High humidity inside a home might be defined as moisture damage waiting to happen. While low humidity and chronically dry conditions also have consequences, moisture damage due to high humidity is generally a more widespread problem.
Most experts recommend keeping indoor humidity levels in the range of 30% to 60%. In many locales, however, Mother Nature doesn’t cooperate with published guidelines and outdoor levels frequently exceed the recommended 60%.
Here are three ways humidity can inflict moisture damage on your home:
Toxic Mold Growth
Most dormant mold types are triggered into active growth mode once indoor humidity averages 60% or above for sustained periods. Mold growth typically first begins in dark areas with little air circulation and mold-friendly temperatures above 55 degrees. The most common areas of initial mold contamination are basements, crawl spaces, and attics.
However, mold doesn’t stay where it starts. Airborne reproductive spores rapidly spread contamination throughout the house wherever moisture exists. Moisture damage caused by growing mold affects building materials like wooden structure and drywall, and also infects insulation and carpeting. Toxic airborne spores may also cause allergic reactions and illness in susceptible persons who inhale the spores.
Paint and Wallpaper Damage
The large flat surfaces of walls inside a home are generally cooler than the air temperature inside the house. As humid indoor air contacts the cool wall surface, condensation occurs. Moisture damage, including flaking paint and peeling wallpaper, result from repeated cycles of dampness and drying. Simply repainting a wall or applying new wallpaper does not resolve the issue of humidity-related moisture damage.
Wood floors may be susceptible to irreversible moisture damage due to elevated humidity. While this process doesn’t happen rapidly, even expensive hardwood floors can be affected by long-term exposure to high indoor water vapor. As wood naturally absorbs moisture, it swells and expands. Boards in the floor and elsewhere react to pressure from this expansion and may warp, crack, or cup.