In this video, This Old House general contractor Tom Silva shows a professional approach to eliminating dangerous fungus outbreaks.
1. Cover attic floor with sheets of polyethylene.
2. Set up a negative air machine to filter the air while cleaning the moldy surfaces.
3. Use dry-ice pellet gun to blast the mold from the rafters and underside of the plywood roof sheathing.
4. Vacuum the mold dust from the polyethylene sheeting using a vacuum equipped with HEPA filter. Then, carefully remove and discard the sheeting.
5. Spray or brush a mold-inhibiting coating to all rafters and plywood sheathing.