How does a dry stack stone retaining wall work?
Mass and fit. The mass of the stone holds the weight of the slope behind it if properly fit. Generally speaking, a dry laid stone retaining wall must be 2/3 as thick at the base as it is tall: a 24″ wall should be 16″ thick at the base, a 3′ high wall 2′ thick at the base. Additionally, the stones which make up the wall should be joined such that each vertical joint is overlapped by the stone just above it. Every three to five feet along the face of the wall, stones which might otherwise have their greatest surface stretching along the face (called “stretchers”) should have those greatest surfaces heading back in and through the wall. These are called “headers”, and provide transverse bonding to stabilize the wall. The interior stones off the face of the wall should be well fit. If not and if laid into the wall at obtuse angles, weight on them focuses force rather than absorbing it. There is more to this but let’s stop here.
