Mold & Insulation
High humidity in the crawl space has caused damage to the floor joists and insulation. Mold is present on the floor joists, and insulation is falling.
Mold Growth
The inspector pulls back a section of insulation, looking for moisture damage and mold growth. Even behind the insulation, they note mold and mildew growth on the subfloor and joists.
Measuring Relative Humidity
The relative humidity in this crawl space is reading at 70.05%. In an ideal situation, to prevent mold growth and moisture damage, we want to see humidity below 60%. For a prolonged time, high relative humidity results in moisture damage and mold & mildew growth.
Wood Moisture Content
The wood moisture content is tested in several locations throughout the crawl space. This particular joist registers at 19%, this is the point where we wood rot begin.
Water Infiltration & Joists
The advisor marks the floor joists that are affected by mold and high moisture with chalk and notes the signs of water infiltration in the crawl space. The white lines approximately halfway up the piers are an indicator of moisture and water infiltration.
Insulation & Dehumidification
On the left side of this photo, there is a thicker section; this is R-11 insulation. This insulation is required by code to protect from frost during the winter months. On the right, just past the plumbing, the dehumidifier is installed. This will regulate the relative humidity in the crawl space, only turning on when necessary.
Vapor Barrier
A vapor barrier is installed over the crawl space floor, up the foundation walls above outside grade, and around piers. The vapor barrier will help protect the crawl space from the earth's moisture in the soil and wicking through the cinderblock from outside. It's important to remember that vapor barriers do not protect from bulk water infiltration.
Mold Remediation
The floor joists are treated with an antimicrobial to kill the mold and mildew growth. There will still be some staining on the wood from the microbial growth, but as long as we control the humidity in the crawl space, we can help to prevent future mold growth. While the joists did have a high moisture content, no significant damage was noted and controlling the relative humidity should prevent future damage.
