I know there is mold in this attic. But can someone help me out? Is the plywood covered with mold? Can someone tell me what this stuff is? Is it a retardant applied to the plywood? Any help would be welcome. This is a single family, 25-30 year old house. Ridge vent and soffit vents, no gable venting. The ridge vent was installed when new roof was put on, 3-6 years old. Some of the sheeting has been replaced and looks like roof vents were removed also.