There is a variety of different things you can do to maintain the life of your split rail fence. Once you install your fence if you stain it or oil it regularly this will act as a protective layer for the surface. Conducting regular inspections of your fence to make sure there are no defects is a great thing to prolong the life of your split rail. Of course, if you ever notice any repairs that need to be done make sure to replace or repair anything in a timely manner.