All Types of Flagstones

This lighter-colored flagstone walkway has been set on a sand bed with soil between the stones.

Flagstone is any type of smooth flat stone, generally 1 to 3 inches thick. Flagstones can be natural and irregularly shaped or they can be cut from a quarry in regular square or rectangular patterns. They can be of a variety of rock but most often are some form of sandstone, slate or limestone because these lend themselves to thin slabs with fairly smooth surfaces. Flagstone is used for paving patios, walks, porches, pool surrounds and other outdoor surfaces.

Set Flagstones in Sand or Mortar

Regardless of the stone type, flagstones are usually set in a bed of sand or mortar, although some flagstone walkways are formed by setting individual stones in dirt, with grass in between the stones. They should be set on a solid base, however, to prevent awkward pressures that could cause them to fracture.

Western Mountain Stones

Much flagstone comes from Western mountain regions. Styles called quartzite, Bitterroot, Iron Mountain, Three Rivers, Camas and Molalla all come from Idaho, Montana, Utah or Oregon. They vary in color from white, through gray and silver to brown, green and red. Some varieties have swirling color patterns. They vary in hardness and size -- some, such as Camas, lend themselves to big stepping stones in yards.

Pennsylvania and Tennessee Types

Many eastern flagstones come from Pennsylvania and Tennessee mountain regions. Most of the Pennsylvania styles, in varying colors, come in naturally irregular shapes, which lend themselves to stepping stones, walkways or specially designed patios. Some, like Tennessee Crab Orchard, come in thin or thick versions and usually are quarried and cut in regular shapes. Colors run to browns, reds and blues or combinations thereof.

Flagstone Sells by the Ton

Flagstone costs vary widely, with availability to supply a key factor. Flagstone is usually sold by the ton -- thicker stones will cost more, but those 2 inches or more thick can be laid in sand beds, while thinner slabs will need to be set in more expensive mortar. Shape plays a part in the cost because of coverage -- irregular shapes will have to be adjusted to fit regular boundaries such as patio edges, and the result may be wasted pieces of cut-off stone.

References

• Paversearch: Flagstone pavers
• Free Dictionary: Flagstone
• Tramway Stone: Flagstones
• Pacific Stonescape: Flagstone