Building a Pool? Here’s What the Pros Don’t Always Tell You

I’ve been in the pool building game for a long time—long enough to have seen it all. I’ve watched projects come together like a symphony, right on schedule and budget. And, I’ve been the guy called in to fix the messes when things go sideways. To be honest, the difference almost always boils down to one thing: understanding what’s actually happening.

A pool isn’t just a pretty hole in the ground you fill with water. It’s a complex system that has to live in harmony with your house, your land, and the local environment. It’s a serious structural and mechanical project. The dream of a backyard oasis is exciting, but turning that dream into a reality that lasts for decades takes a bit of knowledge.

My goal here isn’t to sell you anything. It’s to pull back the curtain and show you the real process, from the dirt up. This is the stuff I teach my own crew—the foundation for a project that brings you joy, not a money pit full of headaches.

First Things First: It All Starts with the Ground

Before anyone even sketches a design, the first thing a real pro worries about is the ground your pool will sit in. Seriously. The earth is the most critical construction material you’ve got, and ignoring it is probably the single most expensive mistake you can make. A pool shell is basically a boat. When it’s empty, groundwater can literally float it right out of the ground. When it’s full, it’s holding back thousands of pounds of soil pressure.

Getting to Know Your Dirt

We always start with a soil analysis, usually handled by a geotechnical engineer. In many places, this isn’t even optional. The engineer takes core samples to figure out what we’re working with. Is it nice, stable sandy loam? Or is it expansive clay, which is a total nightmare?

Expansive clay swells up when it gets wet and shrinks when it dries. I once saw a gorgeous new pool with a crack you could stick your hand in. The builder just skipped the soil report, and the shifting clay snapped the concrete shell like a cracker. A good geotechnical report will probably cost you between $500 and $2,500, depending on where you are. Let me tell you, it’s the cheapest insurance policy you’ll ever buy for your pool.

Another big one is the water table. If you’re in a low-lying or coastal area, the ground might be saturated just a few feet down. This creates a huge amount of upward pressure on the bottom of the pool. To handle this, we install a hydrostatic relief valve in the main drain. It’s a simple little one-way valve that lets groundwater in if the pressure gets too high, saving the pool from popping up. It’s a tiny part that prevents a total disaster.

The Nitty-Gritty: Building a Bulletproof Pool Shell

With the engineering figured out, the real work begins. This is where experience and technique are everything. Every single step builds on the last, and a shortcut early on will haunt you later.

The Big Dig and the Steel Skeleton

First, we dig the hole with an excavator. This has to be done with precision to match the pool’s shape, leaving just enough room for the plumbing and the thick concrete shell. Over-digging is just a waste of money on extra concrete. After the dig, a steel crew comes in to build the rebar cage. They bend and tie ribbed steel bars by hand, creating the skeleton that gives the concrete its real strength. A structural engineer provides the blueprint for this, and following it to the letter is non-negotiable.

The Pool’s Circulatory System: Plumbing

Before a drop of concrete is sprayed, we lay all the pipes. This includes the main drains, skimmers, and return lines. Here’s a pro tip: a quality builder will use thick-walled, 2-inch (or larger) PVC pipe. Some guys try to save a few bucks by using 1.5-inch pipe, but that chokes the whole system. That seemingly small decision can cost you an extra $30 to $60 a month in electricity, adding up to thousands over the pool’s life.

And here’s the most important part: after the pipes are in, we pressure test them. We cap the lines and fill them with air or water to a set pressure for a full 24 hours. If that pressure drops, there’s a leak. We find it and fix it before it’s buried in concrete forever. I learned that lesson the hard way once. We had to jackhammer a brand-new deck to fix a leaky joint we missed. Never again.

The Main Event: Gunite and Curing

Gunite day is the most dramatic day of the build. A skilled crew sprays a concrete mix at high velocity over the rebar cage, building up the walls and floor. It’s loud, messy, and pretty incredible to watch.

But then comes the most overlooked step: curing. Concrete doesn’t just dry; it hardens through a chemical reaction that needs water. For the first week or two, you, the homeowner, will need to spray the shell with a garden hose a few times a day. This prevents it from drying too fast, which causes cracks and weakness. A patient, well-cured shell is the key to a pool that lasts a lifetime.

So, How Long Does This All Take?

People always want to know the timeline. For a custom concrete pool, you’re generally looking at 8 to 12 weeks from the day they start digging, but it can vary. Here’s a rough idea of how the chaos unfolds:

• Week 1-2: Final planning, getting permits, and marking the layout in your yard.
• Week 3: The main event! Excavation, forming the shape, and laying the first runs of plumbing.
• Week 4: The steel crew builds the rebar skeleton, and all the plumbing is finalized and pressure tested.
• Week 5: Gunite day! The concrete shell is shot and shaped. Then the curing process begins.
• Week 6-7: While the shell cures, work can start on the tile and coping (the edge of the pool).
• Week 8-9: The deck is formed and poured. Any electrical work and equipment installation happens now.
• Week 10-12: The interior finish (like plaster or pebble) is applied, the pool is filled with water, and the system is fired up and balanced. Then, finally, it’s time to swim!

