Port St. Lucie Leak Detection Cracks in a gunite pool: which ones leak and what repair costs
Not every crack in a pool leaks, and not every leaking pool has a crack you can see. The useful distinction is whether a crack goes through the gunite shell or lives only in the finish on top of it.
Telling them apart
| What you see | Usually | Does it leak? |
|---|---|---|
| Fine spider-web pattern across a wide area | Crazing or check cracking in the plaster | No |
| Short hairlines around fittings or steps | Finish shrinkage | Usually not |
| A single line running up a wall, wider at one end | Structural crack through the shell | Often |
| A crack continuing from the wall across the floor | Structural, and usually significant | Often |
| A crack with staining or a chalky trail from it | Water has been moving through | Yes |
| Tile popping off along a line | Movement underneath | Investigate |
| Crack that has visibly widened over months | Still moving | Yes, and the cause needs addressing |
The definitive test is dye at the crack with the pump off and the water still. Dye drawn into the crack means water is going that way. That is part of a detection visit and it is the only way to be sure.
Why Treasure Coast pools crack
Soil. Sandy and, in places, organic soils move. Pools are rigid. Over decades that is the main story.
The water table. This is the local one that matters most. A high water table pushing up under an empty or partly empty shell can crack or even float a pool. It is the reason draining a pool here is not a casual decision, and why anyone who tells you to empty your pool to look for a leak should be questioned closely.
Settlement, particularly on fill or where a deck was added later.
Tree roots from the mature landscaping around older pools.
Original construction, which shows up years later: thin gunite in a spot, a poorly placed construction joint, or steel too close to the surface.
Knowing which of these you have matters, because a crack that is still moving will reopen after a repair if the cause is not addressed. Any honest crack quote includes an opinion about the cause.
How structural cracks are repaired
Sealing. For smaller, stable cracks: the crack is opened out, cleaned, and filled with a material that stays flexible and bonds properly. From about $75 per linear foot.
Injection. Epoxy or polyurethane injected into the crack under pressure so it fills the full depth of the shell rather than a surface groove. This is a real structural repair rather than a cosmetic one.
Staples. For cracks that need the shell held together: the gunite is ground out across the crack at intervals, steel staples are set, and the whole thing is patched. Used where movement has to be resisted rather than merely sealed.
Larger structural work runs $700–$1,500 and up depending on length, location, access, and whether the finish has to be patched or resurfaced afterward. The pool crack repair page has the detail and the pricing page publishes every range.
What a repair cannot fix
A cause that is still active. If a tree root, a settling deck, or a water table problem is still working on the shell, the crack will come back. Sealing it is worth doing, and so is being told plainly that it may not be permanent.
A shell that is beyond it. Some pools, usually old ones with multiple structural cracks and delaminating gunite, reach the point where repair stops being the economic answer. That is a hard conversation, and an honest tech has it rather than selling you a series of repairs.
The cosmetic question
If the crack is in the finish and not leaking, you have a choice rather than a problem. It can be left, or it can be dealt with at the next resurfacing, which is usually the sensible timing. Nobody needs to chase plaster crazing.
Where it is worth acting: a cosmetic crack that is getting longer or wider, which suggests something underneath is moving.
Do not empty the pool to look
Worth its own heading on a Treasure Coast site. A high water table can lift or crack an empty shell, and the damage from that is far worse than any leak. If a pool genuinely has to be drained, it needs to be done with the water table considered and with the hydrostatic relief valve in mind.
Leak detection does not require emptying a pool. Pressure testing, dye testing, and electronic location all work with the pool full, which is how it should be done.
What to expect on the call
Photos of the crack, where it runs, whether it continues onto the floor, whether it has changed over time, how old the pool is, and whether there is a wet area or movement in the deck nearby. We cover Port St. Lucie, Fort Pierce, Jensen Beach, Stuart, Palm City, Port Salerno, and St. Lucie West. The cost calculator prices detection plus the crack repair range.
Frequently Asked Questions
Does a crack in my pool mean it is leaking?
Not necessarily. Plenty of cracks are in the plaster or finish only and do not pass through the gunite, and those do not leak. What leaks is a crack that goes through the shell. Dye testing at the crack under still water is how you tell, and it is part of a detection visit.
What is the difference between a structural crack and a surface crack?
Surface crazing and check cracking live in the plaster or finish and are cosmetic. A structural crack goes through the gunite, is usually wider, often runs in a consistent direction, and frequently continues up the wall or across the floor. Structural cracks are the ones that leak and the ones that need real repair.
What does gunite crack repair cost?
From about $75 per linear foot for sealing smaller cracks. Larger structural work, injection or staple repairs, runs $700–$1,500 and up depending on length, location, and what caused it. The cause matters as much as the crack.
Why did my pool crack?
On the Treasure Coast the usual suspects are soil movement on sandy or organic soils, a high water table pushing on an emptied shell, settlement, tree roots, or an original construction issue showing up years later. A crack that is still moving needs the cause addressed, not just the crack sealed.