When a water pipe leaks, shut off the water at the main, confirm where the leak is, and choose the fix by location. A leak you can see on an exposed pipe may take a clamp or a new fitting. A leak under the house, in the yard or behind a wall is a plumber's job, because the repair and the surface restoration depend on access. Our leaks and burst pipes hub covers neighboring problems, and the home page shows how we arrange a visit.
My water pipe is leaking under my house. What should I do?
Shut off the water at the main and stay out of a crawlspace with standing water near wiring. Check the meter: with all water off, the leak gauge should stop. If it keeps moving, the leak is still live somewhere. A leak under the house needs a plumber to find the pipe, repair it and dry the space, because wet soil and wood framing hold moisture for a long time.
Houses on a raised foundation have a crawlspace where the supply and drain lines run under the floor. In a slab house the pipes may run in or under the concrete, which our slab leak repair company guide covers.
Signs of a leak under the house include a wet or soft spot on the floor above, a musty smell, damp soil at the crawlspace vents, a bill that rose, and the sound of water with the taps off. Do not crawl into a wet space if it is dark, tight or has electrical wiring close by. Photograph from the entrance and tell the plumber what you see.
Keep the crawlspace dry afterward. The EPA says wet building materials should be dried within 24 to 48 hours, and soil and framing under a house dry slowly, so ask for a moisture check.
What should I do if my water pipe is leaking?
Shut off the water at the main, open the lowest tap to drain the line, and find where the water is escaping. Catch drips, protect floors and photograph the leak. If the pipe is exposed and small, a clamp or a fitting may hold until a plumber arrives. If the leak is hidden, leave it off and call a plumber.
Basic order:
- Shut the main valve.
- Drain the line by opening the lowest tap and, for a hot line, shut off the water heater's power or gas control.
- Dry the pipe and look closely: pinhole, split or joint?
- Catch drips and protect what is below.
- Choose a temporary measure only if the pipe is exposed and dry.
- Book a permanent repair.
LADWP's leak check is simple: shut off all water indoors and outdoors, then look at the leak detection gauge on the meter. If it moves with the water off, you have a leak. If the water must be shut off at the meter in an emergency, LADWP says to report an active leak by phone at 800-342-5397 or at a Customer Service Center.
Do pipe leak sealants work?
Sealants can slow or stop a small leak for a while, but they are not a permanent repair of a pressurized water line. Epoxy putty, sealant tape and pastes work best on a dry, clean pipe with the water off while they cure. High-pressure leaks, split pipes and joints that move usually defeat them. Treat a sealant as a way to buy time.
What to know about the main types:
- Epoxy putty or paste. Kneaded and pressed over a pinhole. The pipe has to be dry and clean, and the water off until it cures.
- Self-fusing silicone tape. Wraps tightly around the pipe and bonds to itself. Handy for a small weep on a straight section.
- Clamps with rubber pads. Bolt around the pipe. More dependable than tape for a pinhole.
- Liquid sealers poured into the line. Marketed for tiny leaks inside pipe. Ask a plumber before using any product that goes into a drinking water system.
"High-pressure" sealants do not change the basics. The pipe has to be dry to bond, and water pressure pushes at the patch from inside. Household pressure can be higher than a small patch is made for, especially if the regulator has failed. The California Plumbing Code calls for a pressure regulator where static pressure exceeds 80 psi.
If you patch a pipe, mark the date, note the product and tell the plumber. They will want to replace the section, and they should know what is on the pipe.
What if the pipe is leaking outside, in the yard or near the meter?
If the leak is between the meter and the house, it is on your side of the meter and the repair is yours. LADWP does not repair leaks on private property. Shut the house main, look for a wet patch, a soggy lawn or a meter that moves with everything off, and call a plumber to locate and repair the line.
After an underground leak is repaired, LADWP says you may qualify for a billing adjustment. Requests must be made within 12 months of the leak, with copies of repair receipts. LADWP honors one request per 24 months. Leaking sprinklers, water heaters, faucets, toilets and pool equipment do not qualify.
Ask your plumber to write the location and repair on the invoice, and keep photos of the repaired section. A yard leak may also involve digging near gas and electric lines, so the plumber should mark and check before anyone digs.
Replacing a defective metallic water service line with the same size, quality and conductivity is exempt from the permit under the Los Angeles Municipal Code, and swapping it for plastic is not. Ask which applies to your job. For pricing, see our leak repair cost guide.
What about a leaking pipe joint?
A leaking joint is often the easiest leak to fix, because only the joint is involved. On a threaded steel pipe, the joint may be redone with new thread sealant. On copper, the joint may be re-soldered or replaced. On plastic, a glued joint that weeps usually has to be cut out and replaced. Our guide on how to fix a leaking pipe joint goes through each type.
A joint that leaks right after work, or again and again, may have been poorly prepared the first time, or the pipe may be moving. Do not keep tightening a plastic fitting. Over-tightening cracks it.
What does leaking water pipe repair mean for your home?
For a Los Angeles house, it mostly means knowing what the pipe is made of. Older houses can have galvanized steel, copper, or in some homes polybutylene or other plastic lines, and each fails in its own way. A leak is sometimes the first sign of a line near the end of its life. If one section fails, others nearby may be next.
Ask the plumber what the pipe is, how old it looks, and what the rest of the run looks like. If the line has leaked more than once, a planned replacement can cost less than repeated repairs. See galvanized pipe replacement and repiping a house for the larger option.
We'll arrange a local plumber to visit through the quote page, and a written quote should separate access, repair, permit and surface restoration.
Common questions
How long does a leaking water pipe repair take?
A repair on an exposed pipe is often done in an hour or two. A leak under the house usually takes longer because of access and drying. A leak in a wall or slab takes longer still, since the surface must be opened, the pipe repaired, tested and closed up. Permits and drywall or flooring work add time. Ask for the schedule in your written quote.
What should I ask before I hire someone for leaking pipe repair?
Check the CSLB record at cslb.ca.gov. Ask how the leak will be located, what pipe and fitting will go in, whether a permit applies and what surface repair is included. Get the quote in writing. A deposit above $1,000 or 10 percent of the price, whichever is lower, goes beyond what California allows.
Does someone need to be at the property?
Be there or send an adult you trust. The plumber needs the main valve, the leak area and often a crawlspace hatch or wall access, and the water will be off for some of the visit. You may be asked to approve a change if the pipe is worse than it looked. Tenants should tell the landlord.
Can I use a sealant to fix a leaking pipe permanently?
Not on a pressurized supply line, according to plumbing guidance. Sealants, epoxy and tape can slow a small leak, but they are stopgaps, and they fail at joints and at higher pressure. A permanent repair replaces the damaged section or fitting. Use a sealant only to buy time, and book a proper repair.
Is a leak under the house covered by LADWP?
No. LADWP does not repair leaks on private property. After an underground leak on your property is repaired, you may qualify for a billing adjustment, which is separate from the repair itself. The request must come within 12 months of the leak, with repair receipts. Sprinklers, water heaters, faucets, toilets and pool equipment do not qualify.