There are some types of fungus that can become destructive to wood used in the building of structures. Brown rot, white pocket rot, water-conducting fungus (Poria incrassata) are all examples of fungi that can attack and destroy wood. In order for these fungi to develop, there must be an elevated moisture condition in an area that will not or cannot be dried out naturally. Crawlspaces in homes are one of the most common areas where these fungi may develop, especially where water is allowed to collect or where water drain pipes or water supply lines leak. If water is allowed to get onto wood members such as floor joists or floor sheathing, fungus can develop very quickly and over large areas. Controlling water leaks or infiltration of water such as rain into a structure, especially around windows, doors, gutters, and roof vent pipes is the best way to prevent wood-decaying fungi from developing. If already present, correcting the cause of the water problem must be accomplished along with an appropriate treatment for the control of the fungi. Direct application of a liquid fungicide such as borates to the fungi and wood members, will help stop and prevent any further or future damage in the treated area.