An infinity pool’s seamless edge isn’t an illusion created by clever angles — it’s precise hydraulic engineering, with a wall built a fraction of an inch lower than the rest of the pool so water spills continuously into a hidden basin below. Getting that effect right depends on more than construction quality: it depends on having the right view, the right site conditions, and a structure engineered to handle a continuously moving body of water. This guide covers how it actually works, the design choices involved, and the property requirements that determine whether an infinity edge is realistic for your lot.
How an Infinity Pool Actually Works
| Component | What It Does |
| Weir wall | The “vanishing” edge — built 1/16″ to 1/4″ lower than the rest of the pool, precise enough for water to spill over evenly in a thin, glass-like sheet |
| Catch basin (surge tank) | A hidden trough below the weir, typically 12–24 inches deep and 12–18 inches wide, that collects overflow and absorbs the surge of water displaced when swimmers enter the pool |
| Recirculation system | High-volume pumps pull water continuously from the catch basin, filter it, and return it to the main pool in a closed loop |
The weir’s precision is what makes the edge work — even a slight unevenness shows up as visible high or low spots in the water sheet instead of a clean, level line. That same continuous water movement across the surface is also why infinity pools tend to skim debris, oils, and dust more effectively than a standard pool with a fixed skimmer.
Benefits of an Infinity Edge
- A genuinely dramatic visual effect. The pool appears to merge with whatever lies beyond it — ocean, valley, skyline, or simply your own landscaped yard — in a way no other pool design achieves.
- Better water clarity. The continuous surface overflow pulls floating debris and oils off the water more effectively than standard skimming, a functional benefit beyond the visual one.
- Makes your property’s best view a permanent design feature, rather than something you only appreciate from a window or a single vantage point.
- A distinctive architectural statement. At the luxury end of the market, a well-executed infinity edge is one of the more memorable features a property can have — though, like any pool, it’s a lifestyle and design investment first, not a guaranteed dollar-for-dollar return at resale.
Edge Design Options
Wet Edge vs. Dry Edge
- Wet edge: the catch basin is designed to always hold visible water while the system runs, creating a reflecting pool below the vanishing edge. This is the more dramatic option and the more common choice in luxury builds.
- Dry edge: the catch basin is designed to stay hidden from view, integrated into the surrounding landscaping rather than visible from the house or main pool deck. Cleaner architecturally, but it requires more careful landscape design to conceal successfully.
Edge Length and Placement
An infinity edge doesn’t have to run the full perimeter of the pool — in fact, most don’t. A single edge facing your best view is the most common and most cost-effective approach. Corner or two-edge designs are also achievable for properties with a wraparound view, at a higher cost given the added weir length and catch basin complexity. (A related but distinct concept worth knowing: a deck-level or “mirror” pool keeps the waterline flush with the surrounding terrace for a calm, reflective surface, rather than spilling over a vanishing edge — a different visual effect aimed at a different result.)
Material Choice
- Concrete is used in roughly 90–95% of infinity pools, and for good reason: the weir must stay level within fractions of an inch under constant water pressure, and pouring the catch basin and main shell as a single structure avoids the settling issues that could throw off that precision over time. Concrete also allows any edge length or shape. See Concrete Pools for the full design range.
- Fibreglass infinity-ready shells exist, but represent a small share of builds, limited by the same roughly 16-foot transport width that caps fibreglass shells generally — see Cost to Install a Fibreglass Pool for why that limit exists. Fibreglass infinity edges tend to suit flatter lots where installation speed matters more than full design freedom.
- Vinyl infinity-edge construction is possible and has a long track record, though it’s the least common of the three — the liner is gasketed to the top of the spillway wall, with the catch basin built as a separate connected structure.
Views: What Makes (or Breaks) an Infinity Pool
The view is just as important as the engineering, and it’s the part that’s easiest to get wrong:
- An infinity edge facing a fence, a neighbour’s wall, or a blank lot line defeats the entire purpose. Before committing to the feature, confirm the sightline actually leads somewhere worth looking at.
- You don’t need an oceanfront or clifftop property. A modest elevation change combined with the right orientation — facing a treeline, a ravine, a golf course, or simply an open stretch of your own landscaped yard — can be enough to create a genuine sense of the pool merging into the view beyond it.
- Think about permanence, not just the current view. A neighbouring lot that could be developed, or trees on an adjacent property that will eventually grow tall enough to block the sightline, are both worth considering before investing in a feature this dependent on what’s visible beyond your property line.
- Orient toward your longest, least-obstructed sightline, even if that’s not the most obvious direction from inside the house.
Property Requirements
- Elevation and grading: a natural slope is the ideal starting point, since the edge needs somewhere to visually fall away to. Flat properties can still support an infinity pool using an artificial slope or an elevated structure built into the design, but this adds meaningfully to both budget and construction timeline. See Pool Installation on a Slope for the broader site-grading picture.
- Soil and structural engineering: the site needs to support not just the main pool shell but the catch basin below it, plus the hydrostatic pressure of constantly moving water. A soil report is a standard part of the design process before plans are finalized — this isn’t a feature to design first and engineer later.
- Space beyond the visible edge: the catch basin sits hidden below and slightly beyond the weir, so your landscape or deck design needs to account for that footprint, even though it won’t be visible in the finished result.
- Permits and engineering sign-off: given the structural complexity, infinity pools are more likely to require detailed engineering drawings as part of the permit process. See Pool Permits Toronto for the general requirements.
Costs at a Glance
As an incremental cost, the infinity edge feature itself typically adds $50,000–$250,000 over a comparable standard-edge pool of the same size, depending on edge length, catch basin scope, and finish detail — which is exactly why full infinity pool projects often land in the $150,000–$250,000+ range described in our concrete pool cost guide. If you’re considering an infinity-edge lap pool specifically, see Cost to Install a Lap Pool for that scenario.
Is an Infinity Pool Right for You?
An infinity edge is worth pursuing if you have a genuinely strong view to showcase — whether that’s a dramatic natural landscape or simply a well-designed backyard — and a site that can support the engineering, either naturally or through additional grading. If the view or site conditions aren’t there yet, the same architectural drama is achievable through other premium concrete features; see Concrete Pools for the broader design palette.
Frequently Asked Questions
How does an infinity pool actually work?
A wall (the weir) is built a fraction of an inch lower than the rest of the pool, so water spills continuously over it into a hidden catch basin below, then gets pumped back into the main pool in a closed loop.
Do I need a sloped property for an infinity pool?
A natural slope makes the engineering easier and more cost-effective, but flat properties can still support an infinity edge using an artificial slope or elevated structure — at added cost and complexity.
How much does an infinity edge add to the cost of a pool?
Typically $50,000–$250,000 over a comparable standard-edge pool, depending on edge length and catch basin scope — consistent with why full infinity builds often reach $150,000–$250,000+ in total.
What’s the difference between a wet edge and a dry edge?
A wet edge keeps the catch basin visibly holding water as a reflecting pool below the vanishing edge — more dramatic and more common in luxury builds. A dry edge hides the basin from view, requiring more landscaping to integrate cleanly.
Can a fibreglass or vinyl pool have an infinity edge?
Yes, though both are far less common than concrete. Fibreglass suits flatter lots and faster installs but is limited by standard shell transport width; vinyl infinity construction is possible but the least common of the three approaches.
Get a Site Assessment
Whether an infinity edge is feasible on your property depends on your specific view, slope, and soil conditions.
Contact Easy Pools at (647) 449-9512 for a free, no-obligation site assessment for your infinity pool project.