When investing in an inground swimming pool, the decision between fiberglass and concrete (gunite) is one of the most critical choices you will make. While both pool types offer a beautiful addition to your backyard, their financial footprints differ dramatically over time. Homeowners often focus solely on the initial purchase price, but the true cost of ownership is determined over the long run. In this guide, we break down the upfront installation and 10-year maintenance costs of both materials to help you make an informed investment.
Upfront Installation Cost Breakdown
The initial cost to install an inground pool depends on the size, accessibility of your yard, and custom features. However, the raw materials and labor requirements for fiberglass and concrete create different pricing structures from day one.
Concrete (Gunite) Pools
Concrete pools are built from scratch in your backyard. After excavation, a steel rebar cage is constructed, and a concrete mixture (gunite or shotcrete) is sprayed onto the frame. Once cured, the surface is plastered and tiled.
- Upfront Cost Range: $55,000 to $100,000+ (for standard sizes).
- Why It Costs More Upfront: Concrete construction is highly labor-intensive and requires specialized trade crews. The build process typically takes 3 to 6 months, during which heavy machinery operates in your yard. The customization options are infinite, but every custom curve and depth increases the price.
Fiberglass Pools
Fiberglass pools are manufactured off-site in a controlled factory environment. The pool shell is delivered to your home as a single, pre-formed piece and set into the excavated hole.
- Upfront Cost Range: $45,000 to $85,000.
- Why It Costs Less Upfront: The installation process is exceptionally fast, often taking only 2 to 4 weeks. Because the shell is already built, on-site labor is significantly reduced, which translates to lower installation costs. However, you are limited to the pre-designed shapes and sizes offered by the manufacturer.
While choosing between fiberglass and concrete establishes your baseline structural budget, the excavation phase itself often introduces unforeseen variables. Homeowners can avoid budgeting shortfalls by studying our guide on the hidden costs of installing an inground pool to prepare for site-specific expenses. Knowing these factors early prevents construction delays and ensures a smoother backyard installation.
10-Year Maintenance & Resurfacing Costs
The real divergence in cost happens after the pool is filled with water. The physical properties of fiberglass and concrete affect how much you will spend on chemicals, electricity, and structural repairs.
Algae Resistance and Chemical Usage
Concrete is highly porous. Its rough surface provides micro-crevices where black and green algae can easily attach and grow. To keep a concrete pool clean, you must run your filtration system longer and use more sanitizing chemicals (such as chlorine and algaecides).
In contrast, fiberglass shells are finished with a smooth, non-porous gelcoat. Algae cannot easily grip this surface, meaning you use up to 30% fewer chemicals and consume less electricity because your pump doesn’t need to run as long.
Resurfacing and Structural Restorations
This is the single largest long-term cost factor:
- Concrete Resurfacing: Every 7 to 10 years, the plaster surface of a concrete pool degrades due to chemical exposure and wear. The pool must be drained, prepped, and replastered.
- *Average Plaster Cost:* $8,000 to $15,000.
- *Acid Washing:* To remove deep stains between replastering, concrete pools require acid washes every 3 to 5 years ($800 – $1,500).
- Fiberglass Gelcoat Durability: A high-quality fiberglass gelcoat can easily last 25+ years without needing to be resurfaced, provided the pool chemistry is maintained. There are no plaster degradation issues or regular resurfacing requirements.
Which Pool Material Has the Best ROI?
To illustrate the total cost of ownership, let us look at a conservative 10-year projection for a standard 15×30 foot pool:
| Expense Category | Concrete Pool (10 Years) | Fiberglass Pool (10 Years) |
|---|---|---|
| **Initial Installation** | $75,000 | $65,000 |
| **Chemicals & Water Treatment** | $8,000 | $3,500 |
| **Electricity (Pump & Filter)** | $5,000 | $3,000 |
| **Replastering / Gelcoat Maintenance** | $10,000 (1 replaster) | $0 |
| **Acid Washing & Cleaning Labor** | $2,500 | $500 |
| **Total 10-Year Investment** | **$100,500** | **$72,000** |
The Verdict
While concrete pools offer unparalleled design flexibility and size customization, they demand continuous maintenance and high recurring costs. If you want a pool that you can customize to fit any backyard shape and are prepared for long-term upkeep, concrete is the choice. However, if your goal is to minimize lifetime expenses, reduce daily maintenance chores, and get swimming in weeks rather than months, a fiberglass pool is the clear winner for return on investment.