This information has been devised by members of the Stone Trust and separates the build process into its component parts.
Foundation: This is what the wall is built on. For field walls it is often the native soil with the turf removed. Landscape and garden walls may be built with a bed of crushed stone or gravel.
Footings (commonly called Foundation Stones): The footings are the stones that make up the bottom layer, or course, of stone upon which the rest of the wall sits. The Foundation Stones are usually the largest stones in the wall, and may be partly or entirely below ground depending on the conditions in which the wall is being built.
First Lift: This refers to the lower portion of the wall, from the foundation to the level of the through stones. This includes the face stones, hearting and pinning. The first lift is made of larger stones than the second lift.
Through stones: These are stones that extend through the wall, connecting the two sides. They are typically set roughly every meter along the wall and are halfway up the height of wall. The purpose is to prevent the sides from separating and are absolutely crucial to building a sound wall structure.
Second Lift: This is the top half of the wall, between the through stones and the cope. Like the first lift the term is inclusive of the face stones, hearting, and pinning. The stones are typically smaller than those in the first lift.
Cope: These are the top stones on the wall. There are numerous styles used for copes, but they all basically serve the purpose of adding additional height and capping of the wall in a structurally sound manner.
Hearting: This is the small stones used to fill in the gaps between the face stones in the wall. Hearting is scaled, like the face stone. Larger hearting is used near the bottom of the wall and smaller pieces near the top.
Pinning: Pinning stones are used to hold the face stones in place. They are very similar to hearting and could be considered a part of the hearting. But pinning stones are specifically chosen and placed to wedge the face stones in place, where hearting stones are only roughly placed to fill in gaps.
Batter: Batter is the term used to describe the angle of the face of the wall. In other words the wall is narrower at the top than the bottom so the sides are angled inward. This angle is the batter.
Course: A course is the term used to describe a layer of face stones in the wall. Some walls are built without courses, which are referred to as random walls. In many walls however the stone is arranged into courses. The courses may be more or less rigid depending on the stone, walling style and the waller.
Face stones: Face stones are the stones that can be seen in the side of the wall. The face stone make up the majority of the volume and structure of the wall. They are sometimes referred to as ‘wallstones’.
Face: The term face can refer to the wall collectively or to individual stones. In both cases it means the side(s) that can be seen. In other words the side of the wall is called the wall face. But, the side of a stone that is visible in the finished wall is called the face of the stone.
Is a DIY dry stone wall possible?
While it takes a great deal of skill to build a near perfect wall, building a good strong wall is within the reach of most people who like do-it-your-self projects. The 5 rules below are applicable in nearly all dry stone projects. Always remember your aim as the waller is to maximize friction between stones.
1. Set the length of the stone into the wall:
This means that the end of each stone is the part visible in the final wall. In other words the length of each stone is perpendicular to the direction of the wall. Think of how firewood is stacked, with each piece perpendicular to the overall direction of the stack, so all you see are the ends of the pieces. A stone wall should be built the same way.
When stones are placed with the wall so that the sides are visible, it creates a much weaker wall and is called tracing. Tracing is one of the most common errors made, and is one of primary reasons walls fall down.
2. Heart the Wall Tightly:
Gaps in the interior of the wall, between the face stones, should be tightly filled with small stones. The tighter the hearting, the stronger the wall. However fewer larger hearting stones are much stronger than many small little bits. Anything that can be easily shoveled is too small to use for hearting (and absolutely no concrete gravel or soil!). Hearting stones are much better if they are flat or angular. Rounded stones can act like ball bearings. Hearting stones should be placed individually, not randomly thrown in. Hearting takes place as the wall is being built, make sure each course is completely hearted before beginning the next course. Not properly hearting a wall allows stones to move independently of one another, resulting in a structurally weak wall that will not last.
3. Cross the Joints:
This means that each stone should be crossing a joint below so that it is setting on two stones below it. What should not be done is to stack stones so that there are vertical joints running from one course to the next. Such joints are called Running Joints or Stack Bonds. Walls with running joints are very weak and look poor. The image to the left is looking at the face of a wall.
