This is blue stain mold or blue rot and is nowhere near the same thing as Stachybotrys atra, the frightening toxic black mold, seen on the news. Ceratocystis does not rot the wood, is not harmful to human beings, and does not spread.

The following is a simple guide on how to remove this cosmetic mold from smooth wooden surfaces. If some of the wood framing in your home has been contaminated by Ceratocystis mold, then it can be possible to clean these and remove the mold contamination in some cases.

If the contaminated wood is located on the exterior, you can use more violent methods of cleanup such as power-washing or sandblasting, but this is not recommended for use indoors. Spreading mold spores and debris throughout the house is a problem when these powered methods are used inside the house.

The best thing for removing surface mold from framing lumber is to use a sponge that has been wet with a mixture of water and borax laundry detergent. This is not to produce a completely particle-free wooden surface, but only to remove all of the surface mold. Do not use a sponge in one area and then use the same sponge in another, because of the risks of cross-contamination. Five tablespoons of trisodium phosphate mixed in a gallon of water can be used to clean up mold stains after any loose particles have been removed.

Sanding mold off of a surface is an option as long as the mold is a cosmetic one and the initial cause of the mold's growth has been removed. High humidity indoors or leaks inside the house can restart this growth, so make sure that these issues have been resolved before attempting to sand away a cosmetic mold. A spraying method may be better than a sanding method of removal for large areas.

Before you treat the areas you have cleaned any further, the surface needs to be completely dry and the cause of the mold growth removed, in the case that the mold was not on the lumber at the time of construction.

Mold-resistant varnishes are available and have some advantages and disadvantages. Something good about sealants is that using them after a remediation project can immobilize the particles left inside some hard to reach cracks and crevices in the wood and stop them from re-growing and they will most likely reduce how much moisture the wood absorbs in the future. These sealants and sprays are never to be used as a substitute for thoroughly removing the mold, however.