Hidden leaks go undetected for 6–12 months on average — non-invasive detection, no demolition. Mon–Fri, 9am–5pm.
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Leak Detection in
DC & Maryland
Your water bill went up. You hear running water when nothing's on. There's a damp spot you can't explain. Hidden leaks cause real damage — silently, over months. DC Metro Plumbing locates leaks precisely using non-invasive methods, so you know exactly what's wrong before we open a single wall.
Mon–Fri, 9am–5pm
Licensed DC & MD
Non-invasive detection first
Upfront pricing
Signs you may have a hidden leak
Check these off — if two or more apply, it's time for a professional leak inspection.
- Water bill noticeably higher than usual
- Sound of running water when nothing is on
- Damp or discolored spot on wall or ceiling
- Musty odor with no visible moisture source
- Warm or hot spot on the floor (slab leak)
- Water meter moves when all fixtures are off
Mon–Fri, 9am–5pm · Priority weekday scheduling
The real cost of waiting
That Unexplained Bill Spike — This Is What It Means
Hidden leaks don't look dramatic. They drip silently behind walls, under slabs, and in crawlspaces for months. But they show up on your water bill long before they cause visible damage.
What a hidden leak costs over time
Slow drip (1 drip/second)
$25–$50
per month wasted
Small supply line leak
$80–$200
per month wasted
Slab or concealed pipe leak
$150–$400+
per month + structural damage
Beyond the water bill — undetected leaks cause mold growth, structural damage, and costly remediation. Early detection is the most cost-effective response.
How to check your meter right now
You can confirm whether you have an active water leak in about 10 minutes with your water meter.
The meter test
- Turn off all water-using appliances and fixtures inside and outside your home
- Note the reading on your water meter (especially the small dial or digital display)
- Do not use any water for 15–30 minutes
- Return and check the meter — if it moved, water is flowing somewhere it shouldn't be
If the meter moved with everything off, you likely have an active leak. Call us for a professional inspection.
IMAGE PLACEHOLDER: Close-up of residential water meter showing leak indicator dial — DC area meter, hand pointing to the detection dial
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Types of hidden leaks
Not All Leaks Look the Same — We Find All of Them
Hidden leaks come in several forms. Knowing which type you're dealing with determines the detection method and the repair approach.
Slab Leaks
High priorityA leak in a supply or drain line running beneath the concrete slab foundation. One of the most damaging leak types — prolonged slab leaks erode the foundation, cause floor cracking, and create mold conditions beneath the slab.
- Warm or hot spot on the floor
- Sound of water running under the floor
- Unexplained floor or wall cracking
- Water bill spike with no visible source
Supply Line Leaks
Moderate — catches up fastLeaks in pressurized water supply lines inside walls or under floors. Because supply lines are under pressure, even a small crack loses significant water volume over time.
- Damp or stained drywall with no surface source
- Water meter moving when fixtures are off
- Low pressure in one part of the house
- Bubbling or peeling paint near walls
Wall & Ceiling Leaks
Visible damage but source often hiddenStaining or dampness on walls and ceilings is often visible — but the source is rarely directly above the stain. Water travels along structural members before dripping.
- Yellow or brown water stains on ceiling
- Soft or bulging drywall
- Mold or mildew growth on interior walls
- Paint peeling or bubbling without recent moisture
Pinhole Pipe Leaks
Slow but cumulativeCopper and galvanized pipes develop pinhole leaks from corrosion, high pH water, or mineral buildup over time. Multiple pinhole leaks across an aging system add up quickly on the water bill.
- Gradual, steady water bill increase over months
- Green staining on copper pipe fittings
- Small damp patches that appear and dry repeatedly
- Older home (pre-1985) with original copper plumbing
Toilet & Fixture Leaks
Often overlookedA running toilet can waste 200 gallons per day — completely silently if the flapper leak is small enough. Supply line connections under sinks, loose fill valves, and wax ring failures are the most common fixture leak points.
