attic moisture. Even small gaps around the hatch can allow massive amounts of warm, heated indoor air to fill the attic space and trigger condensation during winter. The water on your roof sheathing probably wafted off a pot of boiling pasta you ate a couple of days ago, or billowed out of the shower last week.

When you’ve done everything you can to make sure that indoor air never gets to the attic, it’s time to boost ventilation. Wooden soffits are notoriously difficult to ventilate well. You really need to have a continuous, louvered opening along the entire length of all eaves.