Resort & hotel pools
Resort and hotel pool leak detection
A vessel big enough that evaporation and bather load swamp the reading, and an autofill covering it up.
Why the usual test fails here
On a large vessel, the numbers lie to you
A backyard pool can be settled with a bucket. A resort pool cannot, because everything competing with the leak got bigger. A large surface evaporates a great deal in a Phoenix summer. A busy deck carries water off in towels and swimsuits all day. A slide throws water into the air. Splash-out lands on a deck draining somewhere other than the pool. And an autofill replaces the lot without anyone seeing a level drop.
All of that is real water leaving the vessel and none of it is a leak, so the first job on a commercial pool is arithmetic rather than detection.
What replaces the bucket
- Turn the features and the slide off, and write down that you did.
- Record the make-up meter across a period open to bathers and a period closed to them — that pair separates guests from plumbing.
- Measure against a fixed mark on the tile, not the skimmer throat or gutter lip.
- Measure with the circulation on, then with it off: a bigger loss with the pumps running points at pressure-side plumbing, an equal loss either way at the shell, fittings, main drain or gutter.
- Keep an evaporation reference on the same deck, for the same hours.
Bather load is a season, not a number
A Saturday in July and a Tuesday in February are two different pools, so a busy weekend compared with a quiet weekday stops a holiday being mistaken for a structural problem.
Where they actually leak
A commercial pool has more places to lose water
The vessel
Skimmer and gutter throats, light niches and their conduit, the tile line and expansion joints, main drain sumps and hydrostatic plugs, and the transitions at a bench or beach entry — more penetrations than a residential pool has.
The plumbing
Suction and return lines buried under a wide deck, often with long runs to a remote vault. A leak in a buried return can travel a long way under pavers before finding a joint, so the wet paver is not the pipe.
The systems around it
A surge tank and its level controls, deck drains, the autofill valve, and a spa sharing the vault — each reads on the make-up meter like a leaking pool, so they are isolated first.
And sometimes it is not a leak at all
If the loss turns out to be a pump seal or a seeping union in the vault, we will tell you which one; changing it is your pool service company's work. Locating it is the hard part, and that part is ours.
Method
You cannot close the pool in season
The deck is the amenity guests remember, and a health authority has a view about water level. Both shape the test plan.
Everything measurable with the pool open, measured with the pool open
Make-up meter readings, level against a fixed mark, an evaporation reference, a listen around the perimeter.
Test the plumbing at the vault, not at the pool
Where the layout allows, plugging and pressurising from the equipment side keeps the work off the deck.
Take vessel-side work into the quietest window the property has
One section at a time, agreed with the chief engineer; dye testing needs still water, so it belongs there too.
Respect the level the health authority requires
A pool dropped below its skimmers is a closed pool, so the plan states how far down and for how long, agreed beforehand.
Isolate the vessel from the plumbing to split the question
Plugging the returns and main drain separates a shell or fitting loss from a plumbing loss, which decides whether the rest of the job is on the deck or in the ground.
Mark, photograph, and plan the repair around the deck
Many vessel and fitting repairs need no coping lifted or pavers pulled, and that choice should be made from a known location.
On site
The autofill is why nobody noticed
On a residential pool a leak eventually shows as a low water line. On a commercial vessel the autofill keeps the level perfect and the loss appears only as make-up water — which nobody studies in July, because July is supposed to be high.
So the make-up meter, read across a closed period and an open one, is the most valuable number on the property.
Reporting upward
The engineer and the GM need different things from one page
The chief engineer wants the isolation record: what was plugged, what was pressurised, what held, at what reading. The general manager wants one paragraph saying what happened and how much of the deck is affected, for how long. One document does both.
Scope, plainly: pool and spa vessels and their plumbing, the irrigation, slab and buried supply lines, and the site's service line. Not sewer, drains, gas, water heaters or backflow assemblies.
The work behind a large-vessel locate
Where we work
Resort corridors we work
Old Town, north Scottsdale, Paradise Valley, the Camelback corridor.
Straight answers
What chief engineers and general managers ask
Our autofill runs almost constantly in July. Does that mean we have a leak?
Not on its own. A large vessel in a Phoenix summer loses a great deal to evaporation; the way to settle it is to record the make-up meter across a period closed to bathers and compare it with a period open to them, features off.
Can you test while the pool is open to guests?
Most of it. Meter readings, level measurement, perimeter listening and testing the plumbing from the vault all happen with the pool in use; the parts needing still water go into the quietest window you have.
The loss only shows when the pumps are running. What does that tell you?
It points at the pressure side of the plumbing rather than the shell — returns, buried runs under the deck, the lines out to the vault. If the loss is the same with the circulation off, attention moves to the vessel itself: throats, light niches, main drains, tile line and expansion joints.
Send us the make-up meter reading and a photo of the deck
A photo of the vault, the make-up meter or the wet paver, plus whether the features were running, is enough to start.