1. Observe and protect
Start by writing down what you're seeing, when it started, and anything you've already tried, and address anything that's actively getting worse.
2. Evaluate the house and site
A provider should look at what's actually behind the wall or under the floor — drain location, framing condition, ventilation, and electrical capacity — before proposing a fix.
3. Define a written scope
Get the prep, materials, permits, testing, cleanup, exclusions, and change-order process in writing, not just a total number.
4. Compare providers
Line up two or three proposals side by side and compare the reasoning behind them, not just which one is cheapest.
5. Inspect closeout
Before calling it done, confirm testing results, a clean job site, any warranty paperwork, and what maintenance falls on you going forward.