Preventable damage is damage that occur over time and can be avoided by pre-emptive action. This can be a large Douglas-fir or Hemlock tree root slowly growing under or through your foundation, or raccoons living in your attic. So when you see the risk of pest damage in advance and take action to prevent the damage but if you don’t do anything then your insurance companies will likely deny coverage. Unexpected damage is when a homeowner performing reasonable maintenance doesn’t anticipate the damage. For example, damage from a storm allows pests to enter your home and cause damage, this would qualify but not if combined with preventable pest damage. If rats get into your attic and cause all kinds of damage, your insurance wont cover that damage but it will cover fire damage caused by a rat chewing threw fire causing said fire.
https://gogreenpestcontrol.ca/pests-and-home-i…nexpected-damage/
https://www.linkedin.com/pulse/pests-home-insurance-preventable-unexpected-damage-randy-bilesky/?published=t