Foundation Walls and Open Vents
The foundation walls of this crawl space are covered in efflorescence, a clear indicator of moisture infiltration. This occurs when water from the outside seeps through the porous cinderblock walls and pulls all the salts and sediments to the surface. Open vents lining the foundation walls allow outside air and moisture to freely enter the crawl space and affect not only the relative humidity in the crawl space but also the air quality inside your home.
Vapor Barriers and Dirt Floors
The floor of this crawl space is littered with ladders, debris, fiberglass insulation, and a flimsy 6-mil vapor barrier. This liner, which is supposed to cover the dirt floor and protect the crawl space from the Earth's moisture, has many rips and tears in it and has been shoved away from its original position, exposing the dirt floor. This allows the moisture rising from the Earth to affect the crawl space by increasing the relative humidity of the area and creating the perfect dark and damp environment that pests and critters love.
Fiberglass Insulation
The fiberglass insulation in this crawl space is sagging and falling to the dirt floor in large chunks. This is a major indication of excessive moisture within the crawl space. The fiberglass acts much like a sponge, absorbing the moisture in the crawl space air. This tells us that the relative humidity is too high and needs to be controlled. When the relative humidity becomes too high, the water droplets pull apart the fine glass fibers of the insulation, and the weight of all the excess moisture causes the fiberglass to become too heavy to sit in place between the floor joists.
Mold and Mildew
Mold and mildew have begun to grow on the floor joists of this crawl space. This occurs when the relative humidity is above 60% with warmer temperatures in the crawl space and can grow on any of the organic materials within. The homeowners can smell a musty odor in their home, and those mold spores that do find their way into the home above can affect the inhabitants by irritating those with allergies or asthma.
