DU2: Vented Rainscreen

(1 point)

PURPOSE

Reduce potential for water intrusion through exterior wall assemblies.

CRITERIA

Create a vented rain screen behind the building facade. A vented rain screen is simply an air space between the structure and the facade that provides a means for intruding water to escape by draining down and away from the building assembly within that air gap.

To achieve proper drainage, meet the following criteria: 

• Cladding - Install furring strips to maintain a minimum of 1/4” gap or an engineered rain screen product that provides an air space between the exterior cladding and weather-resistive air barrier. The system must be integrated with flashing and be designed and installed to minimize moisture migration between the exterior cladding and the wall sheathing. The system must be open at the bottom and may optionally vented at top. Consider installing an insect barrier at vent locations. 
• Masonry - Veneer Provide a minimum 1” air space (recommend 2”) air space behind the masonry and full-head weep holes with a minimum 24” on center spacing at bottom of wall assembly.

VERIFICATION 

• Construction Documents details indicate depth of air gap for vented rain screen
• Provide photographs of vented rain screen prior to the First Site Visit if cannot be visually verified 
• Site Inspection by ECLC Technical Advisor

RESOURCES

2009 International Building Code (IBC), Section 1805.3 Waterproofing, Section 1805.4 Subsoil Drainage System www.iccsafe.org

Whole Building Design Guide www.wbdg.org/systems-specifications/building-envelope-design-guide/wall-systems/masonry-wall-systems