- Air barrier failure: Can lead to high air leakage, condensation in insulated cavities, comfort issues, high energy use - fix with targeted air sealing.
- Vapour barrier (retarder) failure: Causes diffusion of water vapour and condensation in insulated cavities - fix with interior air sealing and vapour barrier paint.
- Weather barrier failure: Can lead to bulk water intrusion, reduced thermal effectives and structural damage - fix with exterior flashing and caulking
- Thermal barrier failure: Can contribute to frost damage, high energy use, poor comfort - remove damaged insulation, add insulation to empty cavities