📋 What is Plumbing Damage?

Plumbing damage occurs when a licensed or unlicensed plumbing contractor performs defective work that results in water leaks, property damage, or code violations. Under California law, plumbing contractors must comply with the California Plumbing Code (CPC), manufacturer specifications, and industry standards. Failures can result in significant liability including repair costs, water damage remediation, mold removal, and in some cases, treble damages.

When This Guide Applies

This guide applies if your plumbing contractor has:

💧 Caused Water Leaks

Supply line, drain line, or fixture leaks due to improper installation, poor connections, or substandard materials

❌ Code Violations

Work that fails California Plumbing Code requirements for pipe sizing, venting, or fixture installation

🚫 Slab Leak Issues

Failed repairs or new installations that leak under the foundation, causing structural damage

⚠ Failed or No Permit

Work done without required permits or work that failed inspection

Common Plumbing Defects

💧 Supply Line Defects

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Water supply line issues can cause catastrophic water damage. Common defects include:

  • Improper soldering of copper joints (cold joints, flux residue)
  • Incorrect PEX crimping or expansion fittings
  • Cross-connection of hot and cold lines
  • Undersized pipes causing pressure issues
  • Missing or improper isolation valves
  • Failure to pressure test before closing walls

🏗 Drain, Waste, and Vent (DWV) Defects

▼

DWV system defects can cause sewage backups, slow drains, and sewer gas infiltration:

  • Improper slope on horizontal drain lines (should be 1/4" per foot)
  • Missing or improperly sized vent pipes
  • S-traps instead of code-required P-traps
  • Improper cleanout placement or accessibility
  • Mechanical joints on buried pipes (not allowed)
  • Improper connection to main sewer line

🛠 Slab Leak Issues

▼

Slab leaks - leaks in pipes running under or through the concrete foundation - are among the most damaging plumbing problems:

  • Poor repair technique leaving weak points
  • Failure to properly sleeve pipes through concrete
  • Inadequate protection from soil conditions
  • Hot water recirculation line failures
  • Copper pipe erosion from aggressive water
  • Failed polybutylene (PB) pipe replacement

⚠ Polybutylene Pipe Issues

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Polybutylene (PB) pipes were installed in California homes from 1978-1995 and are known to fail. Issues include:

  • Pipe deterioration from chlorine in water supply
  • Acetal (plastic) fitting failures
  • Micro-fractures that lead to sudden failures
  • Incomplete replacement leaving some PB in system
  • Improper transition fittings to copper or PEX
  • Insurance coverage exclusions after PB identified

Note: If you discover PB pipes during a repair, the entire system should typically be replaced, not just spot-repaired.

🔧 Water Heater Installation Defects

▼

Water heater installations must comply with strict codes. Common defects include:

  • Missing or improperly installed T&P relief valve discharge
  • No seismic strapping (required in California)
  • Improper venting for gas units (carbon monoxide risk)
  • Missing expansion tank where required
  • No drip pan or improper drain routing
  • Undersized gas line or electrical service

⚠ C-36 Plumbing Contractor License Required

In California, plumbing work over $500 requires a C-36 Plumbing Contractor license. A general contractor (B license) may only perform plumbing as part of a larger project where plumbing is incidental. If your plumber lacks a valid C-36 license:

  • They cannot legally enforce the contract against you
  • They may owe you a full refund of all money paid
  • You can report them to the CSLB for prosecution
  • Criminal penalties up to $15,000 per violation plus jail time

Emergency Repairs vs. Permanent Fixes

⚠ Emergency/Temporary Repair

Stops active water damage. May include shutoff, temporary patch, or bypass. Does NOT constitute permanent fix. You should not pay full price for a temporary repair.

✓ Permanent Code-Compliant Repair

Fully addresses the underlying issue per California Plumbing Code. Includes proper materials, techniques, and permit/inspection where required.

✅ Evidence Checklist

Gather these documents before sending your demand letter or filing claims. Click to check off items as you collect them.

📄 Contract & License Documents

  • ✓ Original signed plumbing contract
  • ✓ Written scope of work/estimate
  • ✓ CSLB license lookup printout (C-36)
  • ✓ Bond and insurance information

💰 Payment Records

  • ✓ All cancelled checks/bank statements
  • ✓ Credit card statements for payments
  • ✓ Invoices from contractor
  • ✓ Emergency repair receipts (if any)

📷 Photo/Video Evidence

  • ✓ Photos of leak source/defective work
  • ✓ Photos of water damage (walls, floors)
  • ✓ Video of active leaks (if safe)
  • ✓ Photos of mold growth (if any)

🏗 Permits & Inspections

  • ✓ Plumbing permit (or proof none pulled)
  • ✓ Inspection reports (pass/fail)
  • ✓ Final sign-off (or lack thereof)
  • ✓ Code violation notices (if any)

💧 Leak Detection Reports

  • ✓ Leak detection company report
  • ✓ Slab leak location documentation
  • ✓ Water meter records showing leak
  • ✓ Pressure test results

📊 Damage Documentation

  • ✓ 2-3 repair estimates from licensed C-36s
  • ✓ Water damage restoration estimates
  • ✓ Mold inspection/remediation quotes
  • ✓ Insurance claim documentation

💡 Pro Tip: Document Water Damage Immediately

Water damage worsens rapidly. Within 24-48 hours, mold can begin growing. Take extensive photos and video before ANY cleanup, then mitigate to prevent further damage. Keep all damaged materials until photographed and documented by restoration company.

