24/7 emergency line · Phone answered · Woodbridge, VA
40+ Years in the Trade Family Owned Residential · Commercial
Plumbing Heating & Air Commercial Residential Service Area About Contact Book Now
Plumbing

Leak Detection

Two things have to be settled before anybody cuts into a wall or a slab: whether water is genuinely leaving your pipes, and where it is going. You can answer the first yourself in an hour at the meter, for nothing.

A hidden leak bills you twice. The water turns up on the next statement from Prince William Water. The damage turns up months later in the subfloor and the framing, long after the cause is buried. The Insurance Information Institute puts water damage and freezing claims at an average of $15,400 across 2019 to 2023.

Prove it at the meter before you call anybody

Acoustic leak detection receiver and headphones on a basement slab beside a ground microphone
Acoustic detection equipment on a basement slab, ground microphone at the mark.

You do not need us for the first step and should not pay anyone for it. The meter settles whether water is leaving your pipes at all, which is a different question from where.

  1. Shut the house downEvery tap off. No dishwasher, no laundry, no shower. Think about what runs on its own: an ice maker, a humidifier, an irrigation timer.
  2. Watch the small dialMost meters carry a triangular or disc-shaped indicator that spins on flow too low to move the main dial. Turning with the house shut down means water is moving.
  3. Wait an hour, read againA reading that has changed is the proof. Location is still unsettled, but the argument over whether there is a leak is finished.
  4. Close the main valve at the buildingRead once more. Still creeping means the leak is outside, between meter and house. Stopped dead means inside.

Those four readings are worth more to us than anything you can describe on the phone. EPA's WaterSense program puts the average household's leaks at more than 9,300 gallons wasted a year, says nine percent of homes waste 50 gallons or more per day, and estimates that fixing the straightforward ones saves about 10 percent on a water bill. EPA's household leak page has the rest.

What each tool can settle, and what it cannot

A list of equipment is not a diagnosis. Each method answers one narrow question, and knowing which question is the difference between a small access cut in the right place and a floor opened twice.

What each method settles, and where it stops
MethodWhat it can establishWhere it stops
Meter and valve isolationThat water is leaving the system, and whether the loss is on the utility side of the meter or on yoursProves a leak exists. Says nothing about where in the house it is
Sectional pressure testingWhich branch of the supply piping will not hold pressureNarrows it to a branch, not to a foot of pipe. Nothing to measure on a drain or waste line, which carries no pressure to lose
Acoustic listening, ground microphonePosition of a pressurized leak under a slab or under soil, usually within a small areaNeeds the line pressurized and the house quiet. Carpet, deep fill over the pipe and road noise all degrade it
Thermal imagingSurface temperature difference, which picks up a hot water line under a slab quicklyIt reads heat, not water. A cold line leaking under tile in a cool room can be close to invisible, and a sunlit wall reads as a false hit
Camera inspection in a drain or sewerPipe material, diameter, the type of defect and the footage from the access point to itEPA states it “cannot capture pipe condition below the water” and that the assessment “is subjective and can be error prone”. The line has to be cleaned and running low first

Two things follow from that last row. A quick look down a cleanout is not a camera inspection: EPA's operations guidance puts the reach of that at the first 10 to 12 feet and notes it misses the invert, the bottom of the pipe where sags and cracks sit. A camera run through a line still full of water gives you footage, not a diagnosis. EPA's sequence is clean first, inspect after, with the record naming pipe size, pipe material and footage to each defect. EPA recommends camera work for lines 4 to 48 inches across, which a house lateral just scrapes into and the branch under your sink does not.

The leaks that actually turn up in houses around here

IBHS studied residential water loss claims and found 65 percent came from a failure of the plumbing supply material itself, against 18 percent from frozen pipes. Cost ran the other way: material failures averaged $4,296, a freeze and burst $8,189, and 39 percent of frozen claims landed in January. Those claims date from 1998 to 2005, so the dollars are old money. The ratio holds, which is why a January burst is a different conversation. On slab-built houses: 22 percent of supply material failures happened beneath the slab of homes with no basement.

  • Braided supply lines under sinks and behind the washer. The steel braid is abrasion protection, not the pressure boundary. Inside is a plastic hose with rubber gaskets at the threads, and that is what gives up. IBHS blames wear, damage from shoving an appliance back into place, excessive pressure, heat and cold extremes, and water quality. Nobody publishes a service life, so a quoted number of years was invented.
  • Toilets. In IBHS's consumer figures, 78 percent of water damage incidents involving a toilet traced to faulty supply lines, flanges, fill valves or an overflow. The supply line is the pattern across every fixture in that study.
  • Copper pinholes. A Virginia Tech master's thesis records that in 2004 it was proven water alone can eat a pinhole through copper, with no defect in the tube and no bad install required. Pitting is driven by chlorine and inhibited by orthophosphate, so it is water chemistry, not copper wearing out. One Maryland utility's outbreak caused leaks in 20 to 50 percent of the homes it served.
  • Polybutylene. Grey, sometimes white or blue, usually stamped PB2110, made from 1978 to mid-1995. No inspection clears it: InterNACHI is blunt that it deteriorates from the inside and cannot be assessed without dismantling the pipe. Finding your leak tells you where this one failed, not whether the rest is sound. Honest reason to weigh a repipe. Dishonest reason to insist on one.
  • Galvanized steel. Common until the 1950s, so anything still carrying water is past seventy years old. It rusts from the inside out, the bore narrows with the deposits EPA calls tubercles, and the water runs rusty. No authority publishes a service life for it, InterNACHI's own chart included. Era is the tell: pipe materials by decade.
  • The buried service line. Between meter and building, which in Prince William Water's territory is the part you own. Virginia's code puts water service pipe at least 12 inches deep and not less than 6 inches below the frost line, so a leak can surface as one green strip of lawn, or as nothing. Past a spot repair we say so: water line replacement.