4. Keep Stones Level:
Walls should be built so that the stones and courses are level. This is more apparent when using flat stones but applies to nearly all walls. Stones should be level both into the core of the wall and along the face. Stones that are not level will tend to slide causing internal stress in the wall and will eventually cause failure as the wall shifts over time. Many walls are built with quite irregular shaped stone, when this is the case focus on keeping the top of the stones level. That makes it easier to build on top of. When this is not possible to have a level top, slope it top toward a neighboring stone to the right or left. Not into the core of the wall or pitched out.
While there are a few local styles and techniques that don’t follow this rule (ex: herringbone wall), it should be followed when building typical walls, and especially when you are learning to build. This rule is especially important when building on sloping ground.
5. Build With the Plane of the Wall:
This means to align the stones so that there is an even plane to the faces of the wall. String lines are especially useful to keeping an even plane to the wall. The outer most ‘bump’ of each stone is what should be in-line. By doing this the wall will look smooth and even. This applies both in cross section and in each course as the images below show. It is easy to get out of plane by building with the face of the stones below rather than following guide strings and always lining up the outer bumps of each stone.
These are the basic rules of walling. If these rules are followed your walls should be strong and beautiful. There are also many more techniques that will make your wall even stronger, and features that can be incorporated for different purposes and situations. Come to one of our many workshops to learn how to build a stone wall for yourself!
Dry stone walling does include some elements of risk. By using safety gear, proper techniques, and being safety conscious, you can dramatically reduce the chance of injury.
Wearing the appropriate clothing and safety gear is important when walling. Steel-toed boots are very important. It does not take a very large rock to seriously crush a toe.
While some professional wallers prefer to work with bare hands, most people prefer to wear gloves. I find that the cloth covered gloves with the palm and fingers coated in rubber provide the best combination of protection and dexterity. Different weights are available for different temperatures. Leather gloves provide more protection, but limit dexterity. I do use insulated leather gloves in the winter to keep my hands warm. However, even the toughest leather gloves only last about for 50 hours when working with stone. Don’t be tempted to use expensive builders’ gloves (Iron Clad, etc.) as they only last about 1 day before wearing out. One of the best sources for gloves and other safety gear is Galeton.
I always recommend wearing long pants and sleeves when working with stone. It saves me from numerous minor scrapes and abrasions. If you choose to wear shorts expect to get scraped up a bit. In hot temperatures I use clothing made from lightweight light-colored fabrics. I find that I stay surprisingly cool because my skin is shaded from the sun.
Eye protection is very important if you are doing any reshaping or cutting, and really should be worn continuously. Invest in a comfortable pair of safety glasses so you’re not tempted to take them off. You only have two eyes, and you want to keep it that way. If you are using any power tools (drills, saws, etc.) be sure to where ear and eye protection along with anything else instructed by the manufacturer.
Breathing stone dust, particularly the fine dust from running dry power saws should be avoided. While limestone based dust is not directly harmful, silica dust is. Granite, and related stones, along with Portland cement is very high in silica so it is important to avoid exposure. If you have to dry-cut stone wear a respirator.
Safe Building Techniques
- Keep a work space clear of loose stones right along the base of the wall you are building. Typically 18-24 inches wide is sufficient. Walking on loose stones all day is both dangerous and tiring.
- Don’t try to lift stones that are too heavy for you. Primarily lift with your legs, not your back. If you are working with stones too big to lift, pry-bars and blocks of wood can often be used to great effect. If you take your time, you can safely move very heavy stones using levers. Planks can also be used as ramps to roll or slide stones up onto the wall.
- Make sure any stone you are putting your hand under is very secure. A light stone falling just a few inches can seriously crush fingers.
- Try to avoid holding a stone with one hand while pounding on it with a hammer. The vibrations going up your wrist often eventually cause problems. Instead prop the stone under your boot, or in such a way that you don’t have to hold it at all.
- If you are working with others make sure you have clear vocal signals and a specific plan before you lift a stone together. Miscommunication is one of the most dangerous aspects of moving stones by more than one person.
- If equipment (tractor, excavator, etc.) is being used, work out a detailed set of hand signals with the operator before you start. If you are yelling over the equipment noise you are risking miscommunication. When working around equipment, make sure the operator completely removes his or her hands from the controls before you approach the bucket. An accidental movement by the operator can be very dangerous.
