Upstairs bathroom
- Source at the fixture or supply
- Down through the ceiling cavity
- Along joists
- Wall base two rooms away
- Subfloor under flooring that still looks fine
What looks fine but isn’t: Ceiling two rooms over · Wall base below the source · Subfloor under intact flooring
Kitchen
- Dishwasher, fridge line, or sink supply
- Into the kick space and cabinet floor
- Through the subfloor
- Into the ceiling of the room below if stacked
What looks fine but isn’t: Cabinet backs that look dry · Adjacent pantry toe-kick · Ceiling below
Roof
- Penetration or valley
- Attic insulation
- Ceiling drywall
- Exterior wall cavity on the downhill side
What looks fine but isn’t: Insulation that holds water out of sight · Top plates · Windows below the leak
Basement floor
- Slab or crawl
- Up the bottom plate
- Into the first wall cavity
- Under finished flooring at the edge
What looks fine but isn’t: Bottom plates · Carpet tack strip · The 'dry' corner on the other side of the room