Follow the water path, not just the stain
Water may move along decking, framing or underlayment before it appears on drywall. A stain near an exterior wall can involve roof edges, flashing, gutters or another transition. Record the room, location and time the stain appears rather than guessing at the repair.
A professional inspection should check the roof covering and the junctions around vents, plumbing stacks, chimneys and walls. Interior moisture should also be assessed to determine whether drying is needed.
Make a useful observation log
Note whether dripping happens in calm rain, heavy rain or only when the wind blows from a particular direction. Photograph the same spot on successive days for comparison. Note unusual odors, bubbling paint and changes in attic insulation.
Do not cut into electrical wiring areas, remove structural materials or enter an attic that has visible sagging or unsafe access. A small visible stain can conceal a larger moisture path.
Questions for a contractor
Ask where water is likely entering, what supports that conclusion, whether the proposed repair includes flashing and underlayment, and what happens if the leak persists. Request details in writing.
Treat a same-day verbal assurance as preliminary until you have a scope, terms and information about warranties.
Sources and official guidance
Links checked for the November 2026 editorial draft. Verify rules again before beginning work.