How to Fix a Leaky Pipe: Temporary and Permanent Fixes

Knowing how to fix a leaky pipe can be the difference between a damp spot under the sink and thousands of dollars in water damage. A pinhole leak can spray or drip for weeks unnoticed inside a wall, soaking framing, drywall and insulation. The good news: most accessible pipe leaks can be stopped in minutes with a temporary patch, then repaired permanently on your own schedule.

First: Stop the Water

Before touching anything, shut off the water supply to the leaking pipe. For a fixture leak, use the shutoff valves under the sink or behind the toilet (turn clockwise). For a leak in a supply line with no local valve, or any leak you can't isolate, shut off the main water valve — usually near where the water line enters the house, in the garage, basement or a utility closet.

Then relieve pressure by opening the lowest faucet in the house (often an outdoor hose bib or basement laundry tap) and letting it run until it stops. For drain pipe leaks (ABS/PVC), there's no pressure to relieve — but put a bucket under the leak and don't run water through that drain until it's fixed.

Safety note: if water is near electrical outlets, the breaker panel or light fixtures, turn off the breaker for that area before working. Water and electricity is the one combination where you stop and call a professional immediately.

Assess the Leak

Dry the pipe with a rag and watch where water appears. You're looking for three things:

• Where is it leaking? A pinhole in the middle of a straight pipe run is the easiest fix. A leak at a joint or fitting is also common. A split or crack along the pipe needs a section replaced.
• What kind of pipe? Black plastic is ABS (drain only). White plastic is PVC (drain, or CPVC cream-colored for supply). Reddish-brown metal is copper. Galvanized steel is gray metal. The material determines your permanent fix.
• Supply or drain? Supply lines are pressurized — temporary patches are truly temporary here. Drain lines (ABS/PVC) only carry water when fixtures run, so patches hold more reliably.

If the pipe is frozen, don't just patch the split — you need to thaw it safely first. See our frozen pipe guide before proceeding.

Temporary Fix 1: Epoxy Putty

Epoxy putty (like JB WaterWeld) is a hand-kneadable compound that hardens into a waterproof seal. It works on pinholes and small cracks, sets even on damp surfaces, and costs under $10. Every homeowner should keep a tube in the toolbox.

1. Shut off the water and dry the pipe as much as possible. Rough the area around the leak with sandpaper for better adhesion.
2. Cut off the needed amount and knead it until the color is uniform (usually 2–3 minutes).
3. Press the putty firmly over the leak, spreading it at least an inch beyond the hole in every direction. For a pinhole, a walnut-sized ball flattened over the spot is plenty.
4. Let it cure per the package directions (typically 15–60 minutes) before turning water back on.

Epoxy holds well on drain lines for months and on supply lines for days to weeks — long enough to plan a proper repair. It is not a permanent fix on pressurized pipe.

Temporary Fix 2: Pipe Repair Clamp

A pipe repair clamp (or split-sleeve clamp) is a metal sleeve with a rubber gasket that bolts around the pipe over the leak. It's the most reliable temporary fix for pressurized supply lines and takes five minutes to install.

1. Buy the right size clamp for your pipe's outside diameter — measure or bring a photo to the store. Clamps are sized by pipe diameter (e.g., 1/2", 3/4", 1").
2. Center the rubber gasket over the leak and wrap the clamp around the pipe.
3. Tighten the bolts evenly, alternating sides, until snug. Don't overtighten on plastic pipe — you can crack it.
4. Turn the water back on slowly and check for seepage around the gasket edges.

Repair clamps can hold for months on supply lines, but treat them as a bridge to a permanent repair, not the final answer.

Temporary Fix 3: Self-Fusing Silicone Tape

Self-fusing silicone tape (often sold as "rescue tape") bonds to itself under tension, forming a watertight rubber sleeve. It's excellent for small leaks in tight spots where a clamp won't fit, and it works on wet pipe.

1. Stretch the tape to double its length as you wrap — the stretching activates the self-fusing bond. This is the step everyone skips and the reason it "doesn't work" for some people.
2. Wrap tightly with 50% overlap, extending 2 inches past the leak on both sides. Build up 4–6 layers.
3. Press the end down firmly and give it a few minutes to fuse before restoring water.

Good for pinholes and hairline cracks. Not suitable for splits, large holes, or high-pressure leaks near the main.

Permanent Fix: Cut and Replace the Damaged Section

The only true permanent fix for a damaged pipe is removing the bad section and installing new pipe. This sounds intimidating but is very doable — it's the same basic skill as gluing ABS pipe, which we cover step by step.

Tools you need: pipe cutter or hacksaw (plastic) / tubing cutter (copper), two couplings or repair fittings, solvent cement + primer (plastic) or solder + flux + torch (copper), sandpaper or emery cloth, measuring tape, marker, bucket and rags.

1. Shut off water and drain the line. Open the lowest faucet to empty the pipe.
2. Mark your cuts at least 2 inches beyond the damage on each side — cut back to clean, solid pipe.
3. Cut out the damaged section. For plastic, a hacksaw or plastic pipe cutter works; for copper, use a tubing cutter for a clean square cut. Deburr the cut edges.
4. Dry-fit the replacement. Cut a new piece of the same material and diameter to span the gap, plus two couplings (slip couplings for plastic, or sweat/solder couplings, push-fit, or compression couplings for copper).
5. Join it permanently: solvent-weld plastic with primer and cement (see our ABS gluing guide), or for copper use push-fit fittings (SharkBite-style) if you want to avoid soldering — they're code-approved and need no torch.
6. Restore water slowly and check every joint for drips. Check again after an hour.

Fixing Leaks by Pipe Material

Never mix materials incorrectly: ABS and PVC need the right transition cement or a mechanical coupling — regular ABS cement won't bond PVC and vice versa. Our guide on mixing ABS and PVC explains the right way.

Common Mistakes to Avoid

• Patching without shutting off the water. Patches applied under pressure almost always fail — and you'll get soaked.
• Using duct tape or electrical tape. Neither is waterproof under pressure. They'll hold for minutes, maybe.
• Overtightening clamps on plastic pipe. Plastic cracks under excessive clamp force — snug is enough.
• Ignoring the cause. A pinhole in copper often means the pipe is corroding from the inside — more leaks will follow. Multiple pinholes mean it's time to repipe, not patch. See our repiping guide.
• Forgetting to check after the repair. Always recheck joints after an hour and again the next day. Slow seeps take time to appear.

When to Call a Professional

• Water is near electrical wiring, outlets or the breaker panel.
• The leak is inside a wall or ceiling and you can't see its full extent.
• The pipe is burst, split lengthwise, or leaking at multiple points.
• It's a gas line — never DIY gas. Ever.
• The main water line (before your shutoff valve) is leaking — that's often the water utility's or a pro's job.
• You've patched the same pipe twice and it keeps leaking — the system needs replacement, not another patch.

A plumber typically charges $150–350 to repair an accessible pipe leak, more if walls or ceilings need opening. Compare that to the cost of water damage from a failed DIY patch on a supply line — when in doubt on pressurized pipe, the pro is the cheaper option.