Unit-to-unit leak tracing is one of the most common—and most contentious—challenges in condo and apartment living. When water from one unit damages another, determining the exact source and pathway is essential for resolving liability, processing insurance claims, and preventing further damage. CondoLeak.ca specializes in precise, non-destructive leak tracing between residential units throughout BC.
Why Unit-to-Unit Leaks Are Complex
Water doesn't always travel in straight lines. In multi-unit buildings, water can migrate along floor joists, through wall cavities, around plumbing penetrations, and across multiple units before appearing as visible damage. A ceiling leak in Unit 301 might actually originate from a plumbing failure in Unit 401 or even a building envelope defect on the exterior.
This complexity creates several challenges:
- Determining which unit owner is responsible for repairs and damages
- Coordinating access to multiple units for investigation
- Managing neighbor disputes and insurance complications
- Distinguishing between unit owner and strata corporation responsibility
Common Unit-to-Unit Leak Scenarios
Bathroom and Kitchen Failures
Toilet wax ring failures, shower pan leaks, bathtub overflow events, dishwasher supply line failures, and under-sink plumbing leaks are frequent causes of ceiling damage in the unit below.
Our Approach: We use moisture meters and thermal imaging to trace water pathways from ceiling stains back to the precise fixture or connection failure in the unit above.
Washing Machine and Appliance Leaks
Failed washing machine hoses, dishwasher overflows, refrigerator water line leaks, and hot water tank failures can release significant volumes of water that migrate to lower units.
Our Approach: We investigate appliance connections, drainage systems, and floor assembly penetrations to determine if leaks resulted from appliance failure, installation defects, or user error.
Shower and Bathtub Waterproofing Failures
Improperly waterproofed shower enclosures allow water to penetrate floor assemblies during regular use. These slow, chronic leaks often go undetected until significant damage accumulates in the unit below.
Our Approach: Flood testing and moisture mapping identify membrane failures, missing waterproofing, or improper installation that allows water penetration.
Vertical Pipe Failures Within Units
Supply pipes and drainage stacks that run vertically through multiple units can develop leaks at any connection point. Determining which section of pipe failed—and which unit it serves—establishes repair responsibility.
Our Approach: Acoustic leak detection and pressure testing protocols identify leak locations within vertical pipe chases without extensive demolition.
Our Unit-to-Unit Investigation Process
Step 1: Document the Affected Unit
We begin by thoroughly documenting the water damage location, extent, and patterns in the affected unit. Moisture readings and thermal imaging establish the current state and help identify the general direction of water travel.
Step 2: Investigate Potential Source Units
Working with property management and owners, we access units directly above and adjacent to the damage area. We inspect plumbing fixtures, appliances, floor assemblies, and any areas where water could originate or pass through.
Step 3: Conduct Non-Destructive Testing
Using thermal cameras, moisture meters, acoustic equipment, and when appropriate, tracer dyes or smoke testing, we trace water pathways to their origin without unnecessary demolition.
Step 4: Deliver Clear Documentation
Our reports clearly identify the leak source, the pathway water traveled, and the responsible party. This documentation supports insurance claims, repair contractor scoping, and resolution of disputes between owners.
Resolving Liability and Responsibility
One of the primary reasons for professional leak tracing is to establish clear liability. BC strata property legislation and individual unit insurance policies have specific provisions regarding responsibility for leak damage.
- Unit Owner Responsible: When leaks originate from fixtures, appliances, or building components within a unit's boundaries
- Strata Corporation Responsible: When leaks originate from common property infrastructure like risers or building envelope failures
- Shared Responsibility: Complex scenarios where multiple factors contribute to water intrusion
Our investigations provide the technical evidence needed for insurance adjusters, strata councils, and legal representatives to determine appropriate responsibility and cost allocation.
When to Request Unit-to-Unit Leak Tracing
- Ceiling water stains or active dripping from above
- Musty odors or visible mold growth suggesting hidden moisture
- Disputes between neighbors regarding leak responsibility
- Insurance adjuster requests for third-party verification
- Recurring leaks where previous repairs have failed to solve the problem