What should be done to properly drain water within a drainage wall system?

To properly drain water within a drainage wall system, it is essential to install an open drainage plane. This approach facilitates the movement of water away from the wall assembly, preventing moisture accumulation that could lead to structural issues or damage over time. An open drainage plane allows for gravity drainage and enhances the overall effectiveness of the drainage system by providing a pathway for water to escape efficiently.

In this context, the other options do not effectively contribute to the drainage needs of a drainage wall system. Creating an air seal may help in preventing air leaks but does not assist in managing water. A moisture barrier can impede the passage of water, which could cause trapped moisture behind the barrier and lead to potential damage. Increasing wall thickness might provide some structural benefits but does not address the critical aspect of water drainage and could potentially exacerbate issues related to moisture retention if not designed for drainage purposes. Therefore, the installation of an open drainage plane is the most effective method for ensuring proper water drainage within a drainage wall system.