📊 Calculating Damages

California law allows you to recover all damages proximately caused by plumbing defects. Water damage claims can be substantial due to the destructive nature of water intrusion.

Damage Type Description
Plumbing Repair/Replacement The cost to properly repair or replace the defective plumbing work. Get at least 2-3 written estimates from licensed C-36 plumbing contractors.
Water Damage Restoration Professional water extraction, structural drying, dehumidification, and antimicrobial treatment. Must be done within 24-48 hours to prevent mold.
Structural Repairs Repair or replacement of damaged drywall, flooring, subfloor, framing, insulation, and other structural components.
Mold Remediation If water intrusion caused mold growth, professional mold testing and remediation can be very expensive. California has specific licensing requirements for mold work.
Slab/Foundation Repair For slab leaks, costs to access pipes under foundation, repair the leak, and restore concrete. May include foundation remediation if damage occurred.
Personal Property Damage Replacement value of furniture, electronics, clothing, and other items damaged by water. Document with photos and receipts.
Temporary Housing If your home is uninhabitable during repairs, you can recover hotel costs, temporary rental, storage, and increased living expenses.
Increased Water Bills If a leak went undetected, you may recover the excess water charges above your normal usage.

📊 Sample Damages Calculation

Example: Slab Leak from Defective Repair

Original plumbing repair cost $1,800
Amount paid to contractor $1,800
Leak detection service $450
Proper slab leak repair (reroute) $4,500
Water damage restoration $8,200
Flooring replacement $6,400
Drywall and painting $3,200
Mold remediation $5,800
Damaged furniture/property $2,100
Temporary housing (10 days @ $180) $1,800
Excess water bills (3 months) $380
ACTUAL DAMAGES SUBTOTAL $34,630
Treble damages (if B&P 7160 applies: x3) $103,890
MAXIMUM POTENTIAL RECOVERY $103,890

⚠ Act Fast to Minimize Damage

You have a legal duty to mitigate damages. When you discover a leak:

  • Shut off water supply immediately (know your main shutoff location)
  • Document everything with photos/video BEFORE cleanup
  • Call a water damage restoration company within 24 hours
  • Notify your homeowner's insurance if claim may be covered
  • Do NOT wait for the contractor to respond before mitigating

📝 Sample Demand Letter Language

Copy and customize these paragraphs for your plumbing damage demand letter.

Opening Paragraph - Formal Notice
RE: FORMAL DEMAND FOR DAMAGES - DEFECTIVE PLUMBING WORK

Dear [CONTRACTOR NAME],

This letter constitutes formal notice that the plumbing work performed at [PROPERTY ADDRESS] is defective and has caused substantial water damage to my property. The work fails to comply with the California Plumbing Code, accepted trade standards, and the scope of work specified in our contract. Pursuant to California Business and Professions Code Sections 7109 and 7110, I hereby demand immediate repair of the defective work and payment of damages as set forth below.
Contract Background
On [CONTRACT DATE], the parties entered into a contract for plumbing services (California C-36 Plumbing Contractor License No. [LICENSE NUMBER]) at [PROPERTY ADDRESS]. The scope of work included [DESCRIPTION: e.g., repair of a slab leak in the hot water supply line under the master bathroom] for a total contract price of $[CONTRACT AMOUNT]. The work was completed on [COMPLETION DATE]. I paid the full contract amount of $[AMOUNT PAID]. Copies of the contract/invoice and payment records are enclosed.
Description of Defects and Damage
On [DATE DEFECTS/LEAK DISCOVERED], I discovered that the plumbing work you performed was defective. Specifically:

Nature of Defect: [Describe: e.g., The slab leak repair failed at the joint connection, causing water to leak under the foundation. A subsequent leak detection test confirmed that your repair joint was the source of the new leak.]

Code Violations: [Describe: e.g., The repair was performed using a compression fitting on a buried line, which violates California Plumbing Code Section XXX requiring soldered or welded joints for underground copper pipe.]

Resulting Damage: The defective work caused extensive water damage including:
- [e.g., Saturation of foundation and subfloor in master bathroom and adjacent bedroom]
- [e.g., Damage to hardwood flooring requiring replacement of approximately 400 sq ft]
- [e.g., Mold growth behind baseboards and under flooring requiring professional remediation]
Legal Violations
Your conduct violates multiple provisions of California law:

1. B&P Code Section 7109 - Departure from Standards: The work departed from accepted trade standards for plumbing repair by using [describe deviation].

