Leak Detection in San Antonio & Bexar County
Armor Pro Services finds hidden water leaks across San Antonio and Bexar County before anyone cuts concrete or digs a trench. If your SAWS bill jumped, a warm patch sits on the tile, or you hear water running with every fixture off, leak detection is the diagnostic that comes first: we isolate the system at the meter, prove whether water is escaping on the supply side or the drain side, then pinpoint the exact spot within inches. Licensed under Texas RMP #36282, with a written diagnosis before any repair quote.
Leak Detection: What We Actually Do Before We Cut Anything
Leak detection runs the same honest order every time, and the first step is never a saw. We start at the water meter. Shut every fixture, and if the small leak-indicator dial keeps creeping, water is escaping somewhere in the pressurized system. That one test tells us whether you have an active supply leak at all before we bring out any equipment. From there we isolate the system to prove it's a pressurized supply leak and not a drain problem, because the two look identical from the living room and get fixed nothing alike.
Why the meter test comes first: a slab or yard supply leak runs 24 hours a day, so even a small one shows up on a SAWS bill fast. The meter test is free and takes two minutes before we ever arrive.
Once we know which side is leaking, we pinpoint the exact spot. For a pressurized supply leak we use acoustic listening discs that pick up the hiss of water escaping under pressure, plus pressure isolation to narrow which line is failing. For a drain-side or sewer leak we camera the line and mark the defect with a 512Hz sonde so the locator reads the exact spot and depth through the slab or soil. We find it, we show you where it is, and then we talk about the fix. Tell us what you're seeing and we'll come back with a plan.
Slab Leak Detection on a Post-Tension Slab
Most homes south of Loop 1604 were built after 1970 on post-tension slab foundations, which is why slab leak detection is a recurring call in San Antonio and not a freak event. On a post-tension slab, precision matters more than usual, because there are tensioning cables cast into the concrete that must not be nicked. We isolate the system, confirm it's a supply leak, then pinpoint with acoustic discs good to within a few inches, so any opening stays small and clear of the cables.
Pinpoint before you cut: we locate the leak and show you where it is on the floor before we quote a single thing. A smaller, confirmed opening means a cleaner repair and far less floor to patch back.
A warm spot on the tile usually means the leak is on the hot-water side. A cold-line pinhole won't warm the floor at all, and that's the clue homeowners rule out by mistake. Once we've pinpointed it, the repair is its own decision, and we walk through how we repair or reroute a confirmed slab leak in San Antonio homes once detection is done. For the full picture of slab leak repair options, spot repair versus reroute, that page lays out each path and prices them upfront.
The Pre-1970 Trap: When It's a Drain Leak, Not a Supply Leak
This is the section most leak pages leave out, and it's where a lot of San Antonio homeowners get a wrong repair. In the pre-1970 core, Monte Vista, Olmos Park, and much of the West and South Side, what gets called a slab leak is often not a pressurized supply line at all. It's a cracked cast-iron or Orangeburg drain lateral running under the slab, cracked at a joint or crushed by decades of pecan-root pressure and expansive-clay movement. The tell is completely different, and knowing it keeps you from cutting concrete on a hunch.
- A supply leak runs constantly and spins the meter with everything off.
- A drain-side under-slab failure shows up only when you use water: a slow floor drain, sewer smell, or damp flooring near a bathroom that dries out between uses, with the meter sitting still.
Those two get found nothing alike. A drain lateral is a camera-and-512Hz-sonde job, not a listening-disc job, which ties straight into our under-slab drain and sewer line diagnostics. We camera the line, mark the defect with the sonde, and read the exact location and depth before anyone opens the slab. Ask what the meter is doing first, and you find the real problem instead of the one that was easy to guess.
Yard Leaks and Hidden Pressure-Loss Pinpointing
Not every hidden leak is under the house. A soggy stripe of grass that stays green in a drought, a hissing water meter, a sinkhole-soft patch in the lawn, or pressure that drops across the whole house can all mean the service line between the SAWS meter and the home is leaking underground. We locate yard-side and service-line leaks the same disciplined way: isolate the line, confirm the loss is on the pressurized side, then pinpoint with acoustic correlation and line tracing so we dig one hole in the right place instead of trenching the whole yard.
Why pressure matters here: high incoming pressure wears pipe out faster and masks small losses. When we find a leak we also check the pressure-reducing valve at the main, because a home running well above the recommended range is setting up the next leak.
In Helotes and the NW Bexar Hill Country, many properties run on private wells with incoming pressure at 90-plus psi, and that elevated pressure both accelerates pinhole failures and makes a small yard leak harder to feel at the fixtures. A precise pinpoint there saves a lot of digging. Ready when you are: call 210-212-7667.
Leak Detection Across Schertz, Converse, Alamo Heights, and Helotes
We run leak detection across the whole five-city service area, and each corner of it leaks a little differently.
- In Schertz, the builder subdivisions off the Guadalupe and Comal county line sit on post-1970 post-tension slab, so Schertz leak detection is usually a pinholed copper supply line we pinpoint with acoustic listening clear of the tensioning cables.
- In Converse, the FM 1976 corridor splits between aging clay-lateral homes where it's a drain-side sonde job and 8-to-12-year-old builds toward Live Oak where a failing PRV or expansion tank mimics a leak.
- In Alamo Heights, inside Loop 410, the dense pre-1970 housing stock means cast-iron under-slab laterals are a common find, not copper pinholes.
