This spring, mildew has formed in the attic of my old home. We suspect a more efficient humidifier on a new furnace. The attic had been without venting. We had 5 roof vents installed. We have also replaced the roof. Now, how do we go about cleaning the mildew from the wood in the unfinished attic. Some have suggested washing it off with a bleach solution. Any and all help is welcomed.