DIY Home Defenses: Building a Stone Wall Without Mortar
Previously we’ve looked at building earthwork defenses such as spider holes, which were designed to be setup fairly quickly with minimal tools and time spent. Today, we’re going to look at an old technique that was used to build stone walls that have lasted for hundreds of years. Used as fences, boundary markers, and a variety of other structures, these “dry stacked” walls were built without mortar, cement, or any other bonding agent. Instead, these walls are built of shaped field stones and held up with simple friction and the force of gravity. For a prepper looking to construct durable walls that can be easily repaired in an emergency without special materials, these walls are the perfect solution.
The tools and materials needed
Stones should vary in size, but you will need at least a few large, flat stones to build a solid foundation.
Stone. Traditionally, these dry stacked walls were constructed out of the loose stones found lying about the land or that were dug up out of the fields when plowing. Although this technique is still very much applicable today (and might be even more so in a disaster, since property lines and boundaries will be much less limiting when scavenging stones) you could also elect to purchase stone by the ton and keep it in a stockpile for future repair/construction if your area is lacking in stone. You will need stones of all sizes and shapes, including tiny chips that can be used to wedge larger stones and hold them in place. If all you can find are rounded boulderlike rocks, you may need to split some of them to get somewhat flat shapes for certain parts of the construction.
Tools. Although you will not be using mortar or any material to bind the stones together, you will still need a few basic tools in order to shape the stones properly, breaking pieces off or flattening edges to make them fit properly. This list covers the tools you will need:
- 3 or 4lb mason’s hammer. This allows you to break most of the stones you will come across.
- A smaller hammer. This will be used to break small edges off of otherwise good stones.
- A sledgehammer. This will be used to shatter large rocks, in case you need smaller pieces or if a particular rock is simply too large to be used in your wall.
- Tough string and 4 poles about a foot taller than the wall you will be building. These will be put in place to mark the edge of each side of the wall to keep it straight.
- Picks, shovels and other digging tools. These will be used when you are digging a flat spot to build your foundation on.
- A level and tape measure. These will be used for a variety of tasks in order to keep the structural integrity of the wall intact while you are building it.
- Two A-Frames. Although dimensions will be different depending on the height of the wall, a common 4 foot high wall needs an A-Frame that is 3 feet tall, with a 26 inch wide base at the bottom and about 14 inches wide at the top.
- Safety Goggles/glasses. When you split rock sharp shards tend to fly out, so protect your eyes!
Building a solid foundation. The first step in building any stone wall is leveling out a nice dirt foundation that is free of interfering stones, tree roots, or other debris. Using your digging tools, flatten out the area where you wish to build the wall. Although you don’t need to go wild and remove every tiny pebble, any noticeable stones should be removed and used in the wall, while tree roots and the remains of old bushes and other foliage need to be hacked out and removed. If there are trees nearby, know that roots growing into your wall will eventually undermine its integrity unless you place a barrier in their path.
Once the debris is gone, look through your rock pile and separate it out into large, medium, and small sized stones. The largest and flattest should be used to build the foundation, since the wall will narrow as it is built up. Furthermore, larger stones better resist the shifting of the earth and support the weight of the stones above better. If possible, try to ensure that the stones you’re gathering are all roughly the same height when placed on the ground. Also gather a fair amount of the smaller stones, as you’ll be using them as wedges to compensate for the irregular shape of their larger kin.
Once you have your stones separated out setup the poles and string, building two lines on either side of the path where the wall will eventually be. The string should be placed just above the average height of the stones that you will be using for the foundation. It is very important that these strings remain firmly grounded throughout the construction. Every 3 hours you should double check the string to ensure it hasn’t been moved in the process of building the wall, and it should always be checked at the beginning of a workday if the project takes more than one day to complete.
A strong foundation, with a flat base and plenty of large flat stones, will make your wall extremely sturdy.
