We see mould growth in attics if there are not enough vents installed. Check your local building codes for what is required in your area, but in general, 1 square foot of ventilation is required for every 100 square feet of attic.

Any proper building inspector will check the ventilation system in a home’s attic. To pass an inspection and to ensure that an attic stays cool and dry, make sure there is an appropriate system in place that is unlocked by the insulation.

Knowing the appropriate signs of mold in the attic, and how to prevent them in the first place, can save you a major headache when selling your home.

Incorrect evacuation of bathroom fans or dryer vents

Dryer vents, kitchen extraction fans and bathroom extraction fans are designed to remove moisture from your home. So make sure they end outside your home and NEVER in the attic. Plumbing chimneys in the attic can also be a source of condensation, which can lead to mold growth in the attic. Plumbing chimneys can also emit hazardous gases, so make sure they don’t end inside the attic either.

Roof problems/leaks

Roof leaks often lead to a small localized area of attic mold near where the leak occurs. Below are some ways to check for possible roof leaks:

• Check the discoloration/dark spot areas of the wood (e.g. Chevrons, cladding, joists, attic side of the shore planks, etc.).
  
• Check the roof valleys (i.e. where two roofs meet at an angle), which are very sensitive to roof leaks.
  
• Observe vents, plumbing chimneys, chimneys, attic windows and any part of the attic/roof where different materials meet (including seess). These areas are hotbeds of potential moisture intrusion.

How to get rid of a mold problem in the attic

In addition to solving the moisture problem causing the mold problem, you also need to get rid of the mold properly.

To do this, there are three options:

• Remove mold from the attic yourself (do-it-yourself)
  
• Solve only moisture problems, but leave the attic mold
  
• Professional treatment of mould in attics