The existing asphalt was in perfect condition, so naturally the homeowner didn't want to pay for a redundant tear out and replacement process. Comfort Radiant suggested a retro-fit installation. We saw cut slots in to the surface 1" deep x 1/4" wide and lay the Tuff Cable element into the slot and sealed over the top to a flush finish. The lines are visible but, as with all asphalt driveways, when it was seal coated, they blended nicely. The picture clearly shows no ice or snow where the system is installed.