the difference between a political and a physical boundary is that a physical map shows geographical features like mountains and rivers while a political map shows boundaries.
Standard Weight. Standard asphalt shingles generally weigh about 190 pounds per 100 square feet, based on information from U.S. Inspect, a property inspection company. The weight of asphalt is especially important if you want to install a new layer of asphalt roofing over an existing layer.A roof measuring 1,600 square feet that has two layers of standard asphalt shingles on it is holding about 6,000 pounds of shingles..S. Inspect indicates that dimensional shingles can be 50 percent heavier than standard asphalt roofing. Therefore, they could weigh about 285 pounds per 100 square feet. Heavier shingles reduce the chance the underlayment will wrinkle, according to the National Roofing Contractors Association.
Material Weight â Pounds per Cubic Yard Asphalt 2,700 lb. Iron (wrought) 13,100 lb. Brush/Branches (loose) 250 lb. Leaves (loose, dry) 150 lb. Brush/Branches (chipped â 3â screen) 600 lb. Leaves (vacuumed, dry) 400 lb. Concrete (gravel or stone mix) 4,050 lb. Leaves (wet or compacted) 550 lb. Concrete (average wet mix) 3,730 lb. Limestone (solid) 4,480 lb. Clay (dry) 2,300 lb. Limestone (crushed) 2,565 lb. Clay (wet) 2,970 lb. Paper (solid - average) 1,565 lb. Crushed Stone 2,700 lb. Plywood Sheets 800 lb.