Let’s Talk Money: The Three Main Types of In-Ground Pools

Your choice of pool type really comes down to your budget, your yard, and how custom you want to get. There’s no single “best” option, just the best option for you.

Concrete (Gunite/Shotcrete): This is the top-tier, most durable option. You get total freedom with the shape, size, and features like tanning ledges or vanishing edges. The downside? It’s the most expensive and takes the longest to build. For a standard 15×30 foot pool, you can expect a concrete build to start around $60,000 and go way, way up from there depending on features. The interior surface will also need to be redone every 10 to 20 years.

Fiberglass: These are pre-made shells that get delivered on a truck and craned into the hole. Installation is super fast—sometimes just a few days. The surface is smooth and resists algae, which is a nice perk. The catch is that you’re limited to the shapes and sizes the factory offers. On a 15×30 foot pool, fiberglass often falls in the $45,000 to $70,000 range. Oh, and you need good access to your backyard for that crane!

Vinyl Liner: This is the most budget-friendly way to get an in-ground pool. You get a steel or polymer wall structure with a custom-fitted vinyl liner stretched inside. They feel smooth and come in lots of patterns. The main trade-off is durability; a liner can be punctured and will need to be replaced every 7 to 10 years on average. A 15×30 vinyl pool typically starts in the $35,000 to $50,000 range.

The Brains of the Operation: The Equipment Pad

The pump, filter, and heater are the heart, lungs, and muscle of your pool. The choices you make here will directly affect your monthly bills and how much time you spend on maintenance.

Let’s talk pumps. These days, a variable-speed pump (VSP) is a no-brainer. Yes, it might cost $800 or so more upfront than an old-school single-speed pump, but it can save you up to $400 a year on your electric bill. It literally pays for itself in a couple of seasons by running at a super-low, energy-sipping speed most of the day.

For sanitizing, salt chlorine generators are incredibly popular. They use a small amount of salt in the water to create their own chlorine, so you don’t have to handle harsh chemicals. The water feels softer, too. A salt system might add $1,500 to $2,500 to the initial build, but you’ll save on buying chlorine tabs every week.

How to Hire a Good Builder (and Avoid a Disaster)

Finding the right builder is the most important decision you’ll make. A great one makes the process smooth; a bad one can turn your dream into a legal and financial nightmare.

Before you even call a builder, do this quick checklist:

• Know Your Space: Find your property survey to see where utility lines and easements are.
• Have a Wishlist: Separate your ‘must-haves’ (like a safety cover) from your ‘nice-to-haves’ (like that waterfall).
• Set a Realistic Budget: Know your all-in number, including landscaping and furniture.
• Take Photos: Snap pictures of your backyard and, crucially, the access path for machinery.

When you interview potential builders, here are three questions you MUST ask:

1. “Are you licensed and insured for pool construction specifically? Can I see the documents?” Don’t just take their word for it.
2. “Can I speak to your last three clients?” Not their best three, their last three. This gives you a real, unfiltered look at their recent work and process.
3. “Who is my point of contact, and how often will I hear from them?” Good communication is the key to a low-stress project.

Heads up! A major red flag is a builder who asks for a huge percentage of the total cost upfront (more than 10-15% is often a warning sign) or who gives you a vague, one-page contract. A proper contract is detailed and spells everything out.

The Most Important Part: Safety is Not Optional

Okay, this is the part we have to get serious about. A pool comes with huge responsibilities. Your local laws will be very strict about fencing. Expect to need a non-climbable fence that’s at least 4 to 5 feet high, with self-closing, self-latching gates.

Another invisible but life-saving feature is electrical bonding. This is where an electrician connects all the metal parts of the pool—rebar, ladders, lights—with a copper wire. It prevents dangerous electrical currents from forming in the water. It absolutely must be done by a licensed electrician who knows pools.

And finally, drain safety. A crucial federal safety law was passed to prevent suction entrapment at the main drain. All modern pools are built with anti-entrapment drain covers or multiple drains to eliminate this risk. If you ever see a pool with a single, old-fashioned flat drain cover, do not use it.

Disclaimer: Look, this guide is based on my professional experience and common industry building codes. But every single project is unique. Your local codes, soil, and backyard will have the final say. Always, and I mean always, work with licensed and insured local professionals. Check their references, see their work, and make sure you have a solid contract before a single shovel hits the dirt.