THIS CHAPTER HAS BEEN EXPANDED BY ITS FIRST-edition author to include additional information on: • Building codes • Climate zones • Metal roofing • Steep roofing • Structural insulated panels • Freeze-thaw damage to insulations • Ventilation of attics and cathedral ceilings • Ice dam protection underlayments • Vapor retarders for compact roofs • Self-drying roofs and downward drying of wet roofs • Sliding snow hazards and solutions • Finding leaks and wet insulation • Air barriers and the necessity of controlling air leakage