In order to make your Outdoor gravel patio long lasting , you have to ensure that you have a proper base prepared under the gravel. The quality of the patio does not only depend upon the quality of the gravel but it is also based upon the quality of the base as well. The base is normally made up of bricks on which you have the hardpan. You just need to have a quality gravel that can suit the surroundings of the patios. You need the exact amount of the gravel so that it can cover the whole area. Outdoor gravel patio is normally four inches deep from the bottom of the field that you have prepared.