When homeowners start dreaming about a backyard pool, they usually focus on the visual elements—the shape, the color of the pebble finish, maybe a waterfall feature they saw online. That’s natural. Those are the parts you’ll see every day.
But here’s what most people don’t realize: the parts you’ll never see are what determine whether your pool becomes a cherished family gathering space or an expensive maintenance headache.
Since 1964, Century Pools has built custom gunite pools across California, from celebrity estates to neighborhood backyards. Over six decades and multiple generations, the O’Neal family has learned that building a pool that lasts requires understanding what happens below the surface—literally and figuratively.
This guide walks you through the complete gunite pool construction process, revealing the invisible decisions and technical details that separate pools built to last from pools built to look good for a few years.
Why the Foundation Matters More Than the Features
The biggest gap between homeowner expectations and reality happens right at the beginning.
Most people think pool construction is primarily about aesthetics. They browse Pinterest, save photos of stunning pools, and imagine their backyard transformed into a resort-style retreat. The shape, the features, the finishes—these dominate the conversation.
But building a lasting, functional pool starts with site evaluation, soil assessment, drainage analysis, and structural planning. The invisible details—proper slopes, reinforcement, flow between the pool and your house—are what make your pool safe, durable, and enjoyable for decades.
Think of it like building a house. You wouldn’t choose paint colors before ensuring the foundation can support the structure. The same logic applies to pools, but it’s easier to overlook because you can’t see the foundation once construction is complete.
Site Evaluation: Reading the Land Before Breaking Ground
When Century Pools evaluates a potential pool site, the team looks beyond the obvious backyard space. They’re studying how the land behaves.
Red Flags That Require Special Attention
Several conditions tell an experienced contractor that a project needs modified engineering before anyone discusses pool shape:
- Soft or spongy soil that indicates poor load-bearing capacity
- Visible pooling after rain that reveals drainage problems
- Steep slopes that may require retaining walls
- Areas where erosion is likely based on water flow patterns
- Underground obstacles like utility lines or old foundations
- Drainage patterns that affect how water moves across your property
- Lot positioning relative to neighboring properties
These factors determine whether your pool will need extra reinforcement, engineered retaining walls, or modified plumbing to prevent long-term issues.
Here’s why this matters: Clay soils expand and contract as humidity levels change, which can endanger the pool’s structure, while sandy soils can erode or shift over time. Even more dramatically, groundwater can cause an empty pool shell to literally float out of the ground if not properly designed to counteract buoyant forces.
By identifying these conditions early, contractors can adjust the design and construction plan before the pool shape or features are even considered. This protects both your investment and your long-term enjoyment.
Excavation: Engineering the Foundation
Most people think excavation is just digging a hole in the ground. It’s not.
Strategic excavation is about engineering the foundation based on what you discovered during site evaluation.
A Real Example of Strategic Excavation
Consider a project where the backyard had hidden pockets of soft, shifting clay that weren’t obvious on the surface. During excavation, the Century Pools team didn’t just dig a generic hole. They carefully mapped and reinforced those weak spots, adjusting the depth and slope of the pool floor and walls to compensate.
That strategic approach ensured the shell would remain stable for decades, preventing the cracks, settling, or leaks that often appear in pools built without addressing soil issues.
This is the difference between excavation and engineering. One digs a hole. The other creates a stable foundation that accounts for soil conditions, water table levels, and long-term ground movement.
Problems can occur if you hit solid bedrock or if underground springs or a high water table begin leaking into the excavated area. These situations require dewatering methods to facilitate construction.
Hand shaping the sides of the entire pool during excavation ensures true consistency of gunite all around the pool and creates a solid foundation. This prevents issues from uneven surfaces that could compromise the shell’s integrity.
Steel Reinforcement: The Invisible Backbone
After excavation, you’ll see workers installing what looks like a tangled mess of steel bars throughout the pool cavity. If you’re watching from your back porch, you might wonder if all that steel is really necessary.
It is. And then some.
What Rebar Actually Does
The rebar isn’t just a grid sitting in the pool—it’s the structural backbone that gives the shell its strength and stability.
