Moisture Problems Under Your Slab? Here's How We Fix It

What Causes Moisture Under Your Slab—and How We Fix It

If you’re seeing signs of musty smells, flooring damage, or high humidity in your home, you might be dealing with moisture problems under your slab. In Louisiana—where humidity is high and the soil is unstable—this is a very common (and very fixable) issue.

At Cripps Foundation Service, we specialize in moisture control for slab-on-grade foundations throughout Calhoun, West Monroe, Farmerville, and nearby towns. This blog covers the causes, warning signs, and most importantly—how we fix it.

Why Moisture Builds Up Under Slab Foundations

Concrete slabs are strong, but they’re not waterproof. Over time, moisture from the ground can rise up through the slab or leak in from the sides. In Louisiana, this can be caused by:

• High groundwater levels
  
  
• Frequent rainfall
  
  
• Improper drainage or poor site grading
  
  
• Plumbing leaks under the slab
  
  
• No vapor barrier or outdated construction methods

5 Common Signs of Moisture Under Your Slab

1. Warped or Buckling Floors

If hardwood or laminate flooring is starting to lift, bubble, or separate, moisture might be the culprit.

2. Damp or Musty Odors

Moisture buildup under the slab can lead to mold or mildew—often noticeable by smell before sight.

3. Efflorescence (White Powder) on Concrete

This mineral residue forms when water moves through concrete and evaporates, leaving salt behind.

4. Visible Moisture or Standing Water Near Slab Edges

Any water pooling around your home’s perimeter is a red flag for future slab issues.

5. Cracks in the Slab

While not always moisture-related, cracks can allow water to seep upward or become worse with moisture exposure.

How We Fix Slab Moisture Problems in Calhoun, LA

At Cripps Foundation Service, we use a combination of moisture control strategies depending on your home’s needs. Here's what a typical repair might involve:

1. Install Vapor Barriers

For moisture rising up through the slab (vapor transmission), we install high-quality vapor barriers under or around the affected slab areas to prevent further intrusion.

2. Improve Drainage Systems

We often recommend:

• French drains to move water away from the foundation
  
  
• Gutter downspout extensions
  
  
• Surface grading to prevent water from pooling near the slab
  
  

These upgrades ensure water flows away from your home—not under it.

3. Seal Cracks and Expansion Joints

We use industrial-grade sealants to close cracks or joints where moisture may enter. This stops water and helps preserve the integrity of your concrete.

4. Slab Jacking or Re-leveling (If Needed)

If moisture has already caused settling, we may need to lift and stabilize the slab using piers or foam injection techniques to correct the structure and prevent further movement.

5. Address Plumbing Leaks

If your moisture problem stems from a plumbing leak, we work with trusted local plumbers to locate and repair the line, followed by soil stabilization and slab repair as needed.

The Long-Term Effects of Ignoring Moisture Under Your Slab

Letting a moisture problem persist can lead to:

• Mold and mildew growth
  
  
• Structural damage or sinking
  
  
• Higher energy bills due to humidity
  
  
• Poor indoor air quality
  
  
• Decreased property value
  
  

If you’ve noticed repeated floor issues, humid conditions, or unexplained odors, don’t ignore it—let us assess the root cause.

FAQs About Slab Moisture and Repairs

How much does it cost to fix slab moisture issues?

Most moisture repairs range from $1,500 to $6,000, depending on the extent of the damage and which systems are needed (barriers, drains, re-leveling, etc.).

Do I need a vapor barrier in Louisiana homes?

Yes. High humidity and groundwater make vapor barriers critical for protecting your slab and flooring in Louisiana homes.

Will homeowners insurance cover moisture repairs?

Typically, not unless caused by a covered event like a burst pipe. We can help document the issue if an insurance claim is possible.

How long does a typical repair take?

Most moisture control projects take 1–2 days, though more complex foundation jobs may require more time.

Serving North Louisiana With Trusted Slab Moisture Control

Cripps Foundation Service has been solving slab and moisture issues for over 40 years across:

• Calhoun
  
  
• Swartz
  
  
• West Monroe
  
  
• Grambling
  
  
• Farmerville
  
  
• Choudrant Village
  
  

We’re a small, family-run business that believes in doing the job right the first time.

Call (318) 680-9300 or email us at macsamillion@hughes.net to schedule your free moisture inspection.
Open Monday–Saturday, 7am–7pm.