The best measure of moisture in a building is relative humidity (RH). RH is a measure of the amount of water vapor in the air compared to the amount of water vapor the air can hold at a given temperature. RH is typically expressed as a percentage.
RH is the best measure of moisture because it is a direct measure of the amount of water vapor in the air. Other measures of moisture, such as dew point and wet-bulb temperature, are indirect measures of moisture and can be affected by factors such as temperature and air pressure. RH is not affected by these factors and is, therefore, a more reliable measure of moisture.
The ideal RH for most building materials is between 30% and 50%. At this RH, the materials will not be damaged by moisture or mold growth. RH levels that are too high or too low can cause problems. High RH levels can lead to condensation and mold growth. Low RH levels can cause wood and other materials to dry out and crack.
There are several ways to maintain the ideal RH in your building. These include:
If you suspect that your building has water damage, you should look for the following signs:
If you see any of these signs, you should contact a professional to determine the extent of the water damage and to repair the damage.