The EASE Air Barrier System consists of a sheet of Tyvek sandwiched between two layers of fiberboard on the exterior side of the insulation. This system was used in the entry of the Association provinciale des constructeurs d'habitations du Quebec (APCHQ) for the Advanced House Program. As part of the monitoring program on this house, long-term measurements of pressures, temperatures and relative humidities across the various layers of the wall systems were recorded. Morrison Hershfield was engaged to develop the house's air barrier construction details, analyze the monitoring data and draw conclusions on the performance of the EASE air barrier system.

The monitoring data indicated that the temperature within the insulated cavity always remained above the dewpoint temperature of the air in the cavity. Data extrapolated to estimate temperature at the EASE air barrier itself indicated that there may have been occasions of condensation occurring at this exterior surface in certain weather conditions. Since this did not affect moisture levels further in the cavity, the consultants assumed that this did not create a problem and probably diffused through the vapour-permeable EASE Air Barrier System.

In both monitored wall sections, one with brick cladding and one with stucco cladding, pressure monitoring showed that pressure loads across the air barrier membrane were quite small. The peak pressure recorded across the wall system was in the order of 275 Pa. The majority of the pressure across the wall system as a whole was carried by the exterior cladding materials. Since airtightness testing showed that the wall system was relatively airtight, the consultants concluded that the lack of compartmentalization in the cavity between the cladding and air barrier system limited pressure equalization across the cladding. This sheltered the air barrier membrane from both peak and average pressures.

• air barrier : Tyvek as air barrier
• cladding, siding, veneer : EASE project use brick and stucco cladding
• envelope design : exfiltration air system envelope
• housing project : EASE project
• WRB weather-resistive barrier, house wrap

1. A comparison of airborne ergosterol, glucan and Air-O-Cell data in relation to physical assessments of mold damage and some other parameters
2. An evaluation guide for performance assessment of air barrier
3. Convective processes in loose-fill attic insulation--metering equipment
4. Moldy houses - building science lessons from the Wallaceburg project
5. Rain penetration control - applying current knowledge (rpc-00)
6. Reacting to durability problems with Vancouver buildings
7. Rotting wood framed apartments -- not just a Vancouver problem
8. Stucco-clad wall drying experiment
9. Testing of air barrier construction details
10. The influence of house characteristics in a Canadian community on microbiological contamination  

1. Testing of air barrier construction details