I just heard of the capability to build a fence with untreated lumber and to apply a disodium octaborate tetrahydrate solution after installation.
The alternatives I have been considering are AWPA UC3A pressure treated lumber (PTL) or cedar. My understanding is that both the PTL and the cedar require the application on an initial and periodic (every 3 years) wood preservative (not a stain).
I am looking for the best long-term wood fence solution and prefer to pay higher up-front costs to avoid maintenance and repair in the future.
(The decisions to use wood for the panels and metal for the posts have already been made. The wood panels will be 2 inches above grade and have no ground contact. The wood panels will have a cap on the top so that the grain ends of the boards are not exposed to the weather.)