Pressure causes more leaks than people expect

We check static pressure before chasing anything, because high pressure quietly manufactures leaks all over a house at once. Prince William Water's utility standards require a pressure reducing device where working pressure exceeds 80 psi, and the Virginia Residential Code sets the same ceiling on static pressure. Watts, which makes the valves, treats anything over 60 psi as generally high and names leaking water heaters, banging pipework and dripping faucets among the symptoms. That is this utility's own standard, so do not assume it reads the same one county over.

Two things about that valve get stated wrongly almost everywhere. A reducing valve that has drifted is usually a rebuild, not a replacement: Watts calls its own valves life-of-mortgage products serviced with an inexpensive kit, the opposite of the ten-to-fifteen-year swap schedule you will read elsewhere. And once a reducing valve or check valve sits on the service the house is a closed system, so the water heater has nowhere to push water as it expands and the code requires a means of thermal expansion control. A waterlogged expansion tank reaches us as a weeping relief valve reported as a water heater leak.

What happens once we find it

Detection and repair are the same visit where the work allows, because we are a plumbing contractor and not a detection service. On permits, the straight answer: the Virginia Uniform Statewide Building Code requires one for alterations to the water supply and distribution system, the drainage system or the vent system, so a reroute is permitted work while swapping a fixture without touching pipe generally is not. Emergency work may start, with the application filed by the end of the first working day. We file it, and nothing is closed up before the inspector has looked.

Sometimes locating the leak is the easy part. One pinhole in old copper is a repair. The third pinhole in the same run is an argument for repiping, and we will say so even though the repair is the smaller invoice. Our office runs 7:00 to 17:00 and Jon takes the after-hours calls himself, so a person answers rather than a service. That is not a promise of a truck in your driveway at 3am.

Common Questions

Can I confirm a leak myself before paying anyone?
Yes, and you should. Shut off every fixture, note the meter reading, watch the small low-flow indicator, read again an hour later. Movement means water is leaving the system. Then close the main valve: still moving means outside, stopped means inside.
My water bill jumped but nothing is wet. Is that possible?
It is the normal case, not the odd one. A leak under a slab or in the buried service line has somewhere to go, so there is nothing to see indoors for months. EPA reports nine percent of homes waste 50 gallons or more a day.
Can you find it without tearing up my floor?
That is the point of isolating first: narrow it to a branch by pressure, pinpoint acoustically or thermally, open one small access. We will not pretend the methods are infallible. We say how confident we are before a saw comes out.
Does a camera find water leaks?
Not pressurized ones. A camera goes into drains and sewers, and EPA is clear it cannot capture pipe condition below the water line and that reading footage is subjective and operator dependent. Supply leaks are found by pressure isolation and listening.
Why clean the drain before the camera goes in?
Because that is EPA's own sequence, and a camera cannot see through standing water or past a blockage. Your report should name pipe size, pipe material and the footage to each defect, and you should keep the recording.
The leak is outside, between the meter and the house. Whose is it?
Yours, in most of our area. Prince William Water owns the line from the main to the meter and the customer owns meter to building. That is why the valve-isolation step matters: it settles ownership in two minutes.
Could high water pressure be causing my leaks?
Often, and worth checking before anything is replaced. Prince William Water requires a pressure reducing device above 80 psi working pressure, and the Virginia Residential Code caps static pressure at the same figure. Watts counts anything over 60 psi as high.
Does a pressure reducing valve need replacing on a schedule?
No, and the schedule quoted elsewhere is not the manufacturer's. Watts describes its valves as life-of-mortgage products cleaned or rebuilt with an inexpensive kit, so replacement is a condition call. With one fitted, the code also requires thermal expansion control.
My house has polybutylene. Can you inspect it and tell me it is safe?
No, and neither can anyone else. The grey pipe stamped PB2110 was made from 1978 to mid-1995, and InterNACHI's position is that it deteriorates from the inside and cannot be assessed without dismantling it. We can find your leak. We cannot clear the rest.
Is one copper pinhole a sign the whole house needs repiping?
Not by itself. Virginia Tech research established that water chemistry alone can perforate copper with no defect and no installation error, and a peer-reviewed case found neighboring older homes on identical water that never pinholed. A pattern in one run is the warning.
Do I need a permit to repair a leak?
It depends what gets altered. Virginia's code requires a permit for alterations to the water supply and distribution system, the drainage system or the vent system, so cutting in new pipe or rerouting a line is permitted work. Emergencies may start first.
What should I do right now, before anyone gets here?
Close the main shutoff at the building. If the water heater is electric and the tank is losing water, kill its breaker, because the elements are not meant to run dry. Photograph everything while it is wet. Then call (703) 491-6542.
Book a service call

Think You Have
A Hidden Leak?

One call covers plumbing and HVAC. Talk to somebody who has been doing this for decades.

Call (703) 491-6542 Book Online
Call Now Book