So as I finished digging the hill back to the necessary perimeter for the barn, I also continued trying to find an alternate kind of retaining wall a bit less heavy than seventeen tons of stone. My trusty Home Depot Outdoor book included the suggestion of a post-and-board wall. Since I happened to have a fair amount of treated 2×6 boards from my friend’s demolished deck, I decided to sink my upper four posts into the ground (rather than sitting on padstones), cement them in place, and plank up the wall on their uphill side.
After looking at my poles again, I found I had four long enough to sink three feet into the ground and still give me enough height to make the 7’6” beam height. So I set about with a auger-style post hole digger driven by 1/16 horsepower, as Shannon Rogers likes to say. HOwever, I got no more than 18 or so inches down when I hit ROCK. And I don’t mean A rock, I mean either bedrock or a boulder half the size of the barn site! I tried shifting the hole to one side slightly. Rock. Then the other. Rock. And what I was hitting was a flat shelf without even an edge, even after I widened the hole to about three feet in diameter… Frustrated, I gave up that post hole and moved to the other post on that wall, about 8 feet away. Guess what? The same kind of rock at the same depth.
I have absolutely no tools that would allow me to tunnel through rock like that, and if it was a huge boulder of that size I would have no way of digging it out even if I could dig around it (and its removal might destabilize the hillside!). A new plan had to be made.
As a test, I moved down the hillside (into the barn area) about three feet and tried another hole. This time I got down 24 inches before hitting rock. That gave me a plan. Instead of a single retaining wall, I would stair-step two of them. The first wall would actually be about three feet inside the barn’s uphill wall and be about 17 inches high (three 2×6s). This would create a raising sleeping platform for the goats, and also at one end create a ready-made milking platform if I included a stanchion at that point in the dividing wall. The second wall would start where the first stopped, and continue to rise three or four planks higher until it achieved the full height I needed. The height of the lower area would also add to the depth my posts could be sunk into the earth, and I could achieve a three-foot depth successfully.
The lower area would be 18” high by 3’ deep by 18’ wide…and yes, it meant I would have to shovel all the earth BACK that I just dug out, as well as adding a buffer of about 1 foot of gravel between the earth and the wall to preserve the wood by keeping water away (a similar gravel buffer would need to be placed abouve the upper wall, and since that wall would outwside the wall perimeter, it would also need a drainage pipe at the bootm and landscape fabric to keep soil and plants from inflitrating the gravel.
Reshoveling the dirt was a daunting prospect, but as my friend Alicia says: “Ain’t nothing to it but to do it.”