The precise layout, spacing, and connection of the bars ensure the pool can withstand soil movement, water pressure, and seasonal shifts without cracking. Swimming pools typically use reinforcing bars spaced at 12 inches on center each way, though many projects call for 8 or 6-inch spacing for added strength.
The steel is typically set 2-4 inches from the dirt wall and bent into position to wrap around steps and curves, following the shape of the dig. This flexibility allows pools with properly installed rebar to accommodate intricate designs with curves, steps, and custom features.
💡 Important: The rebar must be fully encapsulated within the gunite. Without proper encasement, voids can form in the concrete around the bars. These voids reduce the concrete section’s ability to carry loads, leading to cracks or, in extreme cases, failure of the pool shell.
Cutting corners during this phase—skipping bars, spacing them too far apart, or not tying them correctly—creates problems that won’t appear until years later. What most people don’t realize is that this invisible framework is what makes a pool last decades.
Careful attention during the steel reinforcement phase is far more important than the features you’ll see on the surface.
Gunite Application: Where Precision Becomes Permanent
When the gunite is being sprayed onto the rebar framework, you’re watching the moment when engineering becomes permanent structure.
The difference between an adequate shell and one built to last comes down to consistency, coverage, and precision.
How Gunite Works
Gunite is a dry mixture of sand and cement that travels through a hose, meeting water only at the nozzle. This late-stage water addition allows for meticulous control over consistency—an essential factor in crafting a smooth surface that will last for years.
The process is applied with so much pressure that a skilled nozzleman can spray gunite several days apart and still create a durable, attractive concrete surface without risking structural flaws.
What to Look For During Application
If you’re present during the gunite pour, watch for these quality indicators:
- The crew moves methodically rather than rushing through sections
- The surface appears uniform without gaps or thin spots
- Forms and angles match the intended design exactly
- Every wall and floor maintains engineered thickness
- The rebar is fully encapsulated with no exposed steel
- Slopes and curves are smooth and consistent
That careful attention during the gunite pour establishes the pool’s long-term structural integrity, even though the finished surface will hide all of this craftsmanship.
⚠️ Critical timing: Gunite typically takes 28 to 30 days to cure properly. The importance of properly water-curing gunite cannot be overstressed. If gunite dries prematurely without proper water-curing, it becomes brittle and loses much of its natural structural strength.
Plumbing and Equipment: The Long-Term Cost Decision
After the gunite cures, construction moves to plumbing and equipment installation. Most homeowners think this is straightforward—just connect the pipes and pumps.
But decisions made during this phase directly impact whether your pool is expensive or affordable to operate ten years from now.
Pipe Sizing and Routing
Proper pipe sizing and routing during plumbing installation creates a system that moves water efficiently, minimizes energy use, and keeps the pool balanced chemically.
Using 2-inch PVC on suction lines provides greater water flow and prevents cavitation, which occurs when the pump doesn’t get enough water due to undersized pipes. If pipes are too small, pumps are oversized, or circulation is poorly planned, you end up with higher utility bills, more wear on equipment, and increased maintenance over time.
The Energy Cost Reality
Pool pumps are typically the second largest energy user in homes, consuming 1,500-2,500 watts and costing homeowners $30-150 per month to operate. During swimming season, they account for 20-30% of total electricity bills.
Here’s where smart equipment selection pays off:
Variable speed pool pumps can reduce energy consumption by 50-80% compared to traditional single-speed pumps. Reducing pump speed by just 50% decreases energy consumption by approximately 87% due to pump affinity laws.
A variable speed pump could save you up to 90% on energy costs compared to conventional single- or two-speed pumps. Most systems pay for themselves within 2 years or less.
By carefully designing the plumbing and equipment layout from the start, you ensure the pool is both comfortable to use and cost-effective to operate for the next decade or more—even though you wouldn’t notice these details during construction.
Pebble Finishes: Where Durability Meets Design
The pebble finish is the interior coating that defines your pool’s character. It’s what you’ll see and feel every time you use the pool.
Beyond color and texture, you need to understand how the pebble finish bonds to the underlying shell and how it reacts to water chemistry and sunlight over time.