- Toilet runs intermittently with no flushing
- Water on the floor around toilet base
- Musty smell in bathroom with no visible source
- High bill despite normal water-use habits
Underground Service Line Leaks
High water lossThe main water service line running from the street to your home can develop leaks due to ground movement, age, or root intrusion. These are entirely underground and can waste hundreds of gallons per day before detection.
- Unexplained wet patch in the front yard
- Water pooling at the foundation wall
- Significant bill spike with no interior leak found
- Reduced pressure throughout the entire house
Slab leak detection
Slab Leaks — Common in DC & Maryland Homes
Slab leaks are particularly common in DC and Maryland homes built before 1985, many of which have copper supply lines running through or beneath the concrete slab. Age, soil movement, and high mineral content in local water all contribute to pipe deterioration beneath the slab.
We locate slab leaks using acoustic detection equipment and pressure testing — without jackhammering until we know exactly where to open. Once located, we give you repair options including direct access repair or pipe rerouting.
Warm floor spot
Hot water line leak beneath the slab — often felt underfoot before any other sign appears
Sound of running water
Audible under the floor when all fixtures are off — characteristic of a pressurized supply line leak
Damp or cracked flooring
Moisture migrating up through or around the slab, causing tile to lift or grout to stain
Unexplained bill spike
Water disappearing from the meter with no visible leak — the slab may be absorbing it entirely
IMAGE PLACEHOLDER: Acoustic leak detection equipment in use on concrete floor — DC basement, technician with listening device, no demolition
"Your home doesn't have to be torn apart to find a leak."
A common fear when calling a leak detection service is that the investigation will cause more damage than the leak itself. Our detection methods are non-invasive — we locate the leak before any wall is opened or any floor is cut.
No exploratory wall cutting during the detection phase
Acoustic equipment pinpoints the exact location first
When access is needed for repair, it's minimal and targeted
Upfront quote before any repair work begins
IMAGE PLACEHOLDER: Plumber using moisture meter on drywall — non-invasive diagnostics, no wall damage, DC home setting
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Detection methods we use
How We Find Leaks Without the Guesswork
Different leak types require different detection tools. We use the right method for the situation — starting with the least invasive approach.
Acoustic Listening Equipment
Electronic amplifiers detect the sound of water escaping under pressure — even through concrete slabs and behind finished walls. We listen at multiple points to triangulate the exact location.
Pressure Testing
We isolate sections of the plumbing system and monitor pressure drop to confirm whether a leak is active, and in which part of the system. Pressure testing confirms what acoustic detection locates.
Moisture Meters & Thermal Indicators
Non-destructive moisture readings through drywall and flooring surfaces identify areas of elevated moisture without any cutting. Useful for narrowing down the affected zone before more targeted testing.
Meter Monitoring & Flow Analysis
We can confirm active leakage using your water meter and compare flow rates across isolated sections of the supply system to locate the branch where loss is occurring.
Our process
From Detection to Repair — How It Works
You shouldn't have to guess what happens when you call about a leak. Here's the exact sequence — no surprises at any stage.
1
You Call, We Listen
You describe what you're seeing — bill spike, damp spot, running water sound. We ask targeted questions to narrow the likely leak type before we arrive.
2
On-Site Detection
We arrive with detection equipment and systematically test the system. Non-invasive methods first — acoustic, moisture, pressure — to locate the leak without cutting.
3
Clear Findings Report
We show you exactly what we found — the leak type, location, and our honest assessment of severity. Plain language, no jargon, no pressure.
4
Upfront Repair Quote
You receive a written repair price before we touch anything. We explain the repair options and let you decide. No work starts without your approval.
5
Precise Repair
Access is opened only where needed. Repair is completed by a licensed plumber. We test after repair to confirm the leak is resolved before we leave.
Honest pricing
What Leak Detection Costs in DC & Maryland
Real cost ranges for leak detection and repair in the Washington DC and Maryland market. Your exact written quote is confirmed before any work begins.
Leak detection — standard
$150–$350
Visual inspection, moisture testing, pressure check for supply line or fixture leaks. Most residential calls fall in this range.
