Sunday, December 30, 2012

How I'm Building a Stone Wall

In the previous post, click here, I talked about the stone wall I’ve been working on. In this post I’ll try to explain my process. It took some time to figure out how to get things to work. The challenge of dry stacking a stone wall is that, essentially, it’s gravity that holds it all together. There’s no mortar or concrete. Here’s some of what I figured out.

First, there are a few precautions regarding safety if you are considering building a stone wall. Do all lifting with bent knees, and don’t pick up rocks that you cannot safely maneuver. Learn to gauge your strength, and only do what you feel physically capable of.  

Wear gloves that protect your hands. On days that stones that are wet or damp I wear rubber-coated ones. Leather works well for dry stones. Fleece-lined leather ones are needed for working in chilly weather. Gloves are to protect your hands from rough surfaces, not from falling stones.

Never set a rock or stone in place. Instead, drop them in place. As the rock is falling downward, as a precaution your hands should be moving upward. Dropping a stone often creates a loud and sharp sound, so wear ear protection.

Avoid any temptation to influence the rock's landing. After it lands, and only then, feel free to grab onto it and twist, turn, or even roll it until it settles in. If a stone or rock misses the wall, jump backward quickly. Did I say 'wear work boots?' They are a good idea and steel toes may be helpful, but it's still a good practice to never let a stone or rock land anywhere on you.

Now that you’ve got all the warning stuff, here’s my take on the actual building of a stone wall.
The largest rocks form the bottom of the wall.

The biggest rocks go on the bottom. These are rocks that are too big to be picked up, but can be rolled. I transported some of these by rolling them across the field. Others were brought in the tractor bucket, by far the easiest way to do it.

The biggest ones are set along the property line. I line them up along the string I ran earlier to get the wall exactly straight. Running a string is really the only way to make a perfectly aligned wall. I simply tied a string onto one property marker, ran it to the next one, pulled the string tight and tied a knot. These stones should be set, if at all possible, so they end up with a flat top. It’s easier to build upward if the surface is somewhat level. 
The string used to line up the rocks is at the top of the photo, and there is a row of rocks for the back, and one for the front of the wall. 

A second row of rocks is then lined up along the front of the wall. I don't use a string to mark the front. This is eyeballed and based on experience.  I've learned that a certain width is too narrow to withstand the layers of stones that I want to add later. This is one reason I've pulled apart sections of wall to restack them as mentioned in the earlier post. The base of the wall must be of a width that will accommodate the layers of stones that will make up the height. The wall naturally tapers inward as layers are added.

After lining up the front stones I then fill in between them with small stones. These are called rubble. Rubble consists of all of those smaller stones that are too small to use for stacking.

After the center is filled in, the wall is ready for stacking. Everything from here on up will rely on your stacking abilities. Here are some things I've learned about this.

Each rock stacked onto the wall should be stable as it is set, or it should lean slightly inward toward the center of the wall. Rocks shaped long and narrow help to stabilize the wall if they are set to run toward the center rather than lengthwise. Sections can be done by fitting smaller stones together and then capping them with a large flat one.

I often scrounge for pebbles and small stones to fill cracks and gaps on the top of the wall. I rarely chink stones into the sides of a wall- they tend to fall out and are not needed for the structure of it.
Looking downward: stones are fitted together to create a layer. Note the narrow stones that are set to run toward the center. 

The very top of the wall is best finished with large, flat stones covering as many openings as possible. Squirrels will shuck pine cones on your wall, and leaves will fall on it, and this stuff turns into woodland compost and eventually trees will begin to grow out of the top of your wall. Because of this I try to seal it as well as possible.

An important thing to forget about when building a rock wall is time. Never mind the amount of time it takes and just get out there and move rocks when the weather and bugs allow. It’s finished when it is. -jmm

Monday, December 3, 2012

I'm Working on my Stone Wall

I've always admired stone walls. They configure the countryside around here, outlining fields and roads and often determining property lines. They are especially nice in those farmyards where someone took pains to neatly stack stones into picturesque walls. Others are more rustic looking, having served the purpose of getting a field cleared of rocks.

Our fieldstones are many different shapes. There are rounded ones, broken ones that might have a flat side, triangular or wedge-like ones, and all too few slab-like ones. Some of my favorites are rare to find; thin, wide saucerlike pieces that got broken off of ledge. Occasionally you find one that is shaped like a shallow bowl and could be used to make a birdbath. Fieldstone sizes vary from pebbles to stones, and to rocks that are too big to move. None of these are shapes that easily fit together.

When this piece of land came along, a stone wall was the only thing lacking. Over the years I’ve started garden beds and various landscaping projects. Piles of stones and rocks accumulated, so eventually I got the idea to try building a stone wall. I hadn’t a clue about building with rocks. I lined them up, and then proceeded to stack them. Most of this early work has since been taken apart and done over. You learn by doing.

The wall I’m working on is 237 feet long, and most of it has been rebuilt at least once. This fall I’ve been rebuilding sections of it for a second or third time, and hopefully for the last time. I’m determined to get it right. After starting this wall I have begun work on several more stone walls, just as lengthy. It will be a few years, but I’m determined to have stone walls.

Somewhere along the way I did some research. I found that one should begin with a trench and fill it with rubble or pour in concrete. I do not find that practical nor apparently did New England farmers who stacked their walls on the surface of the ground alongside their fields. The filled trench is to prevent frost heaves, but if any frost heave happens to topple a section of wall, I’ll simply rebuild it. Not a biggie. I know how.

In my research a question emerged asking why some walls are low, and whether they could have sunk. So I wondered whether my walls will sink into the soil. This land is not tilled soil, but is the same forest ground that has been here since the last glacier, so I figure probably not. Yes, rocks would sink into tilled soil. It’s full of air spaces. I wonder, instead, if many years of leaves being caught beside the walls caused trees to root into the leaf mulch and thereby the ground level rose. This is what happens if you try to make compost in the forest. It becomes fodder for roots.

In our recent 4.0 earthquake, I went out the next day to find that not a stone had dislodged from my stone wall in all of that shaking. Maybe it helped some of the stones to settle in better. Or maybe it’s a testament to my stacking abilities. Not at all sure, but it made my day to find the stones intact.

In a next post I’ll reveal a few things I’ve learned about dry stacking a stone wall. -jmm