What are the key elements of air barrier interface at window frames?
Know the appropriate air-vapor barrier detailing for your climate zone. Take the time to coordinate air and/or vapor barrier membrane interfaces with the responsible subcontractor and suppliers. Consider that frame cavity insulation improves overall thermal performance, especially with retrofit panning, but know this must be placed to exterior of the vapor barrier membrane. If wall cavity air is expected to be cold, isolate the window frame inboard of the thermal barrier. Non-permeable air barrier membranes should “tie into” window frame perimeters inboard of the thermal barrier Don’t install windows if air barriers are damaged, torn, discontinuous, or otherwise ineffective. Have the air vapor barrier installer mark the location of studs when critical for window anchorage. Don’t forget that window frames and adjacent wall substrates usually move relative to one another. This must be accommodated in interface detailing. Keep window anchors clear of the membrane system. Ensure that seque
