Mallard Systems will provide at no additional charge the service necessary to maintain a spot-free absence of mold, mildew, and algae from your roof for one year from the first cleaning and sanitizing date. This warranty covers shingle, concrete tile, clay tiles, slate, and any composite roofs that have no water pooling. This spot-free warranty is transferable to the new owner of the property. Extended warranty periods may be offered at the discretion of Mallard Systems.