"Water intrusion" refers to water getting into a place where it shouldn't be, such as a building or a vehicle. It can cause damage and lead to problems like leaks, mold growth, and deterioration of materials. Full definition
The buyers ordered an inspection, and the resulting report did mention evidence of water intrusion. (nar.realtor)
Water intrusion into buildings can result in mold contamination that manifests later, leading to indoor air quality problems. (cdc.gov)
Based on our survey, it appeared that a limited number of properties suffered moderate damage from water intrusion to walls and roofs and HVAC systems, while even fewer suffered permanent damage. (nic.org)