- In Helotes, high-pressure Hill Country wells push small losses that a careful pressure isolation catches.
Wherever the home is, the method holds: meter test first, prove supply versus drain, then pinpoint with the right tool before we cut. That's how we keep a leak call to one trip and the right hole, across all of Bexar County. If the leak is active and spraying right now, treat it as urgent and call our same-day line.
When Leak Detection Is the Wrong Call
We'd rather lose the appointment than run equipment you don't need, so here's when we tell homeowners to hold off. If your water meter sits perfectly still with every fixture off, you almost certainly don't have an active pressurized leak, and paying for a full detection workup would be a waste. What you're chasing is more likely a fixture leak above the floor, condensation, a drain that only leaks when used, or a grading and drainage issue outside. We'll flag that honestly instead of selling you a service you don't need.
We also won't take on what isn't ours. If a wet floor turns out to be a genuine structural or foundation problem, cracked slab, heaving, sticking doors, that's a foundation specialist's job, not a plumber's, and we'll say so plainly. And once we've pinpointed a leak, we don't automatically escalate the fix. A single first-time pinhole on otherwise-sound copper is a spot repair, not a reason to repipe the house. Here's the order of operations once you call, so you're not guessing:
- You call 210-212-7667 and describe the signs: jumped bill, warm floor, running water, soggy yard. An active spray gets prioritized.
- We start with the meter test and isolate the system to prove supply versus drain, and rule out above-floor and outside causes.
- We pinpoint the exact spot, acoustic listening for supply, camera-and-512Hz-sonde for drains, and show you where it is.
- You get a written diagnosis before any repair quote, and we route a confirmed leak into the right fix. No concrete or trench until you've seen the number.
Frequently asked
How do you find a slab leak without breaking the floor?
We don't open the slab to find the leak. We isolate the system at the meter first to confirm it's a pressurized supply leak and not a drain problem, since the two are repaired differently. Then we pinpoint the exact spot with acoustic listening discs, which pick up the hiss of water escaping under pressure through the concrete, plus pressure isolation to narrow which line is failing. That locates the leak within a few inches before any concrete is cut, so the opening stays small and clear of the tensioning cables in a post-tension slab. On a drain-side under-slab leak we camera the line and mark the defect with a 512Hz sonde instead. Either way, we show you where the leak is before we quote the repair. Call 210-212-7667.
What are the signs of a hidden water leak?
The most reliable sign is a SAWS bill that jumped with no change in how much water you actually use, because a hidden supply leak runs 24 hours a day. Other common clues: a warm or hot spot on the floor, usually tile, which points at the hot-water side; the sound of water running when every faucet, toilet, and appliance is off; water pressure that dropped across the whole house; new cracks in tile or flooring, or a section that feels damp; a musty smell or mold at a baseboard with no source above the floor; and outside, a soggy or unusually green stripe in the yard. The fastest check takes two minutes: shut off every fixture, find your water meter, and watch the small leak-indicator dial. If it keeps creeping with everything off, water is escaping in the pressurized system.
Do you charge for leak detection separate from the repair?
We give you a written, upfront price before any work, and we tell you exactly what's diagnostic and what's repair so there's no surprise on the invoice. Leak detection is a real diagnostic job, isolating the system, confirming supply versus drain, and pinpointing the exact spot with acoustic listening or a 512Hz sonde, and finding the leak in the right place is what keeps the repair small. Once we've pinpointed it and shown you where it is, we quote the repair separately so you can decide. If the detection turns out to be straightforward and rolls right into the fix, we tell you that too. Call 210-212-7667 and describe what you're seeing for a realistic picture.
Is my problem a supply leak or a drain leak?
That distinction decides the whole job, and it's the most common mix-up on older San Antonio homes. A pressurized supply leak runs constantly and spins the water meter even with every fixture off, and often leaves a warm spot on the floor if it's on the hot side. A drain-side failure, common on pre-1970 cast-iron or Orangeburg laterals in Monte Vista, Olmos Park, and the West and South Side, shows up only when you use water: a slow drain, sewer smell, or flooring that gets damp near a bathroom then dries out, with the meter sitting still. We confirm which one it is before touching anything, because a supply leak is a listening-disc job and a drain lateral is a camera-and-sonde job. Call 210-212-7667.
Can you detect a yard or underground service-line leak?
Yes. A soggy stripe of grass that stays green in a drought, a hissing meter, a soft patch in the lawn, or pressure that drops across the whole house can all mean the service line between the SAWS meter and the house is leaking underground. We isolate the line, confirm the loss is on the pressurized side, then pinpoint it with acoustic correlation and line tracing so we dig one hole in the right place instead of trenching the whole yard. In Helotes and the NW Bexar Hill Country, where private wells push 90-plus psi incoming pressure, we also check the PRV, since high pressure both accelerates the leak and masks it at the fixtures. Call 210-212-7667.
Do you repair the leak once you find it, or just locate it?
Both, under the same Texas RMP #36282, and that continuity matters. The plumber who listened to the pipe and watched the meter knows exactly how the line behaves and whether this is a first failure or the start of a pattern, which is what should drive the repair decision. For a confirmed slab leak that's a spot repair, an overhead PEX-A reroute, or a repipe depending on what the detection found. For a drain-side lateral it's a targeted dig or sewer repair. We find it, show you, quote each path upfront, and fix it. We handle the plumbing side only, not foundation or structural work, and we'll say so plainly. Call 210-212-7667.