Designing Better Masonry Envelopes Starts with the Air BarrierWords: Aric Hutchinson, Architectural Representative, Hohmann & BarnardPhotos: Hohmann & BarnardAs expectations for building performance continue to rise, air barriers have become a critical part of modern wall design. Today’s building envelopes must support energy efficiency, occupant comfort, durability, moisture management, and increasingly stringent code requirements. Airtightness plays a major role: air leakage reduces insulation effectiveness, increases HVAC demand, and contributes to moisture migration. A properly selected and detailed air barrier limits that movement while supporting the wall’s overall moisture-management strategy.Start With the Building's Performance GoalsThere is no single air barrier solution ideal for every project. Selection should begin with a basic question: What is the building expected to accomplish? Some projects prioritize exceptional airtightness and energy efficiency; others emphasize weather resistance, construction speed, or budget. Project conditions also matter, including allowable exposure time, compatibility with adjacent materials, and the substrate and environmental conditions during installation. Several technologies are available: fluid-applied systems, self-adhered membranes, and mechanically attached building wraps, each with different preparation and application requirements. The right choice depends on the membrane and how it integrates with the full wall assembly.Masonry Adds Another Layer of ComplexityFor masonry wall systems, air barrier performance cannot be evaluated independently from the anchorage system. Every masonry anchor penetrates the continuous air barrier, and a large commercial facade can contain thousands of these penetrations, each representing a potential pathway for air or water infiltration. Anchors and air barriers must be treated as one system, with the design team evaluating membrane response around fasteners, installation sequencing, and material compatibility.Continuity Depends on the DetailsContinuity is equally critical at windows, control joints, flashing interfaces, roof transitions, service penetrations, and shelf angles. Even a high-performing membrane can fall short when these transitions are not carefully coordinated. Construction sequencing matters, too: decisions made by one trade affect those that follow. Early coordination among architects, engineers, enclosure consultants, masonry contractors, and manufacturers helps identify conflicts before materials arrive on site.Design the Wall as a SystemThe strongest enclosure designs consider the air barrier alongside insulation, flashing, drainage, masonry anchorage, structural backup, and exterior cladding. Compatibility, sequencing, and installation details should be evaluated early rather than addressed after construction begins.Specifying an air barrier is ultimately a building-performance decision. When a project starts with clear goals, accounts for the unique demands of masonry construction, and maintains continuity at every penetration and transition, the air barrier can perform as intended, helping the envelope endure.About: Building Solutions
