What is the minimum gap required for a rain screen to function effectively?

For a rain screen to function effectively, a minimum gap of 10 mm is required. This gap is crucial because it allows for proper airflow behind the exterior cladding. Adequate airflow is essential for the evaporation of moisture that may accumulate due to condensation or rain exposure.

In the absence of sufficient space, moisture can become trapped, leading to risks such as mold growth and deterioration of building materials. The 10 mm space strikes a balance between effective drainage and ventilation, ensuring that any water that penetrates the outer layer can drain away quickly and that any moisture present can dry effectively.

This design consideration is fundamental in building science, especially in regions with significant rainfall, where the ability to manage moisture is critical to maintaining the integrity and lifespan of the structure.