The Details You Need to Know
Roofing is usually quoted by the square — that is, one hundred square feet of surface. Because the slope of your roof means the actual size on the ground is smaller than the size on the roof itself, a house that is forty feet by fifty feet does not have a twenty-hundred-square-foot roof. A shallow pitch makes the difference smaller, a steep pitch makes it larger. Any reputable contractor will calculate this for you and show you the math.
The material quality splits into three tiers: budget three-tab shingles (about ninety to one hundred ten dollars per square), architectural shingles (roughly one hundred to one hundred fifty dollars per square), and premium or designer shingles (often two hundred dollars or more per square). Those numbers add up: a two-thousand-square-foot roof is twenty squares, so architectural shingles at one hundred fifty dollars a square come to about three thousand dollars in shingles alone, before underlayment, flashing, fasteners and labor.
The single biggest variable is whether this is a repair or a replacement. A repair that patches a section of flashing costs between three hundred and eight hundred dollars and takes a day. A full replacement that strips everything down to the decking and starts over costs six to fifteen thousand dollars depending on roof size, pitch, and material choice. Some contractors offer partial replacements when only one side of the roof is damaged — ask about this option if you are trying to spread the cost across more than one year.