These four pictures represent some of the most important points in a dry-laid stone wall construction. (Click each picture to get an enlarged version.)
Compaction and stable ground are critical. The yellow machine in the top left picture is a “compactor” that was first used to compact the sub-base dirt below the gravel, and then finally compact the 12″ of gravel that serves as the “footing” for the wall.
The base course of wall stone and drainage are integral. The bottom course of stone starts at least 6″ below what will be the finished grade of soil. A perforated drain pipe is set behind the wall to gather any water that might collect – it is pitched and connected to the underground seepage pits. Yes, construction technique is very important, but without proper drainage the wall is in jeopardy.
Below left is stone mason Lester Szajna fitting stones as he works his way towards the top course. Most of the stones have to be “tooled” in some way so they fit tightly. This is done with the help of power tools such as cut-off saws, stone chisels & hammers, and hydraulic splitters like the one standing next to Lester. These tools and techniques are what enable well-crafted stone walls to be built efficiently and profitably today.
These are just a few of the important aspects of stonewall construction. In future posts we’ll look at other key wall building factors. Wall design and specific construction details have a lot to do with the situation and site circumstances.
Walls in the landscape are subject to building code review and permit requirements when they meet or exceed certain parameters. Every town’s building codes and ordinances can be different so make sure you investigate before you move ahead. Don’t presume or assume. Nothing is worse than having to rebuild a wall that is non-conforming and/or getting hit with a “stop work order” from the town until the situation is resolved.