Arvada, CO · Jefferson County · Half the pool is underground
Inground Pool Leak Detection & Repair in Arvada, CO
Half of an inground pool is invisible: suction lines from skimmers and main drain, pressure lines feeding every return, all of it buried under deck and yard since construction day. When the visible half tests clean, the buried half gets interrogated line by line, and that interrogation is a discipline of its own.
The Buried Circulation Map
Water leaves the pool through skimmer and main-drain suction lines, meets the pump, and returns through pressure lines to the wall fittings, with side loops for cleaners, water features, and spa spillovers where fitted. Each run is an independent suspect with its own path under the deck, and construction-era shortcuts, tight elbows, unsupported spans, thin-wall pipe, become this decade's failure points as soil and freeze cycles work on them.
Deck behavior offers early testimony: a settling deck section, a lifting corner, or efflorescence at expansion joints often sits over a line that has been feeding the soil below. The mature pools around West Woods carry thirty-plus seasons of that soil movement in their plumbing.
Isolation: One Line on Trial at a Time
The method plugs each line at the pool wall and tests it independently under controlled pressure from the equipment pad. A line that holds its pressure is acquitted in minutes. A line that bleeds is guilty, and the rate says how badly. Suction lines get tested with equal care, since their failure mode, drawing air and losing prime, damages equipment while barely moving the water level, the sneakiest presentation in pool work.
Guilty lines then get located along their run: acoustic listening where the escape is loud enough, and a low-pressure tracer charge for the quiet weeps, walked with a detector above the buried path. The verdict is a mark on the deck or turf, sized for a saw-cut or spade opening rather than a demolition.
Shells, By Construction Type
When every line acquits and the loss persists with equipment off, the shell takes the stand. Gunite and shotcrete crack at stress points, bond beams, step corners, around niches, and dye testing in still water maps whether a visible crack actually flows. Vinyl liners fail at seams, at fitting gaskets, and at the invisible pinhole that dye finds by its steady pull. Fiberglass shells, rarer here, flex-crack at returns and steps.
Shell repairs range from injection and plaster patching on concrete to precision liner patches, and the honest boundary gets stated when a liner's overall age, not its newest hole, is the real diagnosis.
Opening the Deck Without Regret
A located break under concrete gets a squared saw-cut opening at the mark, the repair with materials rated for burial and pressure, backfill compacted in lifts, and the patch poured clean. Under turf, the sod-saving discipline applies as it does on any buried line. What the location work buys is proportion: one repair opening instead of a trench, and a deck patch instead of a deck.
Where a line has failed repeatedly along its length, rerouting sometimes beats a third spot repair: a new run above the old one, under the deck edge or through a planned channel. We price that path honestly when the failure map suggests it.
The Freeze Multiplier on Buried Pool Lines
Pool plumbing here lives shallower than domestic service lines, well inside the frost's reach, which makes closing quality the biggest single variable in a pool's plumbing lifespan. Lines left wet crack at their high points and elbows, then leak invisibly under the deck all the following season. If your pool's loss began the spring after a rushed closing, that history practically names the suspect list by itself. Triage-level questions, whether the loss is even real, start with the bucket arithmetic on our pool leak page, and the tracer methods borrowed for quiet lines are detailed under tracer gas detection. Line-by-line testing books at (303) 552-3896.
Inground Pool Questions, Buried Plumbing Edition
Which pool line fails most often?
Skimmer lines lead locally: they sit shallow, run under moving deck sections, and take the worst of freeze exposure at the skimmer throat connection. Returns follow, then cleaner lines with their smaller diameters. Main drains fail least but cost most to reach, which is why they get acquitted or convicted by pressure before anyone considers the floor.
My pump loses prime overnight but the water level barely drops. Leak?
Classic suction-side air leak: the line or a fitting admits air when the pump rests, without leaking much water outward. It is still a failure, it strains the pump daily, and it pressure-tests just like a water leak. That symptom pattern routes the test order straight to the suction lines.
Can you test lines without draining the pool?
Yes, and it is the standard: lines get plugged at the wall fittings and tested full. Draining an inground pool is itself risky in expansive soil, since groundwater and clay pressure can damage an empty shell, so no diagnostic here should ever require it casually.
The deck is sinking near the skimmer. Is that proof of a leak?
It is strong circumstantial evidence, since escaping water washes fines from under slabs and clay swells unevenly around a wet zone. Proof comes from the skimmer line's pressure test, which takes minutes. Treat deck movement near any pool penetration as a scheduling signal.
Put Every Buried Line Under Oath
Isolation testing, acoustic and tracer location, and saw-cut repairs that spare the deck around them.
☎ Call (303) 552-3896