HIP has -- through rigourous research and development; testing and long-term monitoring -- designed a treatment specifically to treat mould on porous building materials (wood, insulation, particle board, and the like) and non-porous building materials. We have been using this process for 9 years now in the Greater Toronto Area and West (GTA, Mississauga, Oakville, Burlington, Guelph, Kitchener-Waterloo, Hamilton and further afield upon request) and have the only process that home inspectors, realtors, and property owners all feel confident recommending. HIP's propietary / patent-pending treatment protocol allows for a 1-day treatment, virtually no disruption of existing materials, mitigation of the environment that allowed for the mould to proliferate, and a guarantee that the mould and its spores are gone and are not coming back. It is people, pet and environment -friendly.
Thoroughly kills mould and its spores, addresses the cause, and completely removes visible mould residue ("mould staining")
The temporary encapsulator category of mould treatment includes Concrobium, HD's Mould Control, Benefect, Mouldoff. Each are designed to prevent mould growth; not to treat existing mould, yet routinely get used in treatment. Concrobium is principally 1.19% trisodium phosphate and water, with the TSP leaving a fine film over the mould which slows it's growth temporarily. Instructions indicate re-application after dampening or disturbance of the film and after 3 - 4 months regardless. Benefect is principally ~3% thyme oil, a topical anti-fungal treatment for athlete’s foot. The mould is shown to continue it's growth cycle post-treatment with temporary encapsulation treatment protocols.
Mildew resistant paints are designed to be applied to clean, dry, mould-free surfaces in areas prone to moisture accumulation: to prevent mould growth. They are not designed to treat existing mould, and actually make effective mould remediation exceedingly complicated once applied. If Zinsser, Kilz or RX are applied directly to mouldy surfaces, they will peel within 6 months and be dropping off in ribbons within 12-18 months.Dr. Jim Pearson on Air Quality and Mould Symptoms: "You don't cover it up. You don't paint it over."
Mildew Resistant Paints i.e., Zinsser, Kilz, and RX.
While blasting techniques were designed for high pressure industrial cleaning (of printing presses, foundries, packaging equipment, etc...), they have recently been experimented with as attic mould treatments. The process does dislodge a lot of the mould; it does not however remove all thus allowing for repopulation + the dislodged mould gets blown around and can be pushed down into wall cavities. With blasting, insulation must be replaced as the use of tarps is neither thorough nor practical due to attic construction. Often the cost of insulation replacement is presented after the initial blasting treatment making for an unpleasant surprise. Note, this is a multiple visit process that is high profile: air compressor on front lawn is loud enough to require ear protection.
Mould is dislodged from the sheathing surface; not killed.
Dry Ice Blasting and Soda Ash Blasting are used to High-Pressure Dislodge Mould
Replacing the Roof
While roof replacement does address mould on attic sheathing, it does not address mould on the rafters or the insulation: this remaining rafter and insulation mould will recolonize the new sheathing material in short order.
This process is the most expensive option for handling mould which can create the illusion that it is the most effective. It is unnecessarily inconvenient and invasive plus provides no mould-free assurance.
Involves tearing off and replacing the shingles and the plywood/OSB sheathing with new material
Scrubbing with Bleach
Because attic sheathing is rough and porous, even repeated liberal applications of bleach followed by vigorous scrubbing will only remove some of the surface mould and leave visible signs of mould after bleach has dried. The residual mould and associated spores will re-populate the orginally affected area.
Bleach can be used to clean smooth surfaces of mould.