Relative humidity, or RH, compares the water vapor present in air with the amount associated with saturation at the same temperature, expressed as a percentage.
What this means at your property
Because temperature affects the comparison, RH can change when air warms or cools even without adding or removing water. A room reading therefore needs temperature and context to help explain drying conditions.
Can room RH confirm a wall is dry?
No. Air conditions and moisture retained in materials are separate measurements. Ask for material readings at identified locations alongside the air measurements used to manage the drying environment.