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Attic Mold

My attic sheathing is black with mold. Do I need a new roof or what should I do?

It depends on how extensive the mold is, and sometimes on what you are willing to pay for. Often times the mold is just in a few areas, requiring limited material replacement, or just cleaning. Obviously, any roof leaks, shingle flashing or ventilation issues must be fixed to prevent future mold growth. Attic mold can:

  • Worsen and become more expensive to remove if left unchecked
  • Can lower property value
  • Spread to the living areas below if left untreated
  • Contaminate belongings stored in the attic
  • Delay or cause the loss of a house sale

If there is mold growth on roof materials, can the cold weather kill it?

Generally, if conditions are favorable for mold to have grown in the attic and the mold is still alive, cold winter temperatures will slow or stop the mold from growing. However, molds produce spores with resilient outer coatings that allow them to remain alive through harsh conditions including long dry spells and cold temperatures. Thus, when the attic warms up again and sufficient moisture is present mold growth will resume. This cycle will continue until the mold has been removed and favorable growth conditions eliminated. Simply resolving the moisture issue, most often inadequate ventilation, will not kill the mold. The complete process must include two steps:

  • Identify and fix moisture/ventilation problem(s)
  • Remove mold appropriately

If the relative humidity is high enough, the roof sheeting can be damaged. The solution is the complete replacement of the roof – roof sheeting and shingles