Table of Contents

Key Takeaways

• Coastal Louisiana soil expands, shrinks, and holds moisture, which can cause concrete to shift.
• A properly compacted gravel sub-base helps prevent uneven settling.
• Rebar strengthens concrete and reduces cracking in moving soil.
• Good drainage protects slabs from water-related weakening.
• Even small slab shifts can increase fall risk for seniors.
• Proper preparation protects safety, comfort, and long-term property value.

Concrete looks strong and solid. But in coastal Louisiana, what happens under the slab matters just as much as the surface you see. In Metairie and the Greater New Orleans area, the ground is often soft, wet, and made of clay. That can cause patios, walkways, and carports to sink or crack over time.

The USDA Soil Survey for Jefferson Parish shows that much of the soil here drains poorly and does not hold heavy weight well. The Louisiana Geological Survey also reports that parts of the region continue to sink slowly over time. These conditions make proper concrete preparation very important.

For homeowners age 65 and older, stable concrete is not just about looks. It helps prevent falls and keeps walkways safe.

Why Is Louisiana Soil Hard on Concrete?

Clay soil expands when it gets wet and shrinks when it dries. This constant movement pushes and pulls on concrete slabs.

Many homes in Jefferson Parish are also in FEMA flood zones. Heavy rain and high groundwater keep soil wet for long periods. Wet soil is weaker soil.

If the ground moves, the slab above it can crack or tilt.

Why Does Uneven Concrete Matter for Seniors?

The CDC reports that falls are a leading cause of injury for adults over 65. Even a small height difference—just half an inch—can cause someone to trip.

Here is a simple example:

A homeowner adds a patio. The soil was not compacted well. After two rainy seasons, one corner sinks slightly. Now there is a small raised edge. That edge becomes a tripping hazard when walking outside.

What started as a small shift becomes a safety problem.

What Is a Sub-Base?

A sub-base is the layer placed between the natural soil and the concrete. It supports the slab and helps with drainage.

It does two main things:

• Spreads weight evenly
• Helps water drain away

The American Concrete Institute recommends using compacted gravel under slabs to reduce uneven settling.

Without a proper base, cracks are more likely.

What Materials Work Best Under Concrete?

Crushed limestone or gravel works well because it:

• Supports heavy weight
• Drains water
• Reduces soil movement

Clay alone should not be used because it holds water.

How Thick Should the Base Be?

In soft Louisiana soil, 4 to 8 inches of compacted gravel is common for patios and driveways. Heavier loads may require more depth.

Thicker base layers spread weight better and reduce sinking.

Why Is Compaction So Important?

Compaction presses soil and gravel tightly together. This removes air gaps.

If soil is loose, water fills the empty spaces. Later, those spaces collapse. The slab above them can sink.

Think of it like stepping on a pile of dry sand versus packed sand. Packed sand holds better.

Heavy equipment is used to compact the base evenly before pouring concrete.

What Does Rebar Do?

Concrete is strong when weight pushes down on it. But it cracks when pulled or bent.

Rebar is steel placed inside the slab. It helps hold the concrete together if small cracks form.

The American Concrete Institute sets rules for using reinforcement to improve slab strength.

In areas where soil moves, rebar adds long-term stability.

Is Rebar Better Than Wire Mesh?

Rebar is stronger than wire mesh. Wire mesh can shift during installation. Rebar stays in place and provides better support in moving soil.

Where Should Rebar Be Placed?

Rebar must sit in the middle of the slab, not on the ground. Small supports hold it up during the pour.

If it rests at the bottom, it will not strengthen the slab properly.

Why Does Drainage Matter?

Water weakens soil. If water collects around a slab, the ground underneath softens.

Proper grading slopes water away from the slab. This protects both the concrete and nearby structures.

In places like Metairie, good drainage is part of long-term stability.

Signs of Poor Concrete Preparation

Watch for:

• Cracks wider than a thin hairline
• Edges that are uneven
• Water pooling on the surface
• Gaps between slabs and walls

These signs often point to base or drainage problems.

Questions to Ask Before Installing Concrete

Before starting a project, ask:

• What material will be used under the slab?
• How thick will the base be?
• How will the soil be compacted?
• Will rebar be used?
• How will water drain away?

Clear answers show experience and planning.

Why Professional Installation Matters

A stable slab supports everyday life. It keeps outdoor spaces safe for walking and gathering.

For retirees using savings for home upgrades, long-lasting work protects both comfort and property value.

When concrete is installed with proper base preparation, reinforcement, and drainage, it can handle the demands of coastal Louisiana soil.

When You Hire Us, We’ll Be There! From start to finish, careful preparation leads to safer, longer-lasting results.

Maria Larson

With over 25 years in the flooring industry, I’ve dedicated my career to helping people transform their spaces. Growing up in Florida, I worked alongside my parents in their flooring store, learning the trade from the ground up—literally. From the warehouse to sales, I gained firsthand experience in every aspect of the business, cultivating a deep appreciation for quality craftsmanship and customer service. I thrived on interacting with clients, guiding them through design choices, and bringing their vision to life. When my parents retired, I proudly took over the family business, continuing their legacy while making it my own. My passion lies in creating beautiful, functional spaces and ensuring every customer feels confident in their choices.

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