Do-It-Yourself Stone Work
How to build a Dry Stone Patio
A dry stone patio is an attractive and permanent fixture of your home. With a few minor variations, its construction today is the same as in antiquity. The project will not be difficult in technical ways, but it will be taxing, in terms of the physical labor.
The first step to building a dry stone patio is to develop a plan. A good plan will help you order the right amount of material and to communicate with anyone who is helping you. Grid paper works great, or if you prefer to use a CAD program, we recommend Google Sketchup. To get a sense of what size you want; think of how you will use it, consider what furniture you want to place on it and be sure to leave plenty of room around that furniture so that your guests are not cramped. Draw the plan in your yard with hoses or marking paint and move the furniture into the space. Try it out, see if it is comfortable and well spaced.
There are many options for a design. In designing a patio, feel free to seek inspiration from popular DIY TV shows like Rock Solid and also look to the Old World designs of Italy, Portugal and experiment by considering with designs of the far east, such as Japan. The patio itself could have a rectangular shape, or an organic, kidney bean shape. The stones themselves can be irregular or rectangular. If you are using pattern stones, you could use a predictable pattern, such as herringbone or a random pattern. To get some ideas of which stones to use, take a look at our bluestone, pavers and irregular flagging pages. Come by our stone yard to look through what we have.
- Excavate the area
- Spread and compact crushed stone
- Spread and compact sand
- Lay stones
- Finishing Touches
Excavate the Area
The first step in building a dry stone patio will be to excavate the area where the patio will be so that it is level and deep enough to hold the crushed stone, sand and stone.
6" of crushed stone, 3" of sand and 1.5" of stone pavers = 10.5" deep
You may be dealing with a lot of material in this step. In our project, because the yard was pitched, we will need to remove around 25 yards of loam. To save money on transporting fill, and to we moved some of the loam to a part of the yard where we wanted a burm. Your plans will come in handy when communicating with the excavator. Be confident and clear about what you want done, because you get one chance to do this step right - when the equipment is gone, it's gone. Using marker stakes and paint will help the excavator see the shape of your patio.
Spread and Compact Crushed Stone
When ordering crushed stone and sand, choose a reputable company which is close to your home, as delivery charges escalate with distance from the site. If you multiply length (in feet) x width (in feet) x height (in feet), you will get the area in cubic feet. Divide by 27 and round off to the closest whole number to get the cubic yards of material that you need to order. In our example, we need 6 inches of crushed stone. 20'x20'x0.5' = 200 cubic feet/27 = 7.4, rounded up to 8 cubic yards. We also need to order 3 inches of sand. 20'x20'x0.25' = 100 cubic feet/27 - 3.7, rounded to 4 cubic yards.
Tip: Why not just put the pavers on the loam? Well, you can do that, but it's not recommended. Here's a few key reasons why:
- loam is difficult to level - the organic materials and clay hold it together, so you cannot just rearrange the loam to create a level surface.
- Loam "bounces" - after you lay a paver, you will want to tap it down with a mallet and sand/crushed stone absorbs the impact, while loam springs back from the hammer blows.
- Loam compresses as the organic material decomposes, which, over time can lead to an uneven surface.
- Loam retains water which will freeze and move the stones up and down. Over time, these frost-heaves can make a patio uneven.
Tip: If your project may include electrical features, like a fish pond or lighting, this is the time to run some electrical wire through pvc under your patio - just bury it in the sand.
This is the stage where the mason in you can really shine. The large machinery is gone and there's still a lot of work to do, but you're really just playing in a big sand box at this point. A note on safety: be careful of your back, fingers and toes while moving the stones around and use safety goggles if you are chipping or grinding stone. The stones themselves can be very heavy. A back brace can help you stay safe. The goal at this point is to lay the stones so that they have even spacing between and are level on their surface, with a gentle taper towards the edge so that water doesn't pool in the middle. A taper of 1/8" per foot is recommended. To measure for level, you will need a hard-toothed rake, mason's string, two stakes and a line level. To get a tight and level line, hammer in one stake and tie the line to that stake. Run the line to the other side and when you are basically in the right spot, tie the line to the other stake, then hammer that in while you pull it tight. Our project involved a rectangular shape, so we started in the corner and worked our way out from there. We needed a way to make sure we were building square, so we started by establishing a reference line with stakes and more mason's line. Then, we established the "square line" which was positioned at a right angle to the reference line. Since a carpenter's square is too small to see square at this scale, we used the old 3, 4, 5 right triangle trick. Basically, a right triangle with a 3 foot side and a 4 foot side will have a 5 foot diagonal. Place the square line by rotating it in such a way that a 5 foot diagonal forms a triangle with the two sides at 3 feet and 4 feet
Now, you can finally begin laying stones. People, young and old may be interested in helping, so ask a few friends. Pick up a stone, carry it to the area, lay it down and hammer it in place with a rubber mallet.
Check the stone with a level to see that it is flat (with a gentle taper) and even with adjacent stones. Make adjustments to height with sand. Stand on the stone and rock back and forth. Does it wiggle? If so, adjust the sand by lifting it and putting sand in the requisite areas. Another trick; if the edge that needs sand is exposed, you can wedge sand under the stone by driving the handle of your hammer at the sand near the edge. Repeat again and again. Take breaks, step back and look at your work from a distance. If you need to cut or shape stones, the procedure will depend on the variety of stone used. Bluestone cuts nicely with a diamond blade on a circular saw or angle grinder. Granite will require some heavy hitting with a hammer and chisel to score a line and eventually break the piece at the desired location.
Our project was done with a random size, multi-color bluestone and a cobblestone border on two sides. During excavation we uncovered a lot of fieldstones, so we used those as a retainer wall on the other two sides. Once the stones are laid, level, solid and flat, you can fill the cracks with sand. Mason's sand works fine, but Polymeric Sand (available at AStone) contains polymers which will bind the sand once it becomes wet - it's similar to grout. The advantage with polymeric sand is that it is more permanent and does a good job of preventing weeds. At this point, you have a patio. A little landscaping is customary around the patio to create a transition from lawn to patio. Here is the finished product (picture taken in the late fall.)