Forensic water intrusion diagnosis
How a leak is reasoned to its cause: the four components of a leak, what each standard covers, a documented sequence with a worked rainfall and joint count, and a conclusion that states its evidence and its limits.
4 lessons · about 41 min · 13 diagrams · 5 videos
Version 1.0.0
Builds on these modules
Lessons
0 of 4 complete
Lesson 1 · 11 min · 12 slides · 7 questions
Forensic water intrusion diagnosis: principles and terminology
Why diagnosis is a method; the four components of a leak; the forces that move rain; why a stain is not the entry point; when the water is condensation; the three D's of rain control; and the safety limits before anyone looks.
You will be able to: Name the four components of a leak and the three conditions and four forces behind rain penetration, separate the place water shows from the place it enters, and say what AFS contributes to an investigation and what it does not.
Not startedStart →Lesson 2 · 11 min · 12 slides · 8 questions
Forensic water intrusion diagnosis: materials, standards and design constraints
What each standard says it covers and where it stops; how much of a roof each survey method sees; why lapped joints and splice plates matter; gap widths from AFS, Drexel and BSC; and the moisture thresholds for wood.
You will be able to: Choose a candidate method from its stated scope, tell guides from test methods and practices, recognize that no scope read here names roof-edge metal, and use sourced numbers for joints, gaps and wood moisture.
Not startedStart →Lesson 3 · 9 min · 12 slides · 5 questions
Forensic water intrusion diagnosis: methods and worked application
The step-by-step sequence; finding the roof point; the hypothesis table; checking a reported storm against NOAA depths; counting joints on a metal run; one-component water checks; non-destructive methods first; and what to record.
You will be able to: Apply a documented sequence to a realistic leak: locate the roof point from an interior stain, list candidates with a test that could disprove each, check the reported storm against NOAA depths, count the joints on a run, and record assumptions, units and evidence.
Not startedStart →Lesson 4 · 10 min · 12 slides · 6 questions
Forensic water intrusion diagnosis: defects, verification and case study
Six sheet-metal entry mechanisms from the Failure Atlas and the cited guides; a constructed case walked through the method; retesting; corrections with the warranty first; the leak that was not a leak; and a conclusion that can be defended.
You will be able to: Diagnose a plausible sheet-metal-related entry mechanism from its evidence, explain correction options with the warranty first, verify by retesting the same way, and write a conclusion that states its evidence and its limits.
Not startedStart →
Practical task
Produce a forensic water intrusion job packet for a constructed parapet coping run with an interior stain: choose your own measurements or use the worked examples, locate the roof point, build a hypothesis table, check the reported rain against the NOAA depths, count the joints, and write a conclusion with its limits.
Hand in
- A one-page decision rationale: what was reported, whether a warranty applies, who is contacted first, and who sets any water check.
- A marked-up sketch or plan showing the reference point, the measured distances in inches, the roof point and the neighboring elements to inspect.
- A hypothesis table: each candidate entry point with the test that could disprove it, and the result recorded for each.
- A rain check: the reported depths converted to inches per hour, compared with the NOAA depths for the same durations, with the stated cautions.
- A joint count for the run from piece length, with one table row per joint, and a statement that a real job takes the count from the layout drawing.
- A conclusion naming the most probable entry, the evidence, the alternatives ruled out, what was not tested and the limits, plus a retest plan.
Rubric
| Criterion | Meets the standard when |
|---|---|
| Symptom and entry point | The packet measures from a stated reference point, keeps the stain and the entry point separate, and lists the neighboring elements. |
| Hypotheses with tests | Every candidate has a test that could disprove it and a recorded result; no candidate rests on the stain alone. |
| Arithmetic and units | The rain conversion and joint count show their working with units, and the scenario inputs are labelled as assumptions. |
| Method limits | The packet says who sets the water rate, duration and pass criterion, uses no number the course did not source, and does not treat condensation as a leak. |
| Records and evidence | Date, weather, locations, photographs, measurements in inches, samples and anything disturbed are recorded, with a note to ask counsel about evidence. |
| Conclusion and safety | The conclusion states evidence and limits without overstating, names the fall protection plan and the two-person rule, and checks the warranty before any repair. |