How to Fix a Broken Pipe Under the House
Quick answer
To fix a broken pipe under your house, shut off water at the main valve, then find the break in the crawlspace. Small leaks take a push-fit fitting or pipe clamp, costing $50 to $200. Larger breaks need a coupling or soldering. Dry the area within 24 to 48 hours, and call a plumber for main lines or copper work.
Key takeaways
- Shut off water at the main valve immediately, usually in the basement, crawlspace, or near the water heater. This is the first move in any burst pipe emergency.
- Small accessible leaks cost about $50 to $200 to fix with a push-fit fitting; larger breaks commonly run $400 to $1,500 for a plumber, plus $1,000 to $2,000 for water damage cleanup.
- Mold can begin growing within 24 to 48 hours of water damage, according to the EPA, and a saturated crawlspace can take 7 to 14 or more days to dry with industrial dehumidifiers.
- Match your repair to your pipe material: PEX uses crimping or push-fit fittings, PVC uses cement and primer couplings, and copper needs soldering with a torch.
- Homeowners insurance usually covers the water damage a burst pipe causes but typically not the cost of repairing the pipe itself, so check your own policy.
On this page
- Step 1: Shut Off the Water Supply Immediately
- Step 2: Locate the Broken Pipe Under the House
- Step 3: Take Action in the First 24 to 48 Hours
- Step 4: Gather Tools and Materials for Your Repair Method
- Step 5: Fix the Broken Pipe Based on Its Material
- Step 6: Test the Repair and Watch for Pressure Leaks
- Step 7: Dry the Affected Area to Prevent Mold and Material Damage
- Step 8: Assess Water Damage Categories and Safety Hazards
- Step 9: When to Call a Professional Plumber
- Step 10: Understand Costs and Insurance Coverage
- When to call a professional
- Frequently asked questions
Step 1: Shut Off the Water Supply Immediately
Your main shut-off valve is typically in the basement, crawlspace, or utility room near the water heater. Turn it clockwise to stop the water. This is the very first thing you do when you find a broken pipe under your house.
Finding Your Main Valve
Check the basement, crawlspace, the area near the water heater, or at the curb, where the municipal shutoff sits. If you cannot find it right away during an emergency, call a plumber instead of searching while water keeps running.
Learning this location before an emergency saves precious minutes. See where to find your main water shutoff valve if you have not located yours yet.
Turning It Off
Most valves turn clockwise to close. Some homes use a lever-style valve instead; pull it down or sideways to stop the flow. Practice locating and turning this valve before an emergency happens, not during one.
Once the water is off, open the lowest faucet in the house to drain the remaining water from the line. This relieves pressure and makes the next step, locating the break, easier and safer.
Step 2: Locate the Broken Pipe Under the House
Look for pooling water, wet soil, or a hissing or spraying sound in the crawlspace. A bright flashlight and a slow visual sweep are your first tools, since water often travels before it shows up where it started.
| Sign | What It Means |
|---|---|
| Visible water pooling or puddles | An active leak is near the surface; this may be close to the burst location |
| Hissing or spraying sound | Pressurized water is escaping, which helps narrow down the location |
| Wet soil or soft spots | Water has already spread into the foundation area or subgrade |
| Musty smell or discoloration | The leak has likely been running for hours already |
Visual Inspection in the Crawlspace
Bring a bright flashlight or a clamp light. Water runs to the lowest point, so you may not see the exact burst location right away; trace the moisture back upstream toward its source.
A typical crawlspace gives you only 18 to 24 inches of clearance, according to MB Construction, so bring knee pads and protective gear and expect slow, careful movement.
If moisture seems to be spreading from multiple spots or you are unsure what you are looking at, review how to spot hidden water damage in a crawlspace before you keep searching.
When to Suspect a Hidden Leak
If you see pooling water but cannot find the pipe, or water is dripping from above, hire a plumber with thermal imaging or acoustic leak detection equipment. Guessing at a hidden leak wastes time you do not have.
