This is the most common form of attic ventilation – the attic floor is insulated so the attic stays cold (avoiding issues such as ice damming) while the rest of the house stays warm in the winter.
- Stack effect occurs when heated air escapes through the ceiling into the attic from upper levels of the home and is replaced in lower levels of the home by drawn-in, outdoor air. This occurs with conventional insulation types, such as rockwool, because they don’t meet air barrier standards (based on air permeability testing, ASTM E 283). Therefore they don’t sufficiently stop air flow/leaks like Icynene® spray foam insulation does, and they can sag or settle over time.
- In heavy snowfall areas, ice damming is a common problem due to warm, moist interior air coming into contact with the cold roof surface, where the moisture then condenses and freezes.
Results of Insulating Attic Floor with Icynene Spray Foam Insulation
- Improves in energy performance for savings
- Minimizes potential for water/moisture damage and associated health concerns (mould) that can result from ice dams