The SPF roofing process is begun by cleaning the entire roof area, ensuring a tight bond. Then a closed cell, three-pound polyurethane foam at a minimum 1½” thickness is applied to the entire roof area. This liquid will provide an energy-efficient roof as it expands into a solid foam. Then a base coat is applied at approximately two gallons per square foot on the complete roof area. This sustainable roof is completed by applying a white reflective top coat at approximately two gallons per square foot. This retrofit roof can withstand up to 50 years of use. For many scenarios, this system is a solid win.