Step 3: Take Action in the First 24 to 48 Hours
The EPA says mold generally will not grow if wet materials are dried within 24 to 48 hours of a leak. Drying the area inside that window limits damage and improves your odds with an insurance claim.
Immediate Actions (First Hour)
- Shut off the water, as described above.
- Remove standing water with a pump, wet vac, or mop.
- Open windows and doors, or crawlspace vents, for ventilation.
- Photograph and video the damage for your insurance record.
Within 24 Hours
- Decide whether the water is clean (a burst supply line) or contaminated (sewage or gray water).
- For contaminated water, contact a professional remediation company instead of handling it yourself.
- For clean water, open crawlspace access and position fans and a dehumidifier to start drying.
- Call your homeowners insurance company to report the claim.
Within 48 Hours
Finish drying everything you can reach. Check drywall, flooring, and the subfloor for soft spots or discoloration, both signs of saturation. Past this point, wet materials are more likely to need replacement rather than simple drying.
Past that same 48-hour mark, mold becomes a real risk rather than a remote one. See how fast mold grows after water damage for the full timeline and what stops it.
Step 4: Gather Tools and Materials for Your Repair Method
The tools you need depend on your pipe material and repair method. Push-fit fittings are the easiest DIY option and need no special tools, while permanent fixes for PEX, PVC, or copper each demand different equipment.
| Repair Method | Pipe Types | Tools Needed | Skill Level | Typical Cost |
|---|---|---|---|---|
| Push-fit fitting | PEX, PVC, copper | None; pushes together | Beginner | $50 to $100 |
| PEX crimping | PEX only | PEX cutter, crimping tool | Intermediate | $150 to $300 |
| PVC coupling with cement | PVC only | PVC cutter, sandpaper or emery cloth | Intermediate | $100 to $200 |
| Copper soldering | Copper only | Hacksaw, deburring tool, propane torch | Advanced | $300 to $600 |
| Pipe or repair clamp | Any (temporary) | Wrench, screwdriver | Beginner | $30 to $80 |
DIY-Friendly Option: Push-Fit Fittings
Push-fit fittings such as SharkBite are the fastest and most beginner-friendly repair, since you simply push the pipe into the fitting on both sides without crimping tools, glue, or a torch.
Cut out the damaged section, then push the new piece into the fitting from each side until it locks. These fittings work on wet lines and need no curing time before you test them.
Temporary vs. Permanent Fixes
Clamps work for small leaks and emergencies, but they fail under sustained pressure over time. Treat a clamp as a way to buy time, not as your finished repair.
Complete a permanent fix, whether that is a coupling, soldering, or a professional repair, within a day or two of applying any temporary clamp.
Step 5: Fix the Broken Pipe Based on Its Material
PEX pipe needs crimping with special tools, PVC pipe uses couplings bonded with cement and primer, and copper pipe needs soldering with a torch. Match your method to your pipe type before you start cutting.
| Pipe Type | Steps | Notes |
|---|---|---|
| PEX | Cut out the burst section, slide a crimp ring onto both cut ends, insert the coupling, then crimp the rings and test for leaks | Easiest with a push-fit fitting instead, which skips the crimping tool |
| PVC | Cut out the burst section, sand both ends smooth, apply primer then cement, push the coupling on and hold for 30 seconds, then let it cure 24 hours | This bond is permanent and cannot be undone once set |
| Copper | Cut out the burst section, deburr both ends, apply flux, heat with a torch, solder the joint, then let it cool and test for leaks | Skill-intensive; not recommended for a first-time repair |
PEX Repair: the Simplest Method
If your home has PEX, flexible plastic pipe, a push-fit fitting lets you skip the crimping tool entirely. Cut out the damaged section, push the new PEX into the fitting from both sides until it clicks, then turn the water back on slowly.
A true PEX repair with crimp rings instead requires a dedicated PEX cutter and crimping tool, plus stainless steel cinch clamps, since a crimp connection relies on specialized equipment to seal correctly.
