I've been working in a condo community for the past month replacing old railroad tie walkways and replacing them with 6x6pt. So far all the walkways have been flat, but the next one will be a challenge. It changes in elevation about 6' from one end to the other. Originally the left side of this walkway was a retainer for the walk 3' to possibly 10' high. Recently they have had another company replacing tie retainers with rock, and when this area was done they simply stacked their rock within a foot or so of the tie wall and backfilled. The same rock guys are now putting another retainer on the right side (uphill) and the POA wants us to replace this walkway, but I'm not sure the best way to do this. If we build off the existing ties it won't match up properly b/c of difference in lumber thickness (which isn't much but after a couple steps it gets huge). I don't wanna remove all the old ties because they could be at least 5 or 6 ties deep and it connects with another retainer that is probably 10'+ and hidden behind rock. Plus if we start pulling these out there are safety concerns with the rock wall. My biggest concern is settling b/c the actual walking surface is pavers, not so much the pavers settling but the timber. They have talked about reworking the walk b/c it has a couple 30 degree bends but then I'll definitely be working on fill with ties in spots and I think this would cause more uneven settling. I think my only option is to take out the first two or three layers of ties and then use sand to build up on top of what's left in order to work out my height difference and still have stable ground to work on. I know from the other walkways too that ties buried in the ground are in great condition compared to those which are partially above ground, but since the left side used to be visible it could be rotten I'll never know unless I pull them all out. I really like to do things the right way the first time and getting paid by the hour so I don't wanna take shortcuts.