Protection from weather in walls is accomplished in one of two ways: the drainage wall and the barrier wall. The two types are illustrated. The barrier wall attempts to stop all rain at the face, but is nearly impossible to build; problems occur at openings, where water can become trapped behind the barrier. The drainage wall is more practical and successful; it is the best wall for resisting wind-driven rain, it breathes, and it can be built quite easily. Precautions that can be taken to reduce the small amount of water penetration through drainage walls still further are outlined. They include: the use of full-head joints; tooling mortar joints with a steel jointer; cleaning the cavity in construction; using water-resistant sheathing and building paper; and incorporating through-wall flashing and weep holes.