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.
The actual cost of an asphalt shingle roof may vary depending on the materials used, your location, the complexity of the installation (i.e. roof slope and home height), and other factors. 1  3-Tab asphalt shingles cost $1.50 to $3.50 per square foot. For an average-sized (1,500 square foot roof), the total cost might be $2,250 to $5,250. Architectural asphalt roof shingles cost, on average, cost around 20 to 40 percent more than 3-Tab shingles, or $2.50 to $5.00 per square foot installed ($3,750 to $7,500). High end architectural shingles, however, could run as much as $6 to $8 per square foot installed ($9,000 to $12,000).