It may surprise you to learn that 95% of the mould we encounter and treat is in the attic...
Everyday activities -- like taking baths and showers, doing laundry, and cooking -- create moisture in your home that rises up into your attic.
In an ideal scenario, high humidity activities that take place within your living space are vented by fans that lead to the outdoors -- bypassing the attic all together.
The remaining moisture that makes its way naturally to the attic should be vented to the outside by way of roof vents and properly installed soffit vents in the attic which are clear of all insulation and debris.
If any of these systems have not been put in place, or have degraded over time -- the balance between moisture in and moisture out breaks down. This creates the perfect environment for mould growth.