Attics

A bathroom fan vent pipe must be properly insulated to prevent condensation.  Breakdowns like this can create moisture that will travel back into the living spaces and cause damage.

Water damage on ceiling drywall isn't always due to a roof leak or insulation issues.  Sometimes the work of other trades in the attic fails and causes additional moist air that is not properly ventilated.   It's a good idea…

Any penetration to the needs to be sealed and properly vented out through the roof.  Even seemingly harmless penetrations like this built-in vacuum exhaust need to be vented outside as they are a source of warm, moist air.