If left alone mold in joists can eventually become such a problem that it can only be removed by professionals.
Floor joist mold growth.
Thirty percent moisture content is saturated wood so when the joists get this wet you have a serious problem and need to be installing a crawl space encapsulation system.
Mold spores in the air.
While this is clearly an extreme case mold growth on the joists is fairly common if a home is built during the winter months.
The best course of action is always to remove any spores in the earliest stages of development so follow the simple steps below to effectively get rid of all of it.
In some cases altering the conditions around the wood can stop growth but in more severe situations a visit from a professional is required.
However something that commonly gets overlooked is your floor joists and subfloor also known as your basement ceiling.
As mentioned before all mold needs to grow is a food and moisture source.
A variety of fungi can result in mold or mildew on floor joists.
Thankfully even this level of mold growth can be addressed without replacing the joists though the amount of work required is still substantial.
Removing the problem depends on the type of fungus responsible and the degree of infestation.
Beyond that some factors that contribute to a higher chance of mold growth include.
Heavy mold growth on tji joists from new construction.