Thursday, September 25, 2014

Recommended Reading: Robert's Projects

Robert has a farm in PA and has a load of great posts of farm-scale projects.  If you like the stuff I do but are looking for bigger projects and a wider range of skills, check out Robert's Projects.  Very well considered write ups.

Tuesday, September 2, 2014

Dry Fence Style Retaining Wall

If you wondered why I have been building a stone boat this summer, it was to haul a lot of sand stone and limestone from my little hill-side quarry on the North end of our lot. The purpose for all of this labor was to build a short retaining wall at the site where I will soon be building my combination wood-shed and green-house.

Dry fit stone walls are ancient in origin and require a good eye and patience to construct. To "dry fit" a wall is to use no mortar, but only bits of stone wedged into cracks and crevices to firmly set larger pieces of the wall in place and prevent wobbles. Some particularly skilled practitioners of this art yet today build beautiful full hearths and interior fireplaces from nothing but boulders and river rock.

Stone masons of yesteryear would use a variety of tools to shape stone when it became necessary to cut a stone to fit a need in a wall. Overall, though, tools often being absent, many ancient stone walls that stand today were made with only the materials on hand and a lot of care and patience.

My favorite stone working hammers - the 3 lbs sledge has a home-made honey-suckle handle.

Some of the tools used in antiquity included hammers made from other stones or iron or steel, hand drills which would be hammered or bow-drilled to make holes, and my favorite: splints and wedges. A good splint and wedge set would go along with a hand drill, which would be repeatedly hammered to make a line of holes along the edge you wish to cut. The modern equivalent is an pneumatic impact driven drill. Into these holes, a set of splints would go, then into the middle of each set of splints, a wedge. Tapping the wedges in sequence along the line of holes would steadily increase the pressure and eventually cause the block to fault in a line along the increasing line of stress. Today, we have diamond saw blades and circular saws which can do a much neater job in a fraction of the time. While the cut is nearly glass-smooth, it lacks the charm of the methods of by-gone eras.

I think stacking firewood by the face-cord as a kid conditioned me well in the art of fitting odd sized pieces together to make level layers upon which to stack the wood high and steady. Learning a lesson on what not to do from stacking wood is swift and merciless. A toppling row of logs can inflict pain and bruises as well as frustration. The trick, I have found, is to not only be patient but to consider all of your options. Eventually you get pretty good at visualizing which pieces will fit in the spot you're working and pave the way for a stable structure.  It's also important to not be afraid to undo something that isn't working.  I had three different parts of the wall that were all tight and tamped together, but when walked upon shifted dangerously, so down it came to be built in a more sound fashion.

Starting the wall.

With logs, this quickly becomes routine and simple. I've stacked 2 standard cords of wood in just an hour or two following simple patters of cross bracing for stability and leveling by selecting logs from the pile of like size as I go. With chunks of stone, the game is quite different.

First Section Complete

Naturally, you want a firm foundation. This can be undisturbed soil or compacted gravel. In my case I have a little of both. The gravel pad along which I am building the wall is flush with the earth on the high corner and 16 inches deep on the low side, making two sides sloped enough away from the square and level pad to require reinforcement to prevent erosion and critters or roots from undermining. Upon a level path laid out between stakes in the ground, I start by laying down stones that will create the first level or a monolithic section of the wall. From there, it's very much like assembling a jig-saw puzzle in three dimensions.

Tamping in gravel, using a stick, to fill cracks and stabilize stonework

In my situation, I have a lot of sandstone and lime stone, and a lot of crushed gravel. So I've combined the two in my building process, using the crushed gravel to fill cracks and back fill beneath wobbly stones, and pieces of splintered limestone as shims and wedges to tighten things up. The stability of this method can be attested to by the fact that I can walk on this wall without any wobble beneath my feat. Each stone has been tightly wedged into place and rests firm.

Finished wall with pile of wood waiting for a winter home.  Shed foundation beams pictured at left.

Now that the wall is done, the much harder work of leveling the landscaping beams that will be the foundation of my shed begins. Making one level is not so hard. Interconnecting four in a box with lap joints and leveling and squaring all four will be quite a challenge - especially as each beam requires two people to safely lift off the ground, and I am a one man crew.