What must be done with seams in vapor retarder installations?

In vapor retarder installations, seams play a critical role in preventing moisture movement through the building envelope. The correct approach is to lap and seal these seams. Lapping involves overlapping the edges of the vapor retarder sheets to create a continuous barrier that helps minimize the passage of moisture. Sealing these overlapped seams is essential for ensuring that any potential gaps are closed off, further preventing moisture migration and enhancing the effectiveness of the vapor retarder.

This method helps maintain the integrity of the building's moisture control system, reducing the risk of condensation, mold growth, and related issues within the walls or ceilings. Properly lapped and sealed seams are crucial in achieving an efficient vapor barrier, especially in climates where moisture control is paramount for building performance and occupant comfort.