How to Build a Sandset Flagstone Patio Part 3 of 3
Sandset flagstone patios blend nicely with natural landscapes. Although flagstone evokes a natural feel, the patio can appear rustic or formal. This patio has clean, well-tamped joints and straight, groomed edges along the perimeter that lends to a formal feel. Plantings in the joints or a rough, natural perimeter would give the same patio a more relaxed, rustic feel.
Overview
Flagstones make a great, long-lasting patio surface with a naturally rough texture and a perfectly imperfect look and finish. Randomly shaped stones are especially suited to patios with curved borders, but they can also be cut to form straight lines. Your patio will appear more at home in your landscape if the flagstones you choose are of the same stone species as other stones in the area. For example, if your gravel paths and walls are made from a local buff limestone, look for the same material in limestone flags.
Flagstones usually come in large slabs, sold as flagstone, or in smaller pieces (typically 16" or smaller), sold as steppers. You can make a patio out of either. Larger stones will make a solid patio with a more even surface, but the bigger ones can require three strong people to position, and large stones are hard to cut and fit tightly. If your soil drains well and is stable, flagstones can be laid on nothing more than a layer of sand. However, if you have unstable clay soil that becomes soft when wet, start with a 4"-thick foundation of compactable gravel under your sand.
There are a few different options for filling the spaces between flagstones. One popular treatment is to plant them with low-growing perennials suited to crevice culture. For best results, use sand-based soil between flagstones when planting. Also, stick to very small plants that can withstand foot traffic. If you prefer not to have a planted patio, simply fill the joints with sand or fine gravel—just be sure to add landscape fabric under your sand base to discourage weed growth.
The following project includes steps for building a classic flagstone patio. You’ll also find instructions for building low dry stone walls, the ultimate add-on to a stone patio surface. If you’re new to working with natural stone, see Cutting Stone for some basic cutting tips.
From: Complete Guide to Patios & Walkways, 978-1-58923-481-9
Step 1
How to Build a Dry Stone Wall
Mortar the capstones to the top of the wall, keeping the mortar at least 6" from the edges so it’s not visible. Push the capstones together and mortar the cracks in between. Brush off dried excess mortar with a stiff-bristle brush. Add patio, if desired (see Sandset Flagstone Patio).
Step 2
Cutting Stone
Step 3
Cutting Stone with a Circular Saw
A circular saw lets you precut stones with broad surfaces with greater control and accuracy than most people can achieve with a chisel. It’s a noisy tool, so wear earplugs, along with a dust mask and safety goggles. Install a toothless masonry blade on your saw and start out with the blade set to cut 1⁄8" deep. (Make sure the blade is designed for the material you’re cutting. Some masonry blades are designed for hard materials like concrete, marble, and granite. Others are for soft materials, like concrete block, brick, flagstone, and limestone.) Wet the stone before cutting to help control dust, then make three passes, setting the blade 1⁄8" deeper with each pass. Repeat the process on the other side. A thin piece of wood under the saw protects the saw foot from rough masonry surfaces. Remember: always use a GFCI outlet or extension cord when using power tools outdoors.
Step 4
How to Cut Flagstone
Mark the stone for cutting on both sides using chalk or a crayon. If there is a fissure nearby, mark your line there, since the stone will likely break there naturally. Note: To prevent unpredicted breaks when cutting off large pieces, plan to chip off small sections at a time.
Step 5
How to Cut Flagstone
Score along the cut line on the backside of the stone (the side that won’t be exposed) by moving a stone chisel along the line and striking it with moderate blows with a maul. As an alternative, you can do this step with a circular saw.
Step 6
How to Cut Flagstone
Break the stone to complete the cut: first, turn the stone over and rest it on a metal pipe or a 2 x 4 so the scored edge is directly over the support. Then, strike forcefully near the end of the waste portion to break the stone along the cut line.
Step 7
Dressing Stones for Walls
Laying stones works best when the sides (including the top and bottom) are roughly square. If a side is sharply skewed, score and split it with a pitching chisel, and chip off smaller peaks with a pointing chisel or mason’s hammer. Remember: a stone should sit flat on its bottom or top side without much rocking.
Step 8
Dressing Stones for Walls
“Dress” a stone using a pointing chisel and maul to remove jagged edges or undesirable bumps. Position the chisel at a 30 to 45º angle at the base of the piece to be removed. Tap lightly all around the break line, then more forcefully, to chip off the piece. Position the chisel carefully before each blow with the maul.
