When paving on grade, new asphalt is placed on finished subgrade or aggregate base material. The new asphalt is laid down using the same process as the overlay below. An asphalt overlay is simply the process of installing a new surface layer of hot mix asphalt directly over existing asphalt on either parking lots or roads. In order to be a candidate for an overlay, a pavement should be relatively sound without large areas of base failure. Prior to resurfacing, pavement repairs and transitions must be made. Cracks should be filled with rubberized crack sealer, and a tack coat applied over the entire surface. A new layer of asphalt is then placed.