Now begin laying the foundation stones. You will have two rows of stones to work with, one for each side of the wall. Line them up about 1/16th of an inch from the string but be sure that it doesn’t actually touch it as that could cause the string to bow out and throw off your wall’s measurements. Place them so that the greatest length is facing directly away from the string towards the center of the wall. Once the stones are laid, take small ones and begin wedging them into any place where the bottom of the larger stone doesn’t touch the earth. You want to fill in as much of that empty air beneath the large stones as possible, to create a solid foundation. To test your technique, once you have placed your wedges stand on the large stone. If it wiggles around and moves, you need more wedges. If it is solid and immobile, you are wedging it in properly. Do this for both strings, which will give you two rows of stones with an empty space in the middle.
Fill the empty space between the two rows of foundation stones. Using the small/medium sized flat rocks, fill in the spaces left between the large stones. A good rule of thumb here is to use the largest possible filler stone to occupy an empty space. When you place the stones, shove them up against the larger ones that are already secured and wedged in until the smaller stone can’t move any longer. You want to fit them together almost like puzzle pieces, to the point where they are attached by the friction and weight of each stone on another. Once this task is done, you have finished your foundation.
Now that the foundation is finished, setup the A-Frames at each end and begin raising the wall. The A-Frames need to be set level at each end of the wall, sitting on the foundation stones. Once they are level, use one of the poles or (if you need more stability) a couple pieces of rebar to hold it in place securely. Tie the strings onto the uprights of the frames about 5-6 inches above the foundation stones to show the path for the next level of stone laying. The string should be about 1 inch closer to the center of the wall for each 6 inches of height in the foundation to maintain the proper sloping for the wall, so don’t worry if the string doesn’t match up with the edges of the foundation stones any longer.
Now, taking the largest, flattest stones you have remaining, begin building this layer as you did the previous one. Once the large stones are placed, wedge them in and then fill in the center with stones, interlocking them so that they become one solid layer. If your stones have a slope, make sure that the stones are flipped to position them so that they slope inwards, working with the slope you’re building into the entire wall.
When placing layers, make sure you don’t overlap joints as this creates weak points in the wall.
Raise the strings 5-6 inches, and then continue building additional layers until you have the wall half as tall as you want it to be. For each layer At the beginning and end of the wall, you will need to build wallheads, basically caps for each end of the wall that is better suited to holding without stones pressing in from all sides. These should be made of stones that are slightly larger than the ones used in the layer they are capping, either rounded or flat, and have a regular shape (all rounded, cubed, rectangular etc). These will be laid in a dovetail pattern as you build up your layers, alternating perpendicular placement to give it greater stability.
Once you have built up to half height, place your tie rocks to solidify the wall. Tie rocks are placed perpendicular to the way the wall is facing, so that they will stick out slightly from each side of the wall. They should be flat, and should stick out past the strings by about 2-4 inches for the last layer on both side of the wall. In this case you want just one rock to stick out across the entire wall, rather than having two rocks. Place another tie rock every 3 feet along the wall, securing them with wedges as you go. These are essential for keeping the two rows together and united, so be sure to double check the wedging job you’ve done on these.
Fill in the spaces between the tie rocks as if it were just another layer, and continue adding layers on top of the tie rocks. Continue building the wall until it is up to the proper height, then raise the strings a further 5-6 inches one last time. For the final wallhead, use a large, heavy cube shaped rock to properly anchor each end.
Add the cover stones at the top of the wall. These are flat rocks that are large enough to stick out on both sides of the wall, just like the tie rocks did below them. Unlike the tie rocks, these are placed right next to each other along the entire wall before they are wedged in.
The vertical pieces are the coping of the wall, and act as a final layer, increasing height and improving the wall’s durability.
Finally, add the coping to finish the wall completely. The coping is made up of smaller rocks positioned vertically and angled slightly to cover the entire top of the wall except for the wallhead caps. They should be of uniform height, just below the strings. You should setup all of the rocks before putting a wedge between each of them. After tapping in the wedges you will need to go back through and tap them in again, since the entire unit will tend to loosen somewhat as the wedges are first put in.
And with that, your wall will be done. It can be used to create cover and concealment, as a way to shield a cache or other vital supplies from looters, or to contain livestock. Although a stone wall takes longer to build than a simple earthwork it is much more durable in the long run, making it an excellent preparation for before a survival situation kicks in.