In order to insure a continuous air barrier and thermal envelope, the brick exterior is being removed at the Foal House Renovation Project. During demolition, we are discovering layers of durability problems. Promethean Homes (the contractor) discovered Celotex sheathing directly behind the brick layer. The corners of the house were enhanced with plywood to counteract racking. There is no weather resistive barrier (Celotex was impregnated with tar to make it water resisting) and no air barrier.