- Full walkthrough inspection
- Moisture meter testing
- Pressure diagnostics
- Written findings report
Slab leak detection
$300–$600
Acoustic equipment and extended pressure testing needed for below-slab leaks. Includes precise location marking before any concrete work.
- Acoustic listening equipment
- Pressure isolation testing
- Exact location marking
- Written findings and repair options
Leak repair
$200–$1,800+
Depends on leak type, access difficulty, and pipe material. Simple fixture repairs at the low end. Slab access repairs and pipe rerouting at the high end.
- Targeted access only where needed
- Pipe repair or section replacement
- Pressure test after repair
- Financing available on larger repairs
These are real DC/MD market ranges. Exact written quote provided before work begins. Detection and repair are quoted separately — you decide whether to proceed with repair after receiving the detection findings.
Schedule leak detection
Think You Have a Hidden Leak? Let's Find It.
For priority weekday scheduling, calling is always the fastest route. Submit this form for next-day or scheduled detection — we follow up during business hours.
IMAGE PLACEHOLDER: Plumber explaining leak findings to homeowner — pointing at damp wall stain in DC home, non-invasive equipment visible
Non-invasive detection before any wall is opened
Written findings before any repair quote
Priority weekday scheduling — Mon–Fri, 9am–5pm
Licensed DC & MD — all repair permits handled
Request Leak Detection
For same-week scheduling, call 240-888-9739 Mon–Fri, 9am–5pm. After-hours requests are answered the next business day.
FAQ
Leak Detection Questions DC & Maryland Homeowners Ask
How do I know if I have a hidden water leak?
The most reliable signs are: a water bill that's higher than normal without a change in habits, the sound of running water when everything is off, damp spots on walls or ceilings, musty odors without visible moisture, warm spots on concrete floors, or a water meter that keeps moving when no fixtures are in use. The meter test described on this page can confirm active leakage in minutes.
Does leak detection require opening walls or cutting floors?
Not during the detection phase. We use non-invasive acoustic listening equipment, moisture meters, and pressure testing to locate leaks before any surface is opened. Once the leak is precisely located, any access for repair is minimal and targeted — not exploratory demolition.
What is a slab leak and how is it found?
A slab leak is a water line leak beneath your concrete foundation. It's detected using acoustic equipment that amplifies the sound of escaping water through the slab, combined with pressure isolation testing. We mark the exact location before any concrete is opened — avoiding unnecessary jackhammering.
How much does leak detection cost in Washington DC?
Standard leak detection runs $150–$350 for most residential calls. Slab leak detection requiring acoustic equipment runs $300–$600. Repair costs depend on the leak type and access difficulty — ranging from $200 for a simple fixture repair to $1,800 or more for slab access or pipe rerouting. Written quote before any work starts.
Can you schedule leak detection priority during business hours?
Yes — we prioritize leak detection calls for same-week scheduling, Monday through Friday. For an active leak causing visible damage or a significant bill spike, call us at 240-888-9739 between 9am and 5pm and we'll get you on the schedule as quickly as possible.
My water bill went up — is that definitely a leak?
Not necessarily — but an unexplained increase with no change in household habits is one of the most reliable early indicators of a hidden leak. Run the meter test first: turn off everything, note the meter reading, wait 30 minutes, and check again. If the meter moved, you likely have an active leak.
IMAGE PLACEHOLDER: Repaired pipe after concealed wall leak in DC rowhouse — minimal access opening, clean repair visible
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IMAGE PLACEHOLDER: Water stain on DC home ceiling — classic brown stain on white drywall, pre-detection photo
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5.0
★★★★★
11 Google Reviews
★★★★★
"They found the leak in my basement slab in 45 minutes — the other company was about to tear up the whole floor."
Verified Google Review
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Suspicious of a Hidden Leak? Don't Wait.
Priority weekday scheduling · Non-invasive detection first · Upfront pricing · Licensed DC & MD · Mon–Fri, 9am–5pm