Spray foam acts as an airtight barrier to heat loss and heat gain, particularly in roofs, ceilings, walls and floors. It is mold resistant, dries quickly, and can be easily applied to awkward spaces such as around pipes. When a house uses conventional fiberglass or other air permeable materials, the building will breathe in an uncontrolled manner, relative to wind and changing air pressures. This requires the heating in your house to compensate for cold air from walls and floors that can be mitigated using a comprehensive solution like spray foam.