Diagnose a Ceiling Leak. It's Never Where It Drips (en Inglés) - Jason Stewart Hammond;Jason Stewart Hammond

Water travels. It runs along the top of a ceiling joist, across a rafter bay, down the face of a duct - and shows up as a drip, a stain, or a bulge in the ceiling somewhere that isn't directly below the source. Homeowners who cut drywall open at the visible stain almost always find nothing. The real leak is three feet away, ten feet away, or in a different room entirely.

This book walks the diagnostic method that finds the actual source:

probability.

contain damage, kill electrical if needed.

apart before you open the ceiling.

Written for the homeowner who'd rather spend an hour diagnosing than spend the afternoon patching a hole that didn't solve the problem.