Shut off the water to the leak first, then dry the pipe. For a small hole or weep in an exposed pipe, epoxy putty, silicone repair tape or a repair coupling can hold until a plumber arrives. Manufacturers call these temporary: corrosion keeps spreading, so the damaged section still needs replacing.
Step one: shut off the water and relieve the pressure
Close the shutoff for the leaking line, or the main valve if you don't know it. Then open a faucet at the lowest point in the house so the pipes drain and the leak stops dripping. If you don't know where your main is, how to test your main water shutoff valve covers the valve types and how to close each one. If the leak is behind a wall or under the slab and you can't see the pipe, leave the water off and call. There's nothing to patch.
The EPA's moisture guidance says to fix plumbing leaks and other water problems as soon as possible, and that dried within 24 to 48 hours, wet materials in most cases won't grow mold. So after you've stopped the flow, start mopping and running fans.
Temporary options, by what you're looking at
Oatey, a plumbing parts maker, lays out the short-term options. Its emergency repair guide says that "using putty or silicone tape can also temporarily fix small leaks in water pipes until the damaged section of the line can be repaired appropriately."
| Leak | Temporary option | What the manufacturer says |
|---|---|---|
| Small hole or pinhole in an exposed pipe | Epoxy putty | Can temporarily repair leaks, holes or cracks in plastic and metals. It can be used on wet or dry surfaces. |
| Weeping joint or small split | Silicone repair tape | Bonds to itself and hardens; Oatey says it reaches a complete bond in about 24 hours on average. |
| Short split or damaged length | Repair coupling | Oatey says repair couplings "can effectively temporarily stop leaks," need some mechanical aptitude, and can remain permanent "if properly installed." |
Putty basics, from Oatey: roughen and clean the surface, knead equal amounts of resin and hardener until the color is even, and press it over the hole. The putty stays moldable for roughly 5 to 10 minutes. It starts to harden after about five minutes, and with Oatey's Fix-It Stick, full cure is 24 hours after application. Curing times vary by maker, so read the label before you turn the water back on.
What a patch can't do
Be honest about the limits. Oatey's epoxy guide says that although putty can seal a water-pipe leak, it "acts only as a" Band-Aid, and that "if corrosion exists where the leak occurs, the corrosion will continue to spread." Its advice is plain: "It is best practice to properly fix the pipe as epoxy putty is only a temporary solution."
That matters in the Valley. Pinhole leaks in older copper are often a sign the pipe is thinning elsewhere, which our page on what causes pinhole leaks in copper pipes explains. A patched pinhole today can be a new pinhole three feet away next month. If it keeps happening, repair or repipe is the real question.
Don't use a temporary patch on:
- A gas line. Gas is a different emergency. Leave the building and call the gas utility or 911.
- A pipe you can't see or reach. Water inside a wall or slab needs leak detection, not tape.
- A joint that sprays under pressure. Keep the water off. A patch that blows out can cause more damage than the leak did.
The permanent fix
Oatey's guide says the proper repair is to cut out and replace the damaged section with the appropriate coupling or pipe material: soldering or pressing for copper, and the appropriate cement or a crimped-in new section for PEX or CPVC. A licensed plumber also checks why it failed, whether that was corrosion, pressure or a bad joint.
HQ Plumbing and Air handles emergency pipe leaks 24/7, finds the failure, and gives you the price up front before work starts. See our leak detection service or our emergency plumber page, or read what to do if water is leaking from your ceiling if the water has already reached the floor below.