Walk any East Tennessee neighbourhood built on a slope and you will find a retaining wall with a belly in it — a bow, a lean, a course of block sliding off line. It is tempting to read that as cheap material. It almost never is. What moves a wall is water.
Soil holds water, and wet soil is enormously heavier than dry soil. After a week of the long soaking rains this region gets in winter and spring, the ground behind an unwarranted wall is not soil any more so much as a pressurised mass leaning on every square foot of the structure. The wall was built to hold back a hillside; nobody told it about the reservoir.
This is why the part of a retaining wall that matters most is the part nobody sees: the drainage behind it. Clean crushed stone against the back face, a perforated drain pipe at the footing with somewhere real to discharge, and weep paths through the wall give that water a way out. Relieved of the pressure, the wall only has to do the job it was designed for.
The base matters the same way. A wall stacked on topsoil settles unevenly and opens its joints; a wall on a compacted, levelled base of the right depth moves as one object through freeze and thaw. None of this shows in week one — a wall built without it and a wall built with it look identical on the day the crew leaves. They stop looking identical a few winters later.
Retaining walls — block or natural stone, with the drainage treated as part of the build — are the lead service at Garcia's Hardscape. To talk about a slope, call (865) 314-3287. Hours are Monday–Saturday, 8:00 AM – 7:00 PM, and estimates are free.