- Watch your hands. When you are stripping out or loading stones, keep your eyes on your hands, not on the next stone you’re going to move. Some of the worst finger pinches I have seen were because the waller took his eyes off his hands in an effort to work faster.
- If you are using rebar for stakes to hold string lines, buy the plastic safety caps that keep people from being impailed if they fall on the end.
- Avoid breathing stone dust, particularly when using power tools to shape the stone. Breathing stone dust eventually will lead to silicosis, which cannot be healed.
- Be Safety Conscious.
If you start to think that what you are doing is not that safe, it probably is not. Stop and think of a different way to do it. Try to plan ahead, if you are moving a heavy stone; clear a path before you pick it up. Nearly all injuries related to walling are due to rushing. You want to work efficiently, so think ahead and communicate clearly. Don’t rush or try to “get away with it this time.” That is when people get hurt.
Setting up is one of the most important parts to building a wall efficiently. Setting up for rebuilding an old wall involves stripping out the existing wall, and preparing the foundation. Setting up for a new wall includes preparing a foundation, having stone brought to the site, and organizing the work site.
Rebuilding an old wall
If you are rebuilding an old wall, rebuilding typically happens in sections 10 to 25 feet long. Each section should be completely rebuilt before moving on to the next section. Starting on the first section, setting up begins by clearing any brush or debris from both sides of the wall. Ideally you want reasonably clear ground for about 10-15 feet on both sides of the wall.
Once you have clear space, begin disassembling the wall, this is called stripping out. Take the time to sort the stones as you strip out. This will speed up the rebuilding. Stones should primarily be sorted by thickness, with thicker stones near the wall, and thinner stones farther away. Through stones should be set aside, and cope stones should be set farthest from the wall. Small stones to be used for hearting should be placed in piles near the wall every 6 feet along the wall.
On a freestanding wall, stones should be equally distributed on both sides of the wall, don’t put thick stones to one side and thin stones to the other. Remember to leave a path clear of stones about 18 inches wide right along both sides of the wall. This gives you a place to stand. On retaining walls, typically all the stones should be stripped out to the downhill side. Excavated soil, and sometimes cope stones or hearting, can be placed on the uphill side. The Stone Trust has written detailed engineering specifications for dry stone retaining walls for use by contractors and designers, click here to access these design specs.
Generally speaking all the stones should be removed, right down to bare dirt, when stripping out. Any roots or organic debris in foundation should be removed and dirt should be flattened and firmly compacted. Stomping back and forth several times with your boots is typically sufficient. If the wall is going up a slope, step the foundation so you have level shelves. The foundation should typically be 4-6 inches below ground level on the lower side. Going deeper serves little purpose and uses up more stones. If the footing stones are excessively large, they can be re-positioned one at a time without fully removing them from the wall foundation. Once the stone is sorted and the foundation is prepared, you are ready to set up string lines and begin building.
Building a new wall
Building a new wall begins by preparing a foundation. When building a field wall, remove any topsoil, roots and organic matter from the where the wall will be built, and firmly compact the subsoil. Typically 4-6 inches below ground level is sufficient. Just like for rebuilding, clear space is needed along the wall. There should be sufficient access to have the stone delivered right next to where the wall will be built. If not, you will need to figure out a way to get it there. When stone is delivered in a dump truck it leaves a big pile, sizes are all mixed up, and hearting, if there is any, is at the bottom. It is worth every bit of your time to sort through the pile before you begin building. I find the most efficient method is start on one side of the pile and sort it into rows according to thickness, not overall size. As the pile gets sorted the rows get longer. I set this up so that the rows are parallel to the wall, with the thickest stones closest to the wall.
If you are working from palletized stone, it is still often worth opening all the pallets and sorting through the stone before beginning to build. Some palletized stone is already graded by size in which case further sorting is not needed. However, these pallets are often intended for veneer, and lack the large stones you need for though stones and features. I try to avoid palletized stone whenever possible. It is more expensive, tends to have inadequate size variation, and dealing with the pallets and wire cages takes time. You also need a big piece of equipment to move pallets of stone, which often weigh over 4000 lbs.
