1. Observe and protect
Record symptoms, prevent further damage where that's safe, and collect whatever relevant history is available.
2. Evaluate the house and site
A sound call starts by walking the system, not guessing at it: fixture symptoms, pipe material and age, pressure readings, drainage and venting paths, shutoff locations, access constraints, and any repairs already on record.
3. Define a written scope
Put preparation, protection, materials, access, permits, testing, cleanup, finish restoration, exclusions, and change-order rules in writing.
4. Compare providers
Compare credentials, then weigh the reasoning and boundaries in each proposal -- not simply the total price.
5. Inspect closeout
Confirm testing, cleanup, documentation, warranty terms, and ongoing maintenance responsibilities before signing off.