PVC Repair: Chemical Bonding
PVC is harder than PEX and needs primer and cement for a watertight seal. Sand both cut ends, apply primer, then cement, and insert the coupling right away before the cement sets.
You cannot undo this bond once it cures, so double-check your measurements and alignment before you apply any cement.
Copper Repair: Soldering (Advanced)
Copper repair needs a propane torch, solder, and flux. A complete soldering kit covers the torch, deburring tool, and solder wire you need for the joint.
This method is skill-intensive and produces open flame in a tight crawlspace. If you lack soldering experience, this repair is best left to a plumber.
Step 6: Test the Repair and Watch for Pressure Leaks
Turn the water back on slowly at the main valve, watch the repair site for spray or dripping, then check a downstream tap. A repair that holds pressure with no visible leaking is done; anything else needs another look.
Pressure Test Process
- Open the main valve a quarter turn, wait 10 seconds, then open it the rest of the way slowly.
- Check the repair site closely for dripping, spraying, or weeping water.
- Turn on a downstream faucet; water should flow smoothly, without stuttering or low pressure.
- Wait 15 to 30 minutes, then recheck the repair, since a small pinhole leak can take time to appear.
Skipping this verification step is a common mistake that lets an incomplete repair re-damage your home days later, according to licensed plumbers.
If Water Still Leaks
Shut the water off immediately, dry the area, then inspect the joint. Check whether a push-fit fitting is fully seated, or whether a cement or solder joint has a hairline crack.
If you are unsure what is wrong or the leak continues, call a plumber for a professional pressure test rather than repeating the same fix. For a related situation where water keeps running even with the main off, see why water still drips after the main shutoff.
Step 7: Dry the Affected Area to Prevent Mold and Material Damage
Small clean-water leaks dry in 2 to 3 days with fans and ventilation. A saturated crawlspace needs 7 to 14 or more days with industrial dehumidifiers, and materials wet beyond 48 hours typically need replacing.
| Scenario | Drying Time | Material Replacement |
|---|---|---|
| Small clean-water leak, accessible area | 24 to 48 hours with fans and ventilation | Usually not needed if dried within 48 hours |
| Moderate water, crawlspace or wet drywall | 3 to 7 days with a dehumidifier | Drywall likely needs replacing if saturation is visible |
| Heavy saturation, standing water, wet subfloor | 7 to 14 or more days with an industrial dehumidifier | Subfloor, insulation, and drywall usually need removal |
| Contaminated water in the crawlspace | 14 to 30 or more days; needs professional remediation | All affected materials must be discarded and replaced |
How to Dry Quickly
Position box fans or shop fans to move air through the crawlspace, run a dehumidifier sized for the space, and open crawlspace vents to help air circulate. Industrial dehumidifiers cut drying time significantly compared to fans alone.
For the full breakdown of how drying speed connects to mold risk across a whole house, see how fast you need to dry a house to stop mold.
Deciding Whether to Replace Drywall or Subfloor
Check affected materials for softness, sagging, or visible mold. BRK Drywall recommends replacing drywall that shows any of these signs or that stayed wet for more than 24 to 48 hours. Do not try to dry moldy material; remove and replace it instead.
For the full decision process on a damaged wall, see repairing versus replacing water-damaged drywall, including exact moisture meter thresholds.
Once the crawlspace is dry, keep humidity under control so a slow leak does not sneak up on you again. See controlling indoor humidity to prevent mold and moisture damage for the EPA's 30 to 50 percent target range.
