A kneewall space is created when a finished room is built within a sloped roof. Often, these walls are “insulated” using fiberglass batting. Since fiberglass does not stop air flow, the insulation does next to nothing to air seal and insulate----causing rooms sharing walls with kneewalls to be very uncomfortable. Dr. Energy Saver St. Louis air sealed and insulated this Highland, IL homeowner’s knee wall with spray foam insulation. Now, inside air can’t get out of the house through the kneewall spaces and outside air can’t get in. This bedroom is comfortable again!