5 things you must know before building a swimming pool
From soil testing to safety codes — what actually determines whether your pool lasts 5 years or 50.
Building a swimming pool is one of the biggest investments you’ll make in your property — and one of the most permanent. Unlike a renovation you can redo in a few years, a pool is buried in the ground, tied into your plumbing and electrical systems, and expected to last decades. Get the fundamentals wrong, and you’re not looking at a quick fix — you’re looking at cracked shells, chronic leaks, or a pool that never quite runs the way you imagined.
Your soil and site conditions decide the entire design
Most people think pool design starts with shape and size. It actually starts underground.
Soil type
Expansive clay soils swell when wet and shrink when dry, putting uneven pressure on a pool shell year-round. Loose or sandy soils may need deeper footings to prevent settling. Rocky terrain changes excavation cost and timeline significantly.
Water table depth
If groundwater sits close to the surface, an empty pool can be pushed upward by hydrostatic pressure — a real phenomenon called “pool popping.” High water table sites need hydrostatic relief valves and a properly engineered base.
Slope and drainage
Surface water needs to drain away from the pool structure and deck, not toward it. Poor grading pools rainwater against the shell, accelerating erosion and increasing pressure over time.
Skipping a geotechnical assessment to save time is the most expensive shortcut in pool construction. Structural repairs to a cracked or shifted shell often cost more than the original excavation and structural work combined.
Not all construction types are equal — match the method to your needs
There’s no universally “best” option — only the best option for your budget, timeline, and design goals.
Gunite / shotcrete (RCC)
- Fully customizable shape and features
- Extremely durable, long lifespan
- Highest cost
- 6–10+ week build time
Vinyl-lined
- Lower upfront cost
- Faster installation
- Liner needs replacing every 7–10 years
- Less puncture resistant
Fiberglass shell
- Installed in days, not weeks
- Low long-term maintenance
- Limited to pre-set shapes
- Site access constraints
What determines the right fit
- Total budget vs. lifetime cost
- Desired shape and custom features
- Timeline flexibility
- Long-term maintenance appetite
Filtration and plumbing design is where pools succeed or fail long-term
A pool can look stunning on handover day and still become a maintenance nightmare within months if the system underneath wasn’t sized correctly.
- Turnover rate: the entire pool volume should pass through the filter every 6–8 hours for residential pools, faster for commercial ones.
- Correct pump sizing: undersized pumps cause cloudy water and algae; oversized ones waste energy and erode fittings.
- Circulation layout: skimmers, drains, and return jets must be placed to avoid stagnant “dead zones.”
- Filter type: sand, cartridge, or DE — chosen based on bather load, water quality, and how hands-on you want maintenance to be.
Structural problems are visible and get fixed. Filtration problems are invisible until the water turns green — and by then, the fix usually means re-engineering plumbing that’s already buried under the deck.
Waterproofing and expansion joints prevent the #1 long-term complaint: leaks
Even a perfectly engineered shell will develop cracks over time if these two details are skipped.
Waterproofing membranes
Must be applied correctly at every junction — floor-to-wall, plumbing penetrations, and the pool-deck interface. A rushed membrane is the biggest cause of slow, hard-to-diagnose leaks that surface 1–2 years after handover.
Expansion joints
Gaps built into the deck and shell to absorb temperature and ground movement. Without them, concrete has nowhere to move except into itself — resulting in cracks straight through the structure.
Waterproofing and expansion joints don’t show up in a “finished” photo. That makes it easy to cut corners here without the client noticing — until the damage is already done.
Compliance and safety codes aren’t optional extras
A pool isn’t just a design and engineering project — it’s a legal one too.
- Barriers and fencing: to prevent unsupervised access, especially with children present.
- Anti-entrapment drain covers: anti-vortex covers are now standard for safety and code compliance.
- Electrical bonding and grounding: required for all pumps, lights, and equipment near water.
- Setback distances: from property lines, septic systems, and underground utilities — varies by local authority.
Beyond safety, non-compliant construction can create legal and insurance complications, and in some jurisdictions can block final approval or occupancy sign-off entirely.
Build it right, the first time
A great pool isn’t just about the finish you see on day one — it’s the decisions made below the surface. At Layers Pools, every project starts with these fundamentals.
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