A couple of years back I picked up one of those garden benches someone had put out at the curb, with the intention of fixing it up. The wooden slats were rotted and covered in fungus, and the fasteners had all corroded through.
My dad had a friend wanting to get rid of some wood in his garage, so on a trip to Toronto I picked it all up. It included some thick cedar tongue and groove, which Rudi and I cut down into strips to rebuild the seat.
Finally, the fasteners used were all stainless, as opposed to black painted steel, so they won't rust away over the years. I think our project should outlast a store bought bench by about a decade, or more.