Experience unrivaled Commercial and Industrial roofing solutions with A-1 Seamless Roofing! Leveraging a strong track record of maintaining, repairing and replacing roofs in Iowa and southern Minnesota for years, David Borntreger and his team have built a strong reputation as roof-waterproofing experts. Offering several options in order to help all building owner find a waterproofing solution that meets a specific budget and set of goals, A-1 Seamless Roofing has the experience needed to handle every roof type.