Application Technique Matters
The application technique—how evenly it’s troweled, how thickly it’s applied, and how well it’s cured—directly impacts durability, smoothness underfoot, and resistance to scaling or staining.
Even a beautiful color can fade or develop rough spots if the finish isn’t properly installed. This is why Century Pools guides homeowners to consider both the material and the workmanship.
The goal is a pool that not only looks great but also feels comfortable, is easy to maintain, and holds up beautifully for years. Gunite pools generally need to be resurfaced every 7 to 10 years to maintain their appearance and structural integrity, making the quality of the initial finish application critical.
Custom Features: From Functional to Memorable
Features like cabo shelves, water elements, and integrated seating transform functional pools into family gathering spaces.
But the real value comes from thoughtful placement based on how you’ll actually use the pool.
A Feature That Changed Everything
Consider a family who originally wanted a standard shallow step entry. After discussing how the kids and adults would use the pool, Century Pools suggested a cabo shelf along one side with integrated seating and room for play.
At first, the family wasn’t sure it would fit their vision. But once installed, the shelf became the hub for everything—the kids could safely play, adults could relax nearby, and entertaining became easier with built-in seating near the pool bar area.
That one adjustment transformed the pool from a visually appealing backyard feature into a space the whole family uses every day. It shows how thoughtful placement of functional features can completely redefine the experience.
Reminder: A cabo shelf is a long, elongated step with shallow depth that can sometimes be made to accommodate chairs or lounging.
Timeline and Quality Checkpoints
Gunite pool construction typically takes three to six months to complete from start to finish for the active construction period. This doesn’t include the curing period, which is essential to the concrete’s natural structural strength.
What to Expect at Each Stage
Week 1-2: Site evaluation and design finalization
This is when soil conditions, drainage, and structural requirements are confirmed. Changes are easy and inexpensive at this stage.
Week 2-3: Excavation and site preparation
Watch for strategic hand-shaping of pool sides and attention to weak soil areas. The excavation should match the engineered plans exactly.
Week 3-4: Steel reinforcement installation
Check that rebar spacing matches specifications and that all bars are properly tied together. The steel should be positioned away from the dirt walls.
Week 4-5: Gunite application
Look for methodical application, uniform coverage, and proper encapsulation of all rebar. The crew should not rush this critical phase.
Week 5-9: Curing period
The gunite needs 28-30 days to cure properly. Proper water-curing during this period is essential for long-term strength.
Week 9-11: Plumbing and equipment installation
Verify that pipe sizing matches specifications and that equipment is appropriately sized for your pool volume and usage patterns.
Week 11-13: Pebble finish application
Watch for even troweling, consistent thickness, and proper curing procedures. The finish should be smooth and uniform.
Week 13-16: Decking, coping, and final details
The surrounding hardscape should integrate seamlessly with the pool and your existing landscape.
Recognizing Meticulous Craftsmanship
You don’t need to be a pool expert to recognize quality work. Watch for these indicators throughout construction:
- Crews work systematically, not frantically
- Measurements are checked multiple times before proceeding
- Problems are addressed immediately, not covered up
- The site is kept organized and clean throughout construction
- Questions are answered thoroughly with technical explanations
- Timelines account for proper curing and aren’t artificially compressed
- Materials match specifications exactly
Rushed work shows up years later as cracks, leaks, equipment failures, and high operating costs. Meticulous work creates pools that families cherish for generations.
Building More Than a Pool
Century Pools knows backyard pools are more than a luxury. These are the treasured meeting places where memories are made, family events are held, and new beginnings are celebrated.
That’s why the company carefully injects personalized experience into every customer pool, guided by six decades of multigenerational expertise passed down from founder Brian O’Neal to his three sons and now to second-generation family members.
Being a multigenerational pool contractor isn’t just about longevity—it’s about building lasting relationships based on trust and shared dreams.
Each project is an opportunity to demonstrate commitment to excellence and to earning your trust. The O’Neal family is honored to continue their legacy by creating spaces that families cherish for generations.
When you understand what happens below the surface—both literally in terms of construction and figuratively in terms of planning and expertise—you can make informed decisions about one of the most significant investments in your home.
Your pool will be part of your family’s story for decades. Make sure it’s built by people who understand that responsibility.