Determining how much stone you need for a new wall is always a challenge. When buying stone by the ton, I find I get about 10 cubic feet of wall per ton of stone delivered. Note that is cubic feet, not square foot of wall face, so if your wall is an average of 2 feet thick and 45 inches high, 1 ton of stone will give you 2 feet of length. This translates into about 1.8 tons per cubic yard of wall built. Of course, there is considerable variation due to the density of the stone, and how tightly the stone is stacked in the wall, so this is just a place to start.
A basic understanding of stone is important to be able to wall efficiently. Some stone is easy to work with, and other stone can be very challenging.
Wall stone can be divided into two basic categories: level bedded and irregular. Level bedded stones have parallel top and bottom surfaces, and will often split into thinner stones. Slate and shale and sandstone are typically level bedded stones. Some limestone and schist are also level bedded. Some wallers will also refer to level bedded stone as regular stone.
Irregular stone accounts for all stone that is not level bedded. It can be angular or rounded. Irregular stone does not have flat parallel surfaces, and will not usually split so that it does. Granite and marble both break into irregular shapes. There is a continuous range from stone that is clearly level bedded, to stone that is clearly irregular. Most stone is somewhere in between. Irregular stone can also be cut, or split using feathers and wedges, to form regular shapes that it would not form naturally.
Walls built with level bedded stone often look neater. Irregular stone tends to look more rustic. However the skill of the waller and style being built affect this as much as the stone. Walls built with larger stone also tend to look more rustic. Smaller stones tend give a more tidy look. While you want to build the best wall possible, don’t try to force the stones into a character they are not.
Stones come in all different shapes. The images below show some common shapes divided by how easy or difficult they are to build with. Some stones with difficult shapes can be trimmed (edges or points broken off) to improve there usability. Other difficult stones can be sporadically used throughout the wall, with better stones in between, without adversely affecting the look or structure of the wall. The very worst shaped stones often get smashed up into hearting. It is important to use all the stone in a consistent manner. There is a tendency to use all the nice flat stones right away, and then have a bunch of awkward shapes at the top of the wall. This looks poor and often weakens the wall.
Breaking stones is a skill in itself. Each type of stone works differently, some break easily and some don’t. Generally, breaking or shaping stones should be kept to a minimum, your objective is to build a wall and not to carve stones. It is always easier to break off the corners of a square stone than to make flat sides on a round stone.
How a stone is supported often effects how it breaks, as does the direction it in which it was struck. I often find the speed with which the hammer strikes the stone is much more important than the apparent force or pressure exerted on the hammer when it strikes the stone.
The best way to learn how to break a stone in the way you want is to practice. Pay attention to how each stone breaks when you hit it. If it does what you want, then remember what you did. If not, adjust your technique for next time and try again.
Chisels are great for splitting stones along their natural bedding (with the grain), and can be used for trimming and other breaking. While they give you more control, they take more time to use, so most skilled wallers only use them when precise control is needed. Points are like chisels that taper in from all sides to leave a point that can be used for removing high spots.
Some hammers and chisels are available with carbide edges. This is very useful when working with hard stones like granite, which will quickly round over other hammers. However, these tools are quite expensive and require special grinding wheels to properly sharpen them, so they are only worth the investment if you are doing a lot of work with hard types of stone.
String lines are a lengthy subject that have their own section to cover them in detail. They are what they sound like, pieces of string that when tied taught, and properly used, provide a guide to build to. Masonry string is the preferred line to use. It is very tough, affordable, and is available from most hardware stores in a variety of bright colors, which help to make the lines stand out. Rebar stakes or wooden supports called batter frames are two of the most commonly used types of supports. Metal pins that can be inserted between stones in a wall that is being repaired are also common.
Other tools that are good to have when building include a tape measure and level, which are most useful when laying out a new wall. A wide range of pry bars, from 3 feet to 6 or more feet in length are particularly useful when dealing with stones that are too large to lift. In addition to the pry bars, having wooden blocks to use as fulcrums and temporary wedges can be very helpful.
Professional wallers may also use diamond saws and grinders to cut or shape stones that would be difficult to shape with a hammer or chisel. Professionals also use hammer drills to create holes for feathers and wedges, which are used to precisely split large stones.
Thank you for taking the time to read about how to properly build dry stone walls!