A damp patch, condensation and a high hygrometer reading are different observations. Record each separately so that one number does not become the whole diagnosis.
| Observation | Record | Next investigation |
|---|---|---|
| Water after rain | Location, timing and photographs | Rain entry |
| Droplets on surfaces | Weather and surface location | Temperature changes |
| Damp beneath items | Material and floor location | Floor and stored objects |
| High relative humidity | Temperature, meter position and time | Repeat under comparable conditions |
Keep a garage diary
Use a consistent meter position away from direct appliance airflow. Record separate spot checks where useful. Note whether a wet car arrived, the door stayed open or rain entered. This is an investigation record, not a corrosion forecast.
There is no single humidity number here that guarantees protection. Local conditions, meter accuracy and vehicle condition limit what a room reading can tell you.
Choose the next step
Investigate obvious water entry first. Read dehumidifier selection and use the humidity tool to compare equipment with your conditions. Meaco's garage guidance explains temperature considerations for its range.
Do not block designed ventilation or alter a space with combustion appliances without qualified advice.
Sources
- MEACO — checked 25 October 2026.
Sources & checks
Checked 2026-10-25. Read the original instructions before acting.