During a routine inspection, you notice a small, dark stain on the ceiling below a second-floor bathroom. There are no visible drips. What is the most appropriate first step to identify the source of this potential leak?

Question: During a routine inspection, you notice a small, dark stain on the ceiling below a second-floor bathroom. There are no visible drips. What is the most appropriate first step to identify the source of this potential leak?

Answer options:

• Immediately open up the ceiling to expose pipes
• Pressure test the entire house's water supply system ✅ Inspect the toilet, shower, and sink connections and seals in the bathroom above
• Apply a strong biocide to the stain to prevent mould growth

Correct answer: Inspect the toilet, shower, and sink connections and seals in the bathroom above

Explanation: The most appropriate first step is to methodically inspect all plumbing fixtures and their connections in the bathroom directly above the stain, as many leaks originate from faulty seals or connections that may not be immediately obvious. Opening the ceiling is premature, pressure testing is too broad at this stage, and biocide doesn't address the leak source.