Step 8: Assess Water Damage Categories and Safety Hazards
Category 1 is clean water from a broken supply line, generally safe to handle yourself. Category 2 is gray water from a non-potable source and needs professional cleanup. Category 3 is sewage, which is toxic and always needs professional remediation.
| Category | Typical Source | Safety Risk | Required Action |
|---|---|---|---|
| Category 1 (clean) | Broken water supply line, appliance overflow | Low, from the clean water alone | You can usually handle cleanup if dried within 24 to 48 hours |
| Category 2 (gray) | Broken sump pump, seepage from a non-potable system | Biological hazard | Professional cleaning and assessment recommended |
| Category 3 (black) | Broken sewer line, sewage backup | Severe health hazard | Professional hazmat remediation required |
How to Identify the Water Category
Water from your main supply line, the pipe you are repairing, is Category 1 and safe to handle. If water is backing up from floor drains or toilets, or looks dark, treat it as Category 2 or 3 and call a professional right away.
Crawlspace Safety Hazards
Shut off electricity to the crawlspace breaker before entering a wet crawlspace; standing water near wiring is an electrical shock risk. Avoid touching wet outlets or appliances entirely.
For sewage contamination, wear gloves and a respirator rather than attempting cleanup yourself. Category 3 water always needs a professional remediation crew.
Step 9: When to Call a Professional Plumber
DIY repair works for small, accessible leaks in PEX or PVC pipe using a push-fit fitting. Call a plumber for a main water line, copper soldering you are not comfortable with, contaminated water, or structural damage.
DIY Repair: When It Is Safe
- The burst is in an area with comfortable crawlspace clearance
- The pipe is PEX or PVC rather than copper that needs soldering
- The water is clean, from your home's supply line rather than a sewer or drain line
- You have some plumbing experience or are comfortable learning a new skill
- The burst is inside your house, not on the water main between the street and your home
Call a Professional When
- The burst is in your main water line, running from the street to your house
- The burst is in copper pipe and you lack soldering equipment and experience
- The crawlspace offers less than 18 inches of clearance to work in
- The water is contaminated, dark, or coming from a drain or sewage line
- You see structural damage, such as sagging framing or a soft foundation area
- Water has been sitting more than 48 hours and materials are already saturated
- You are unsure about the location or severity of the burst
A broken water main or service line is worth calling about immediately. That section of pipe runs from the street to your house, and in most areas it costs more to fix than an interior line and may involve the utility, not just a plumber.
Step 10: Understand Costs and Insurance Coverage
A DIY push-fit repair runs $50 to $200 in parts. Professional repairs for a burst interior pipe commonly cost $400 to $1,500, plus $1,000 to $2,000 for water damage cleanup, based on typical contractor pricing. Homeowners insurance usually covers the damage, not the pipe repair itself.
| Repair Type | Cost | Best For |
|---|---|---|
| DIY push-fit repair | $50 to $200 (parts only) | Small, accessible leaks |
| DIY PEX crimping (if you own the tools) | $100 to $300 (parts plus rental) | PEX pipe, moderate damage |
| Professional repair, interior line | $400 to $1,500 | Larger breaks, difficult access |
| Main water line repair or replacement | Commonly more than an interior repair; replacement runs well into the thousands | Breaks between the street and your house |
| Water damage cleanup and drying | $1,000 to $2,000 or more | Saturation, dehumidification, material removal |
| Drywall, subfloor, or framing replacement | $500 to $3,000 or more | After saturation or mold discovery |
What Insurance Covers
Homeowners insurance typically covers damage caused by a burst pipe, according to Policygenius, including your drywall, flooring, insulation, and belongings. It generally does not cover repairing or replacing the pipe itself, since that counts as maintenance.
Insurers may deny a claim if the leak was slow, a maintenance issue, rather than sudden, a covered event. For the full picture of what can go wrong with a claim, see why a water damage insurance claim gets denied over mold.
Reducing Out-of-Pocket Costs
Act fast. Drying within 24 to 48 hours can save materials and lower your cleanup bill. Document everything with photos, timestamps, and any contractor quotes you receive.
Getting a plumber's written assessment before filing a claim can help prove the damage was sudden rather than a long-ignored leak, which supports faster claim approval.
Once the repair is done, reduce your odds of a repeat burst. See why pipes sweat and how to stop the moisture damage for everyday prevention steps.
