Molds can grow on virtually any substance, as long as moisture or water, oxygen, and an organic source are present. Molds reproduce by creating tiny spores (seeds) that usually cannot be seen without magnification. Mold spores continually float through the indoor and outdoor air. When excessive moisture or water accumulates indoors, mold growth often will occur. Molds gradually damage building materials and furnishings. If left unchecked, mold can eventually cause structural damage to a wood framed building, weakening floors and walls as it feeds on moist wooden structures. Molds may cause adverse health concerns which is why it is important to remediate (remedy) it quickly.
Penicillium (fungus common in house dust) and Stachybotrys (black mold that can be poisonous) growing in a wall cavity, after water leaks. Penicillium requires less moisture and cooler temperatures to grow.
Stachybotrys is a black or greenish black slimy mold
associated with prolonged water damage as shown here.
Yellow Cladosporium (Clados or Klados mean sprout/branch) mold can be found anywhere indoors, including on textiles, bathroom tiles, wood, moist windowsills and any wet areas in a home. Here it is in a wall cavity with insulation.
Stachybotrys and aspergillus mold growing from a leak in an indoor water heater station. Aspergillus (aspergere means sprinkle) are commonly found in water damaged environments and can produce toxins and should be dealt with using extreme caution.