What should be done when different wall covering materials meet?

When different wall covering materials meet, it is important to install wall penetration flashing to manage moisture and potential water infiltration. This practice is essential because different materials can expand and contract at different rates, leading to gaps or cracks that could allow water to enter the building structure. The installation of flashing creates a barrier that directs water away from seams and joints, thereby protecting the integrity of the building materials and preventing issues such as mold, rot, or structural damage.

Choosing not to install flashing, or relying only on paint, could leave the seams vulnerable to moisture intrusion. Leaving a gap for ventilation might seem beneficial in some contexts, but it does not address the need for a proper waterproofing solution at the junction of different materials. Using unstable materials would compromise the durability and resilience of the assembly and is not advisable in any construction or renovation scenario.