How to Build a Concrete Retaining Wall

How to Build a Concrete Retaining Wall: Complete Guide

Building a concrete retaining wall requires proper footing below the frost line, vertical rebar, and drainage gravel behind the wall to prevent hydrostatic pressure. Retaining walls fail without proper construction. This guide covers the essential requirements for building a successful retaining wall.

Essential Requirements

Three critical elements are required:

1. Footing Below Frost Line

• Why it matters: Prevents frost heave from lifting wall
• Depth: Must be below frost line (varies by location)
• Width: Typically wider than wall base
• Foundation: Provides stable foundation for wall

2. Rebar Verticals

• Why it matters: Provides structural strength
• Placement: Vertical rebar throughout wall
• Connection: Tied to footing rebar
• Required: Essential for structural integrity

3. Drainage Gravel Behind Wall

• Why it matters: Prevents hydrostatic pressure buildup
• What it does: Allows water to drain
• Prevents failure: Hydrostatic pressure can push wall over
• Critical: Most common cause of wall failure

Step-by-Step Construction

1. Excavate footing: Dig footing trench below frost line
2. Form footing: Build forms for footing
3. Install rebar: Place rebar in footing, extend verticals
4. Pour footing: Pour concrete footing
5. Build wall forms: Construct forms for wall
6. Install vertical rebar: Place vertical rebar, tie to footing
7. Pour wall: Pour concrete wall
8. Backfill with gravel: Place drainage gravel behind wall
9. Install drain pipe: Place perforated drain pipe if needed

Why Drainage Gravel is Critical

Without drainage gravel:

• Water builds up: Water accumulates behind wall
• Creates pressure: Hydrostatic pressure develops
• Pushes wall: Pressure can push wall over
• Wall fails: Wall collapses

With drainage gravel:

• Water drains: Water flows through gravel
• No pressure: Prevents pressure buildup
• Wall stable: Wall remains stable

The Bottom Line

Building a concrete retaining wall requires three essential elements: footing below frost line (prevents frost heave), vertical rebar (provides strength), and drainage gravel behind wall (prevents hydrostatic pressure). Missing any of these elements leads to wall failure. Always include all three for a successful retaining wall that will last.

Need help building a retaining wall? Contact Local Concrete Contractor. We build retaining walls correctly with proper footings, reinforcement, and drainage.