2. B&P Code Section 7110 - Building Code Violations: The work violates California Plumbing Code requirements, specifically CPC Section [CITE SPECIFIC SECTIONS].

3. California Plumbing Code: [Cite specific code sections violated, e.g., CPC 605.3 requiring specific joint methods for underground copper pipe]

These violations entitle me to actual damages, and in the case of willful violations, treble damages under B&P Code Section 7160 and recovery against your contractor's license bond.
Damages Calculation
As a direct and proximate result of your defective plumbing work, I have suffered the following damages:

Plumbing Repair Costs:
- Leak detection service: $[AMOUNT]
- Proper repair/reroute by licensed plumber: $[AMOUNT]

Water Damage Restoration:
- Emergency water extraction and drying: $[AMOUNT]
- Flooring removal and replacement: $[AMOUNT]
- Drywall repair and painting: $[AMOUNT]

Mold Remediation:
- Mold inspection and testing: $[AMOUNT]
- Professional mold remediation: $[AMOUNT]

Additional Damages:
- Personal property damage: $[AMOUNT]
- Temporary housing: $[AMOUNT]
- Excess water bills: $[AMOUNT]

TOTAL ACTUAL DAMAGES: $[TOTAL]
Demand and Deadline
DEMAND FOR PAYMENT

I hereby demand that within fifteen (15) days of the date of this letter, no later than [DEADLINE DATE], you pay the sum of $[TOTAL DAMAGES] representing my actual damages.

If I do not receive full payment by this deadline, I will pursue all available legal remedies including but not limited to:
- Filing a formal complaint with the Contractors State License Board seeking license suspension and restitution
- Filing a claim against your contractor's license bond ($25,000 minimum) with [BONDING COMPANY NAME]
- Filing a civil lawsuit seeking actual damages, treble damages under B&P Code 7160, attorney fees, and court costs
- Reporting the code violations to the local building department

This letter shall serve as the written notice required under California law. Govern yourself accordingly.
Closing
Sincerely,

[YOUR NAME]
[YOUR ADDRESS]
[YOUR PHONE]
[YOUR EMAIL]

Enclosures:
- Copy of plumbing contract/invoice
- Payment records
- Leak detection report
- Photographs of defective work and water damage
- Repair estimates from licensed C-36 contractors
- Water damage restoration invoices/estimates
- Mold inspection and remediation estimates

cc: Contractors State License Board
cc: [BONDING COMPANY NAME]

🚀 Next Steps

What to do after sending your demand letter.

Recommended Action Sequence

Step 1: Send Demand Letter

Send via certified mail with return receipt. Keep a copy. Allow 15-30 days for response.

Step 2: File CSLB Complaint

File online or by mail with the Contractors State License Board. Attach copy of demand letter and all documentation.

Step 3: File Bond Claim

Contact the bonding company listed on CSLB license lookup. Submit complete claim package.

Step 4: Consult Attorney / File Suit

If no resolution, consult a construction defect attorney or file in Small Claims (up to $10,000) or Superior Court.

Insurance Considerations

💡 Check Your Homeowner's Insurance

Many homeowner's policies cover sudden and accidental water damage (but typically NOT gradual leaks). Important considerations:

  • Covered: Sudden pipe burst, accidental discharge, resulting water damage
  • Often NOT Covered: Gradual leaks, maintenance issues, the plumbing repair itself
  • Subrogation: If insurance pays, they may pursue the contractor on your behalf
  • Coordination: You can pursue the contractor for your deductible and uncovered damages

Polybutylene Pipe Considerations

If your home has polybutylene (PB) pipes (gray plastic pipes with markings like "PB2110"), consider these factors:

  • Full Replacement Recommended: Spot repairs of PB systems typically fail; full replacement is the standard of care
  • Insurance Issues: Many insurers will not insure homes with known PB plumbing or will exclude PB-related claims
  • Disclosure Required: If selling, you must disclose known PB plumbing to buyers
  • Claims Against Prior Owners: If PB was not disclosed when you bought, you may have claims against the seller

Filing Options Based on Claim Amount

  1. Small Claims Court (Up to $10,000)

    Fast, inexpensive, no attorney needed. File at the courthouse in the county where the work was performed. Good for smaller plumbing repairs gone wrong.

  2. Limited Civil Court ($10,001 - $25,000)

    More formal process but still streamlined. Attorney recommended but not required. Covers many plumbing damage claims.

  3. Unlimited Civil Court (Over $25,000)

    For larger claims including extensive water damage, mold, and treble damages. Attorney strongly recommended. Full discovery available.

Need Professional Help?

Plumbing defect cases with significant water damage, mold, or slab leaks can be complex. Get a 30-minute strategy call with a construction attorney to evaluate your options.

Book Consultation - $125

California Resources