Client wants me to pull out his rotten RR ties and replace them. I have never worked with lumber in the landscape, and wanted to ask you guys if I can just do a cut-and-paste.. pull out old ties and rebar, put in new ties and new rebar. Or do I need to go below grade and build a base so they stay level? I was going to use fabric on the 2nd tier, where there are 2 ties stacked, but didn't think fabric would have any purpose where there was just 1 tie. All input is appreciated!