HouseSymptoms field intelligence
Likely causes
Failure modes and building-physics mechanisms connected to the clues that support or weaken them.
cause 60ventilation-and-airflow 8roof-envelope 7building-structure 6drain-waste-vent 5appliance-connections 4domestic-water-supply 4exterior-wall-envelope 4cooling-and-air-conditioning 3foundation-and-ground 3insulation-and-air-barrier 3site-drainage 3space-heating 3electrical-distribution 2leak 2windows-and-doors 2
cause⌁
Chimney flashing leak
Water enters at the roof-to-chimney transition.
cause⌁
Damaged roof underlay
The secondary weather layer is torn, brittle, poorly lapped or penetrated.
cause⌁
Failed roof flashing
A transition detail no longer reliably redirects water onto the drainage surface.
cause⌁
Hidden storm damage
Wind, hail or debris damages a weather layer without an obvious interior sign at first.
cause⌁
Ice-dam water backup
Meltwater is trapped behind roof-edge ice and moves beneath coverings.
cause⌁
Wind-driven rain entry
Rain is pushed through a vulnerable joint or opening that remains dry during calm vertical rain.
cause⌁
Wind-driven snow through a vent
Fine snow enters an opening and later melts inside an attic or roof space.