When to call a professional
Clear thresholds for calling a professional plumber:
Call immediately, do not attempt DIY:
- The main water line (the service line from the street to your house) is burst, since you typically do not own or pay for that section yourself.
- The burst pipe is copper and you lack a soldering torch and experience.
- The water is dark, discolored, or backed up from a drain, since Category 2 or 3 contaminated water needs professional remediation.
- Structural damage is visible, such as sagging framing or pooling water inside a foundation crack.
Get a professional assessment within 12 to 24 hours:
- Water damage has spread beyond the burst location and saturation is heavy.
- Drywall or the subfloor is soft or discolored.
- You cannot locate the burst after a visual inspection and listening for sounds.
- The crawlspace offers less than 18 inches of clearance.
- You are unsure whether your repair will hold pressure.
Safe to DIY if all of these apply:
- The burst sits in an accessible area with at least 18 to 24 inches of clearance.
- The pipe is PEX or PVC, not copper.
- The water is clean, from the supply line rather than sewage.
- You have basic tool skill or are willing to learn.
- The water is already shut off and contained, with no active pooling.
Frequently asked questions
Does homeowners insurance cover the cost to repair a broken pipe?
Homeowners insurance typically covers damage to your home and belongings caused by the burst, such as flooring, drywall, and belongings, but not the cost to repair the pipe itself. That part is considered maintenance. Check your specific policy, since claims may be denied if the leak was slow rather than sudden.
What is the difference between a DIY temporary fix and a permanent solution?
Temporary clamps or epoxy hold briefly but fail under water pressure, so do not rely on them for long. A permanent fix matches your pipe type: a push-fit fitting, PEX crimping, a PVC coupling, or copper soldering. Treat any temporary fix as an emergency measure, then complete the permanent fix within a day.
What are common mistakes when doing a DIY pipe repair?
Common mistakes include over-tightening clamps, which can crack old, brittle pipe; using the wrong materials, since duct tape fails under pressure; and skipping the water shutoff first. Not drying thoroughly afterward can lead to mold, and skipping the pressure test means you only find a leak later, once more damage has happened.
Should you heat a crawlspace to prevent future frozen pipes?
Heating prevents freezing but costs more to run all winter. Better strategies include insulating the pipes, sealing crawlspace vents in cold weather, running water slowly on very cold nights, or encapsulating the crawlspace to keep it warmer overall. Know your area's frost line depth to judge your real freeze risk.
What tools do you need if you rent a PEX crimping tool instead of buying one?
A crimping tool typically rents for about $20 to $30 per day from a hardware store or tool rental shop. You will also need a PEX cutter, a deburring tool, and stainless steel cinch clamps. Expect to spend roughly $50 to $150 total in rental fees and supplies for a one-time repair.
Can you use duct tape or epoxy to permanently fix a broken pipe?
No. Duct tape and epoxy are temporary emergency measures only, since both fail under water pressure over time. Use them to buy minutes or hours, never as a finished repair. A permanent fix needs the method built for your pipe material: a push-fit fitting, a coupling, soldering, or crimping.
How do you know if the water from your broken pipe is contaminated?
If the burst is in your main supply line, the pipe carrying household water in, the water is Category 1 and clean. If water is backing up from drains, smells bad, or looks dark, treat it as contaminated and call a professional right away. When unsure, wear gloves and a respirator rather than touching it unprotected.
Sources
- U.S. EPA: A Brief Guide to Mold, Moisture and Your Home
- iCrimp Tools: What Tools Are Needed to Work with PEX
- Home Depot: Soldering Kits
- PVC Fittings Online: How to Connect PEX to PVC or Copper
- PolicyGenius: Are Broken Pipes Under Slab Covered by Home Insurance?
- BRK Drywall: When to Replace Drywall After Water Damage
- MB Construction: Crawl Space Excavation Costs and Benefits
- Princeton Plumbing Pros: How to Fix a Leaky Pipe in a Crawl Space
- Leave the Key: How to Fix a Leaking Water Pipe Under a House