One of the most frequent code violations we uncover during DFW attic extractions is the disconnected bathroom exhaust fan. The builder installed the fan in the bathroom ceiling, but simply laid the flexible exhaust tube down on top of the attic fiberglass, pointing it at a soffit vent, instead of physically cutting a hole through the roof deck.
The Daily Steam Injection
Every time you take a hot, 15-minute shower, the exhaust fan pulls massive amounts of 90°F, 100% humid steam out of the bathroom. If that tube ends inside the attic, you are literally dumping gallons of vaporized water directly onto the wood roof decking and paper-backed insulation underneath.
Over 3 years, that daily localized steam injection rots the plywood roof deck from the inside out and cultivates a massive, localized bloom of black mold directly over the master bathroom.
The flexible duct must be mechanically attached to a dedicated, flappered roof vent. The steam must physically exit the house through the shingles into the outside atmosphere. A professional insulation team fixes this routing before pouring new fiberglass.