JES Foundation Repair for a thorough inspection and customized waterproofing solutions. Contact us to learn more and schedule a free inspection.

    While DIY solutions may be tempting, they often fall short and can be hazardous. Professional services provide durable and safe solutions. Contact JES Foundation Repair for a complimentary crawl space inspection and no-obligation estimate. 

    It’s recommended to regularly check your basement, especially after heavy rainfalls or during seasons with increased precipitation. Monthly checks can help you spot early signs of water intrusion, allowing for timely intervention. 

    Shaye Glisson

    Shaye Glisson

    Shaye is an SEO Content Writer for Groundworks with over twelve years of experience creating helpful content across various industries, including home services and retail. She is a Gulf Coast native and writes from her firsthand knowledge of the area's hurricane and flood impacts on the local community. In her free time, Shaye enjoys exploring the local food and music scenes.

    Publish Date:

    Last Modified Date:

    JES Foundation Repair service area map of the Mid-Atlantic region.

    Our Locations


    8361 Town Center Ct
    Nottingham, MD 21236


    311 Central Rd.
    Suite 2-02
    Fredericksburg, VA 22401

    Hampton Roads & NE NC

    2569 Quality Ct
    Virginia Beach, VA 23454

    Northern VA & DC

    7940 Gainsford Ct.
    Bristow, VA 20136


    309 Quarles Rd
    Ashland, VA 23005

    Southwest Virginia / Roanoke

    2033 Cook Dr.
    Salem, VA 24153

    Western Virginia

    456 Old Courthouse Rd
    Appomattox, VA 24522


    45 W Boscawen St,
    Winchester, VA 22601