Ventilated Air Space
for Stucco & Adhered Stone
Prevent Entrapped Moisture.
Reduce Cracking.
Beginning in 2018, the International Building Code (IBC) Section 2510.6 Exception 2 states that
“Where the water-resistive barrier is applied over wood-based sheathing in Climate Zone 1A, 2A or 3A, a ventilated air space shall be provided between the stucco and water-resistive barrier.”
The rule applies to adhered masonry veneer, such as manufactured stone, thin cut natural stone, and thin brick.
Creating a continuous, predictable air gap between the scratch coat and the WRB with a rainscreen drainage mat improves the ability of the wall to drain and dry. The ventilated air space drains incidental moisture and enhances the performance of the WRB by eliminating hydrostatic pressure which mitigates leaks from fastener penetrations.
Ventilated Stucco Requirements
- Predictable and continuous rainscreen drainage gap over the entire wall
- Rainscreen compatible weep screed to drain the bottom of the wall
- Ventilation at the top of the wall to increase drying potential
When detailing it’s important to think like water. Any water that enters the rainscreen drainage gap should be able to drain with gravity directly to the exterior. Any water vapor that remains in the air gap should be able to vent upwards through statck effect to the exterior.
IECC Climate Zones
IECC Climate Zones Included in climate zones 1A-3A: Florida, Georgia, South Carolina, North Carolina, Alabama, Mississippi, Louisiana, Arkansas, Oklahoma & Texas
Essential Moisture Management Components
for Stucco & Adhered Stone
