An Exploration of Wall Retrofit Best Practices

Abstract

A series of experiments were performed to examine wall retrofit options including replacing the cladding, adding insulation under the cladding, and multiple sealing methods that can be used when installing replacement windows in well-built or loosely-built rough openings. These experiments included thermal measurements in a hot box and air-leakage measurements. The retrofit claddings considered included wood-lap siding, vinyl siding, and vinyl siding with an integrated and formed foam insulation. Retrofit insulations included expanded and extruded polystyrene and foil-faced polyisocyanurate in various thicknesses. Air sealing methods for replacement windows included traditional caulking, exterior trim variations, loose-fill fiberglass, low-expansion foam, self-expanding foam inserts, and specialty tape. Results were applied to a model to estimate whole-house energy impacts for multiple climates.