4. Wall-to-roof interface and related horizontal structures

The upper section of a straw wall is not limited to the junction between the wall and the roof structure. It also includes all horizontal or gently sloping surfaces on the facade or at the top of the wall: exterior sills, thresholds, wall copings, niches, thatched vaults, projecting elements, and rainwater drainage systems.

These structural elements are areas where moisture stress tends to concentrate. In straw bale construction, they are particularly vulnerable due to the material’s sensitivity to prolonged exposure to moisture.