Wood is highly porous and can absorb up to 30% of its weight in water weight when saturated. This makes wood ideal for fungal growth at high humidity
Dust mites feast on shed human skin and animal dander. The density of dust mites is 8-10 times higher at RH 70% than at RH 50%! Dust mites cannot reproduce at RH < 50%.
Silverfish love items containing cellulose such as glue or bindings in books. They can also ingest fabrics like cotton or wool. They love high humidity environments and often hide in cracks during the day.
Leather easily absorbs moisture from the air, even more than wood! At high humidity leather is very susceptible to mold growth. Always thoroughly clean the leather before putting away for long term storage.
Musty odor is from volatile gases emitted by certain types of mold. It is a sure and early sign of mold infestations.
Mold and water stains can occur on walls or carpets. It often means you have external sources of moisture leaking in.
Excess moisture can gather along corners of windows. This creates a perfect breeding ground for mold.
Silverfish, mold, dust mite & mildew infestations are known to cause misery to many allergy-sufferers.
Excessive humidity can weaken the adhesive and cause wallpaper to start peeling, especially at the corners.
Many mold species love cellulose - primary component of wood. At high humidity wood is very susceptible to mold.