Steel Reinforcement (Rebar) Explained

Professional Pool Company — The Structural Framework Behind Every Gunite Pool

Steel reinforcement, commonly referred to as rebar, is one of the most important structural components of your gunite pool. It serves as the internal skeleton of the pool shell and ensures long-term strength, stability, and durability.

This article explains what rebar is, why it matters, and how we install and inspect it before the gunite phase.

⭐ 1. What Is Rebar and Why Is It Needed?

Rebar is a network of steel bars tied together to form a rigid grid inside the pool shell.

Gunite (or shotcrete) is extremely strong on its own, but when combined with steel reinforcement, it becomes a reinforced concrete structure engineered to last decades.

Rebar provides:

✔ Structural strength

✔ Crack resistance

✔ Shape stability

✔ Flex support during soil movement

✔ A strong bond for the gunite shell

Together, steel and gunite create a durable monolithic shell.

⭐ 2. How Rebar Is Installed

Once excavation is complete, our steel crew builds the steel cage directly inside the hole.

This includes:

• Horizontal rebar around the pool walls
• Vertical rebar for structural support
• Grid spacing based on engineering
• Reinforcement around corners and stress points
• Extra steel around steps, benches, and sunshelves
• Forming the spa structure (if applicable)
• Tying bars together with steel wire
• Ensuring proper clearance for gunite thickness

The steel cage must be structurally correct before gunite is applied.

⭐ 3. Engineering Determines Steel Placement

Rebar is not installed randomly — every pool is engineered before construction.

Your engineering plans specify:

• Bar size (usually #3 or #4)
• Spacing (typically 6”, 8”, or 10” on center)
• Double-mat or single-mat requirements
• Bond beam reinforcement
• Extra steel for spas and deep ends
• Locations needing additional load support
• Steps, benches, and curves
• Water features or retaining walls

This ensures your pool meets local building codes and structural standards.

⭐ 4. The Bond Beam — Extra Strength at the Top of the Pool

The upper portion of your pool (the bond beam) contains heavier reinforcement because it supports:

• Tile
• Coping
• Decking
• Screen enclosure footers (if applicable)
• Waterline stress points

A thicker, stronger bond beam prevents movement and cracking later.

⭐ 5. The Importance of Proper Spacing & Chair Supports

Rebar must be suspended off the dirt using chairs or spacers, ensuring gunite fully encases it.

Proper coverage:

• Prevents rust
• Increases shell lifespan
• Maintains structural strength
• Ensures the rebar doesn’t shift during gunite

Gunite must surround the rebar on all sides for correct structural performance.

⭐ 6. Additional Reinforcement for Spas & Water Features

Spas require:

• Hoop steel
• Tighter spacing
• Additional vertical steel
• Structural support around spillways

Water features (walls, scuppers, raised beams) require:

• Extra rebar
• Tied columns
• Reinforced raised beam structures
• Stress-point reinforcement

These areas carry additional water weight and require added rigidity.

⭐ 7. Electrical Bonding of the Steel Grid

Rebar is tied into an electrical bonding system for safety.

Your steel must be bonded to:

• Plumbing
• Equipment pad
• Pool water (via bonding lugs)
• Any metal items (rails, ladders, etc.)

Bonding protects against stray voltage and is required by code.

⭐ 8. County Inspection Before Gunite

Before gunite can be applied, the county must inspect the steel cage.

During inspection, reviewers check:

✔ Rebar spacing

✔ Bar overlap (“lap length”)

✔ Chair supports

✔ Electrical bonding

✔ Proper tie wire

✔ Engineering compliance

✔ Structural reinforcement at stress points

✔ Correct shape and depth

✔ Spa steel and shell layout

Gunite cannot begin until the steel configuration meets all requirements.

⭐ 9. What Homeowners Can Expect to See

When steel is completed:

• The pool looks like a perfectly shaped “basket” of steel rods
• Steps, benches, and sunshelves are clearly defined
• Spas and raised features are fully framed
• All bars are tied securely
• Rebar appears elevated from the soil
• The plumbing and main drains are in place

This is the final stage before your pool becomes a solid structure.

⭐ 10. Why Rebar Quality Matters

Proper steel reinforcement prevents long-term issues such as:

• Structural cracks
• Beam separation
• Shell movement
• Raised beam shifting
• Step or bench failure
• Weak spa walls
• Stress cracking during soil expansion

It is one of the key reasons gunite pools last 30+ years when built correctly.

⭐ Summary: Steel Reinforcement Is the Backbone of Your Pool Shell

Rebar provides the shape, strength, and durability your gunite pool needs. When combined with engineered plans and skilled steel installation, it forms a structural system designed to withstand:

• Weight
• Water pressure
• Soil movement
• Florida weather
• Decades of use

Steel reinforcement is one of the most important — and most overlooked — steps in building a high-quality pool.

⭐ Have Questions About Your Steel Phase?

We’re always here to explain your engineering plans and walk you through the process.

👉 Ask us anytime during the build.

Updated on: 28/11/2025