The correct way to repair water pipe cracked and leaked

TURN OFF THE WATER SUPPLY. This is non-negotiable.
- Local Shut-off: If the leak is at a fixture (sink, toilet), turn the shut-off valves clockwise.
- Main Shut-off: If the leak is in a wall or ceiling, you must turn off the main water valve to the entire house. Know where this is before an emergency.
DRAIN THE LINE. Open the faucet at the lowest point in the house (e.g., a basement sink or outside hose bib) and a faucet at a higher level to allow air into the system and drain the water out of the leaking section.
TURN OFF ELECTRICITY. If the leak is near any electrical wiring, outlets, or appliances, shut off the power at the circuit breaker to avoid electrocution.
DRY THE AREA. Use towels to thoroughly dry the pipe. Most repair methods require a completely dry surface.

This determines which repair methods and materials you can use.

Copper: A reddish-brown, rigid metal pipe. Joins with solder (sweat fittings) or compression fittings.
PEX: A flexible plastic pipe, often blue (cold), red (hot), or white. Joins with crimp, clamp (cinch), or push-to-connect fittings.
CPVC: A rigid, off-white or light yellow plastic pipe. Joins with solvent cement (special glue) and threaded fittings.

Here are the best methods, from temporary fixes to permanent repairs.

This is a quick, hard-setting putty useful for small pinhole leaks on any pipe type as a temporary solution until a permanent repair can be made.

How it Works: You knead the two-part epoxy together until it's a uniform color, then mold it directly over and around the crack.
Best for: Small holes, odd-shaped pipes, or as a holdover.
Procedure:
1. Ensure the pipe is dry and clean. Sand the area lightly with emery cloth.
2. Knead the putty as directed.
3. Press it firmly over the leak, wrapping it around the pipe. Smooth it out.
4. Let it cure for the time specified on the package before turning the water back on.

A sturdy, metal clamp with a rubber gasket that seals the leak. Very effective for larger cracks or bursts.

How it Works: The rubber gasket is placed over the leak, and the metal clamp is bolted tightly around it to create a seal.
Best for: Larger cracks, high-pressure lines. Good for all pipe types.
Procedure:

Clean the pipe surface around the leak.
Position the rubber gasket over the crack.
Place the metal clamp over the gasket and tighten the bolts evenly with a wrench until snug.

Similar to a clamp, it's a sleeve lined with a rubber gasket that wraps fully around the pipe.

How it Works: It provides 360-degree coverage, which can be better for cracks that run along the pipe.
Best for: All-around cracks. Good for all pipe types.

For a guaranteed, long-term fix, you must cut out the damaged section and replace it with a new piece of pipe and the correct fittings.

A. For Copper Pipes:

Tools/Materials: Tubing cutter, pipe cleaner (emery cloth), flux, solder, propane torch, sweat couplings, new section of pipe.
Procedure:
1. Use the tubing cutter to make clean, square cuts on either side of the crack.
2. Clean the ends of the existing pipe and the new pipe with emery cloth until shiny.
3. Apply flux to the cleaned ends.
4. Slide a sweat coupling onto each existing pipe end.
5. Slide the new piece of pipe into the couplings.
6. Heat the coupling evenly with the torch and touch the solder to it. The flux will draw the solder into the joint. Let it cool.

B. For PEX Pipes:

Tools/Materials: PEX pipe cutter, two crimp rings, two PEX couplings, PEX crimping tool.
Procedure:
1. Cut out the damaged section with the PEX cutter.
2. Slide a crimp ring onto each end of the existing pipe.
3. Insert a PEX coupling into each pipe end.
4. Slide the crimp rings over the collar of the coupling.
5. Use the crimping tool to compress the ring firmly, creating a permanent seal.

C. For CPVC Pipes:

Tools/Materials: CPVC pipe cutter, CPVC solvent cement, primer, two CPVC couplings.
Procedure:
1. Cut out the damaged section.
2. Dry-fit the new section with couplings to ensure proper fit.
3. Apply purple primer to the outside of the pipe ends and the inside of the couplings. Let it dry.
4. Apply a thick, even layer of CPVC cement to the same areas.
5. Quickly push the couplings onto the pipe ends and give them a quarter turn to spread the cement. Hold firmly for 15 seconds. Note: CPVC cement sets very fast.

These are excellent DIY solutions. They work on copper, CPVC, and PEX without any special tools (just a cutter).

How it Works: You cut the pipe, push the fitting onto the end, and it's done. An internal O-ring and metal teeth create a perfect seal.
Procedure:
1. Cut the pipe cleanly and square.
2. Deburr and mark the pipe for insertion depth.
3. Push the fitting on firmly until it bottoms out. It's that simple.
Drawback: They are significantly more expensive than traditional fittings.

Shut Off Water & Drain Pipes.
Identify Pipe Material.
Cut Out Damaged Section. Use the appropriate cutter for a clean, square cut.
Prepare the New Section. Measure and cut a new piece of identical pipe type to fit the gap.
Install New Fittings. Use the correct method (solder, crimp, cement, or push-to-connect) to install couplings on both ends and attach the new pipe section.
Turn Water Back On Slowly. Open the main valve slightly to slowly pressurize the system and check for leaks at your new joints.
Check for Leaks. Once confirmed there are no leaks, open the valve fully.

Do not use tape alone. Standard thread seal tape is for threaded joints, not for wrapping cracks.
Do not rely on temporary fixes long-term. Epoxy and clamps can fail without warning.
Do not solder pipes with water in them. The water will draw heat away and make a proper solder joint impossible, leading to failure.