IBC Requirements for Building Wrap
When using a building wrap as a weather-resistant barrier (WRB), it must meet 2018 International Building Codes (IBC 1402.2) requirements of a WRB for water-resistance and vapor permeability.
A superior building wrap is air- and moisture-resistant, permeable, and has a high UV-resistance and tear strength. It should also be simple and quick to install, to limit damage during application. Using a high-quality building wrap compliant with IBC 1402.2 code creates a structure with a weather-resistant exterior wall envelope. A weather-resistant exterior wall envelope ensures a building is energy-efficient and healthy.
2018 International Building Codes (IBC) mandate buildings meet minimum requirements for exterior walls. IBC Chapter 14 IBC provides these minimum requirements, including wall coverings, exterior doors and windows, exterior wall openings, and architectural trim. Specifically, section 1402.2 states exterior walls must provide a building with a weather-resistant exterior wall envelope. Exterior wall design and construction must include a water-resistant barrier behind exterior veneer preventing accumulation of moisture within wall assemblies. Exterior walls must also include a way for water/condensation entering a wall assembly to drain/evaporate.
IBC specifies a few cases where a weather-resistant exterior wall envelope is not required.
- Code does not require a weather resistant wall envelope over concrete or masonry walls designed in accordance with IBC chapters 19 and 21.
- Code does not require a weather resistant wall envelope for exterior insulation and finish systems (EIFS) in compliance with IBC 1407.4.1.
- IBC 1407.4.1 states for EIFS with drainage, water-resistive barrier must comply with IBC Section 1403.2 or ASTM E2570. IBC 1403.2 states attachment of no fewer than one layer of No. 15 asphalt to studs or sheathing, with flashing, must provide a continuous water-resistive barrier behind exterior wall.
- Exterior wall envelopes resisting wind-driven rain, including openings, joints, and intersections with a dissimilar material in accordance with ASTM E331 are not required to have a weather-resistant exterior wall envelope.
BENEFITS OF BUILDING WRAP
Applying a high-quality building wrap, like Barricade® Building Wrap, over sheathing, and behind siding, meets or exceeds IBC 1402.2 requirements for weather-resistant barriers. A properly installed building wrap creates a protective envelope against air infiltration and moisture into wall systems. A buildup of moisture within a building’s walls is problematic because moisture can lead to wood rot (caused by fungi) and expensive repairs. High moisture can also cause mold, unhealthy for structure occupants. Uncontrolled air infiltration lowers effective wall system R-value and lessens energy-efficiency and air quality of a building. To reduce air infiltration and stop accumulation of moisture within wall systems, along with meeting requirements of IBC 1402.2, design of a high-performing exterior wall must include a weather-resistive barrier, like building wrap.
