Repair, Remediation, and Safety
What this domain tests
This domain covers diagnosing failures, choosing repair scope, and working safely. Concepts: failure modes (clogged weep holes, reversed slope, breached membrane, failed curb flashing), repair scope (patch vs. partial vs. full replacement), and safety (silica dust, mortar burns, confined work, fall and electrical hazards).
Traps
- Patching a membrane breach without addressing the water that already reached the framing - hidden rot and mold.
- Assuming a leak is at the drain when the actual path is a curb fastener or a failed wall-to-pan junction.
- Re-tiling over a failed pan, which hides but does not fix the problem.
- Ignoring silica dust controls when cutting tile or mortar, or skipping PPE for alkaline mortar contact.
Rule of thumb
Diagnose before you demolish. Trace water from the drain outward and from the underside upward; the visible stain is usually downstream of the actual breach.
Worked example
A ceiling stain appears directly below a shower curb, not below the drain. Correct reasoning: the leak path is likely a curb fastener or failed curb flashing, since the stain aligns with the curb, not the drain. Repair scope includes the curb flashing, not just a drain re-seal - and the framing must be inspected for moisture damage before closing up.