Hardscaping with Flagstone

Flagstone is a generic description of flat stone that is most often used in building and landscaping.  It is a sedimentary stone that can be split into thin layers, allowing it to be used in many applications.  Flagstone is usually a sand stone and contains feldspar and quartz.  Most people recognize flagstone by its split-surface and uneven border, giving it a natural look.


Flagstone comes in a variety of colors and sizes and its irregular design gives flagstone a unique appearance.

Flagstone typically ranges in thickness from 0.5 to 2 inches.  Many experts recommend a thickness of at least 1 inch for surfaces that require weight or will sustain wear, such as those that people will walk or sit.  The slabs usually are cut or broken into irregular shapes.


There are several advantages of flagstone:

  • The earthy hues of flagstone give it a natural look.
  • Flagstone is durable with a non-slip surface.
  • Flagstone can be laid dry for a permeable surface.
  • Hardy ground cover, moss or grass can be grown between the stones.  Growing plants between the small openings of flagstone will soften the look of the stone.  Examples include various types of thyme, Baby Tears, dichondra, mint and moss.


Patios and Terraces

Flagstone is one of the best materials to use for patios because of its narrowly packed joints that allow water to permeate rather than running off.  Due to their shape and earthy shades of browns, reds, grays and blues, use of flagstone for patios give a very natural, organic look.

The most common types of flagstone used for paving patios are sandstone, slate and limestone.

Also, flagstone can be used to create a formal or informal patio.  Using cut stones in a repeating pattern will give your patio a more formal look while irregular stones laid randomly will create a more informal look.

Walkways and Stepping Stones

The natural nonslip textured surface of flagstone make it a good choice for walkways.

There are several flagstone walkway design options:

Straight Layout

Place cut flagstones in an offset rectangular pattern.  This will create a formal-looking walkway.

Curved Layout

The natural shape of flagstone will create a more casual look to a walkway.  To define the edges, cut the stone or shape them to curve.


Using flagstone in its original form, without cutting or shaping, creates a more natural look.  The stones should be placed far apart with ground cover in between.  This will allow the stones to integrate nicely with the landscape.


Utilizing the array of earthy colors of flagstone and accentuating those characteristics will make a walkway the focal point of the garden.


Flagstone set with a mixture of cement, sand and water is called mortared flagstone.  When using mortared flagstone, the stones are set securely in place creating a smooth, even walking surface.

Dry Laid

Flagstones do not have to be mortared.  They can be placed on a prepared subbase of dirt or compacted gravel and sand.  Compared to mortared flagstone, this option is more cost-effective.


Flagstone’s durability and maintenance-free qualities make it an excellent material for landscaping.  And, adding flagstone steppingstones to your landscape can be an easy do-it-yourself weekend project:

1-  Set the borders of your path with a garden hose.  To add interest, create a winding effect.

2-  Hammer stakes into the ground along the desired edge.  Mark a spot on each stake 1/4″ above the ground.

3-  Tie string from stake to stake.  Be sure the line level of the string is level.

4-  Remove any grass between the stakes.

5-  Dig soil to an even depth of 2.5″ from the ground to the string.  You will want to allow for your run-off slope, if needed.  Once the depth is reached, tamper the soil to make it even.

6-  Spread sand 1.5″ thick on the bottom.  A 2×4 will help to level the sand and make it smooth.

7-  Lay the flagstone on the sand.  You will want to turn and piece together.  Depending on the thickness of the each stone, you may need to add or remove sand as needed.

8-  Set each flagstone by tapping it down with a rubber mallet.  To protect the stone, use a 2×4 between the stone and mallet.  The 2×4 will also help to ensure that the walkway is even.

9-  Add sand to the pathway and sweep into the cracks to “cement” the pieces.  Follow-up with a light watering.  You will want to repeat this step until all pieces are firmly in place.

10- Fill in spaces around the stone with dirt, mulch, gravel or smaller pieces of flagstone.