Skin patches are thin layers of asphalt placed over an existing surface, usually to resolve water flow issues or improve the appearance of rough pavement. It is often recommended before an overlay or seal coat.
This treatment does not address structural or base course problems, and may therefore only be a temporary fix, especially if used to fill in areas that have gradually sunk over time. If this is the case, asphalt reconstruction is more appropriate.
Skin patches are generally 1-2", but can be up to 3-4" thick.