Day 5 walls

Today was cold and rainy, but despite the weather half of the walls go up. They are built in sections that sit on top of each other with a kind of tongue and groove joint and a rubber seal in between. The walls are filled with blown cellulose insulation which is basically recycled paper treated with a fire retardant coating. The outside is sealed with building wrap which is waterproof and forms part of the vapor barrier that prevents the moisture in warm air from condensing inside the walls. The interior of the walls also has a vapor barrier and a reflective coating to help reflect heat back in to the house. The outside walls have wooden furring strips  to attach the siding. The inside walls have wooden strips to attach the dry wall (plaster board).