Damp readings for plaster are crucial to determine the moisture content within the material. These readings are commonly measured using a non-invasive moisture meter to assess the presence of dampness or water damage. Acceptable damp readings vary depending on the specific type of plaster, environmental conditions, and building regulations.

### Acceptable Damp Reading Values

**Interior Plaster:**

* Gypsum plaster: 75% relative humidity (RH) or less
* Lime plaster: 85% RH or less

**Exterior Render:**

* Lime render: 90% RH or less
* Cement render: 85% RH or less

### Interpreting Damp Readings

Damp readings above these acceptable levels indicate the presence of excess moisture, which can compromise the structural integrity of the plaster or lead to mold growth. It is important to consult with a qualified professional for further assessment and to determine appropriate remedial measures.

### Factors Affecting Damp Readings

* **Environmental Conditions:** Temperature, humidity, and ventilation can influence damp readings.
* **Building Construction:** Faulty drainage, inadequate damp-proofing, and poor thermal insulation can contribute to dampness.
* **Moisture Sources:** Leaks, condensation, or rising damp can introduce moisture into plaster.