PDD Exam 1 Sec 1 Questions & Answers 2024/2025

PDD Exam 1 Sec 1 Questions & Answers 2024/2025 Flat Roof Slope - ANSWERSLess than 1/4" per ft < 0.25 : 12 e.g. Blue roofs: intentionally pond the water or keep the water in containers inside the building e.g. used for high rises in NYC Low Slope Roof - ANSWERSLess than 2" per ft < 2 : 12 - Relatively slow drainage, small errors result in ponding - Membranes must be flawlessly watertight - Water vapor from the building inside or wind from outside can cause blistering, flapping, displaced or cracked members - But can cover buildings of any horizontal scale, simpler geometry, and can be planted, occupied - Locate drains in mid-span between structural support - Min 2% slope Steep Roof Slope - ANSWERSMore than 2" per ft > 2 : 12 - Gravity sheds water quickly, so we overlap small units (shakes, shingles, thatching, clay or concrete tiles) - Smaller units can be easily repaired or replaced, and can bend and flex with the roof's expansion and contraction. Visible Green Roof - ANSWERS- Min Pitch 10-20%