Existing home attic spaces present the best place to begin looking for energy efficiency improvements. They are typically readily accessible, represent a large part of the total surface area of the envelope and provide an opportunity to greatly increase the efficiency and comfort of the home. Sealing these spaces will help maintain the thermal energy in the home by cutting off a key contributor to heat loss through convective loops. In addition, with most Southern New England homes built prior to 1980, the quantity and type of insulation materials found is sub-standard. An R-19 fiberglass batt installed in your attic floor back in 1978 can perform to half of its stated R-value due to the effects of gravity, moisture and maintenance interference over time. It is also important to note that any insulation products found in homes prior to the 1960's can be hazardous to indoor air quality. Products such as asbestos or vermiculite are still found in many homes around the North East.
When choosing spray applied foam insulation for the attic there are two application approaches that can be explored:
Unvented Attic Assembly: Where foam insulation is installed against the roof sheathing sealing up soffits, ridges and gable ends. This method places the attic space within the thermal envelope along with any HVAC equipment that may be installed in the attic space. This is an excellent approach to addressing ice damning issues and increasing the effectiveness of existing HVAC systems.
Vented Attic Assembly: Where insulation is installed to the attic floor. In this method, conventional venting is exercised through the use of soffit baffles, soffit vents and ridge vents or gable end venting.
