Mold and fungus is caused by areas where the relative humidity exceeds 60%. Please understand this, if you have existing mold and fungus in the crawl space and you keep the crawl space humidity under 60% all the time then the existing mold and fungus will go into a dormant stage. Once it is in dormant stage, there is no longer any new mold spore production and the wood framing will stop rotting. But, the wood framing will look the same.
This could be a problem when you go to sell your home in the future and you have "dormant" mold and fungus on the wood framing. Home inspectors will still take pictures of mold and fungus, dormant or not.
WHAT ARE MY REPAIR OPTIONS TO REMOVE EXISTING MOLD?
1) Soda Blasting. Soda blasting is like sand blasting but you are using baking soda instead of sand. It will physically remove the mold and fungus off the surface of the wood framing. It will not remove the roots in the wood or remove any mold stains so often times the wood looks the same. Soda blasting under a crawl space releases a tremendous amount of dust particles in the air as the soda is being blasted into thousands of pieces. This soda dust will make it's way upstairs. It is completely unavoidable to not have soda dust particles upstairs after soda blasting in a crawl space so expect a clean up job by yourself after it's done. Soda blasting is also an expensive process. Soda blasting costs usually range from $2.50 a sq ft to $3 a sq ft.
2) Sanding or HEPA Vacuuming. This is the slowest and most time consuming process available. There is an incredible amount of labor involved with sanding or vacuuming by hand every square inch of wood framing in a crawl space. This will remove mold and fungal growth on the surface.
3) Mold Spray Treatments. Spray treatments do not remove mold and fungus. They just disinfect it only. Many times the wood framing looks the same after just a spray treatment.
4) Mold Spray Treatments With Physical Scrubbing. This method will kill the mold and fungus and physically remove the growth as well. This method has far less dust being released in the air compared to soda blasting. This method will kill and disinfect mold, and physically remove mold.