Accurate cost difference between metal and asphalt roof systems requires examining six distinct expense categories.
Material costs form the foundation. Architectural asphalt shingles run $90-$120 per square (100 square feet) for mid-grade products. Standing seam metal panels cost $250-$400 per square depending on gauge thickness and coating quality. Stone-coated metal falls between at $180-$280 per square.
Labor costs separate dramatically. Asphalt installation takes two to three days for an average 2,000 square foot home, with crews charging $150-$250 per square for labor. Metal roofing requires specialized training in panel forming, seam crimping, and thermal movement accommodation. Labor runs $300-$450 per square and takes four to six days due to precision requirements.
Substrate preparation affects total investment. Metal roofing needs solid decking without deflection, sometimes requiring additional framing reinforcement. Asphalt tolerates minor deck irregularities. Budget $800-$2,500 for structural upgrades if switching from asphalt to metal on an older home.
Underlayment specifications differ. Asphalt needs standard 30-pound felt or synthetic underlayment at $45-$75 per square. Metal requires high-temperature ice and water shield or specialized slip sheets, adding $80-$140 per square to prevent coating damage and allow thermal movement.
Accessory costs multiply with metal. Custom flashings, ridge caps, valleys, and penetration boots must match the metal system. Factory-formed accessories cost three to four times more than asphalt equivalents but provide superior weather sealing.
Disposal fees depend on material weight. Asphalt tearoff generates 400-500 pounds per square, costing $50-$75 per ton for landfill disposal. Metal tearoff weighs less but requires specialized recycling, sometimes offsetting costs through scrap value.