Skip to Main Content
AFS Crew in training

Foundation Waterproofing: Why Does It Leak?

Our solutions cover all surfaces of the basement, including the foundation walls, basement floors, and even wet crawl spaces.

Get A Free Quote

Understanding Foundation Flooding And How To Fix It — Permanently!

Basement Before
The white, chalky residue on these concrete walls, called efflorescence, is a sign of water in a basement or crawl space.

Flooding in basements and crawl spaces is common in homes new and old and is rarely a one-time occurrence. Once water has flooded through your foundation, you can be certain that it will happen again.

There are two important factors that contribute to basement leaking — the clay bowl effect and hydrostatic pressure.

We offer free waterproofing quotes in Alabama cities like Madison, Birmingham, Huntsville, Tennessee areas like Nashville and Chattanooga, Georgia areas like Columbus and Lookout Mountain, and in Mississippi areas like Biloxi. Call or e-mail us today to schedule an appointment!

The “Clay Bowl Effect” And Your Foundation

When your home was built, contractors began by digging a hole to make room for your basement and foundation a little larger than the space your home would need. The foundation would then be built inside this space, and the concrete floor would be poured.

Once the foundation was built, some of the excavated soil was used to fill in the gap around the outer edge of your foundation. This soil, known as “backfill”, was loose and fluffed from the excavation. Meanwhile, the untouched soil around it, known as “virgin soil”, may have been settling for hundreds, even thousands of years.

What does this mean for you? The backfilled soil surrounding your foundation will always be looser and more absorbent of water than the dense, hard-packed soil around it.

This forms a sort of “clay bowl” around your house — one that creates an artificial water table around your home. Water collects the most right around your foundation — exactly where you don’t want it to be.

Voids around basement wall during construction

Hydrostatic Pressure and Wet Foundation Soils

Hydrostatic pressure from fill soils expanding around basement walls

Water is heavy! As the soil around your home becomes soaked with moisture, the soil will expand, and the weight of the water will press on your foundation. This is known as hydrostatic pressure.

As hydrostatic pressure builds against your foundation, water will work its way into your basement or crawl space in any way possible. Water can make its way through concrete cracks in the walls or floors, through openings around pipes, through basement windows, or even directly through the porous concrete. If you have block walls, water may pass through the block and begin to fill the open cavities inside your walls.

However, the most common way that water enters a home is through the foundation wall-floor joint. We find that most flooded basements start with a leak here, where the floor and wall meet.

Waterproofing a Foundation in Alabama, Tennessee, Georgia, and Mississippi

The southeastern states are similar in basement construction (and problems).  How do you dry a wet basement? You must stop the water at its entry point.

Since most basements flood from the wall-floor joint, one of the most common ways to stop the flooding is to install a perimeter drainage system along the edge of the basement floor. This would collect the water and direct it to a sump pump, which would then discharge it out of your home.

However, at AFS Foundation & Waterproofing Specialists, we have an approach to solving water problems of all types. Our solutions cover all surfaces of the basement, including the foundation walls, basement floors, and even wet crawl spaces.

We offer free basement waterproofing estimates in Alabama, Tennessee, Georgia, and Mississippi. Contact us today to get started!


Request Free Inspection
Request Free Inspection


Birmingham, AL

(205) 286-5520
(205) 859-8550
130 Interstate Commerce Crt. Bldg. 100 & 200
Alabaster, AL 35007

Chattanooga, TN

(423) 212-8210
(423) 226-3582
214 Industrial Park Dr.
Soddy-Daisy, TN 37379

Huntsville, AL

(256) 344-6717
(256) 445-9070
2415 Jordan Road
Huntsville, AL 35811

Knoxville, TN

(865) 290-1305
(865) 290-1306
3028 E Governor John Sevier Highway
Knoxville, TN 37914

Mobile, AL / Biloxi, MS

(251) 250-1901
(251) 220-3457
3131 Hamilton Blvd.
Theodore, AL 36582

Montgomery, AL / Columbus, GA

(334) 209-5411
(334) 203-4899

Nashville, TN

(615) 246-7220
(615) 235-0525
1519 Heil Quaker Blvd.
LaVergne, TN 37086