Types of Bluestone Patios

Types of Bluestone Patios

A question that often comes up when discussing bluestone patios are the different varieties of bluestone pavers. To the untrained eye they may all look the same, but, there are actually a number of differences that effect the cost, appearance, and installation methods.

Natural Cleft Bluestone:

Natural cleft bluestone describes bluestone that has been split into layers during the quarrying process. Bluestone is a sedimentary stone, meaning that is comes from sediment that has been fused together over time from the enormous weight and pressure from above.  Natural cleft bluestone is formed closer to the surface of the earth than other bluestone.  Without as much pressure on the stone, lines of de-lamination or horizontal cracks form which make it easy to split into layers.  These layers are then cut into rectangles to make the bluestone pavers you see today.

As it is naturally split, the bluestone pavers have some irregularities.  The surface of the stone will have more bumps and texture, and each stone will have somewhat varyied thickness.  Natural cleft bluestone also tends to have a range of colors from blue, gray, purple, and rusty orange.

Although the quarrying process takes less machining and makes natural cleft bluestone less expensive than other bluestone, the varied thickness and irregular surface makes it more labor intensive to install.

natural cleft bluestone

natural cleft bluestone

Natural Cleft Bluestone

Natural Cleft Bluestone

 

Thermal Bluestone:

Thermal bluestone is formed deeper within in the earth.  With more weight and pressure above, the stone is solid and must be broken off in chunks and then saw cut into layers.  The saw cut leaves a very smooth, unnatural surface which then must be re-textured.  This is the ‘thermaling’ process which gives its name.  The stone is wet down and then heated with a super hot flame until the surface flakes off, exposing the natural roughness of the stone.

Thermal bluestone is more expensive to produce, but, the stone is almost perfectly uniform in thickness. This makes the installation and leveling process less labor intensive.

Thermal bluestone then comes in three different color varieties, full color, regular, and true blue.

Full Color Thermal Bluestone:

Full color thermal bluestone is less common and slightly less available.  It is thermal cut stone but still has a ranger of blues, grays, and purples.  The colors will not be as pronounced as Natural Cleft Bluestone, but more so than other thermal bluestones.

Regular Thermal Bluestone:

Regular Thermal Bluestone is most common.  It will come in a mild range of blues and grays.

Thermal Bluestone Patio

Thermal Bluestone Patio

“True Blue” Thermal Bluestone

“True Blue” Bluestone has been hand picked and sorted so that all of the stones are identical in color.

Thermal Bluestone Patio

True Blue Thermal Bluestone Patio

Irregular Bluestone

Irregular bluestone, also called “stand-up bluestone” or “flagstone” is naturally cleft bluestone that has not been cut into rectangles.  Irregular bluestone is sold by the ton instead of by the square foot and is generally cheaper in cost, but, much more labor intensive to install.

Irregular bluestones will vary greatly in shape, size, and thickness.  Depending on the desired look, they need to be cut and shaped to fit together, and leveled one by one.

Irregular Bluestone Patio

 

Flagstone/Bluestone Patio – Lincoln, MA

Rebuilding a Flagstone Patio in Lincoln, MA

At this home in Lincoln, MA the existing flagstone patio was badly overgrown and out of level.  The original flagstone patio had apparently been laid directly on the soil with wide joints.  Being it a sunny area, weeds grew rampant and the patio had deteriorated considerably.

IMG_1059

Original Flagstone Patio – Lincoln, MA

Flagstone Patio Lincoln, MA - Before

Original Flagstone Patio – Lincoln, MA

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Original Flagstone Patio – Lincoln, MA

 

To solve this problem the plan was to take up the existing flagstone, excavate the soil, lay weed block fabric, base material, and re-lay the patio with 1/2″ joints.

In order to achieve tight joints the stones must be cut and pieced together.  It is a labor intensive process but the results are attractive and potentially make it harder for weeds to take root.  To make up the difference in area that we lose with tighter joints and cutting waste, we purchased a couple additional pallet of Irregular Bluestone to match the existing patio flagstones.  The larger section of the patio is made up of the existing flagstones, the smaller portion of patio beneath the Japanese Maple is made up of the new flagstone that we would usually use.

Assembling the Flagstone Patio - Lincoln, MA

Assembling the Flagstone Patio – Lincoln, MA

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Assembling the Flagstone Patio – Lincoln, MA

 

The base material consists of ~4″ gravel and ~2″ of stone dust.  The gravel base is sturdy and drains well, the stone dust (fine crushed up stone) is workable and lets us level each stone.  Gravity holds everything in place while the patio remains flexible to minor movements in the ground.  This method is more cost effective than cementing the patio stones and there is no risk of visual cracks in the cement if things eventually shift.

The flagstone patio is complete in time to enjoy a lovely autumn in New England:

Flagstone Patio - Lincoln, MA

Flagstone Patio – Lincoln, MA

Flagstone Patio - Lincoln ,MA

Flagstone Patio – Lincoln ,MA

Flagstone Patio - Lincoln, MA

Flagstone Patio – Lincoln, MA

Flagstone Patio - Lincoln, MA

Flagstone Patio – Lincoln, MA

Flagstone Patio - Lincoln, MA

Flagstone Patio – Lincoln, MA

 

 

 

Irregular Bluestone Patio – Marlborough, MA

At his home in Marlborough, MA an old concrete patio had shifted and cracked and was pitching water towards the house.  Knowing something had to be done, the homeowners decided this was a great opportunity to liven up their outdoor space with a new and improved patio.

existing concrete patio.  windows boarded in preparation for demo

existing concrete patio. windows boarded in preparation for demo

existing paito

existing patio

We remove the concrete with a machine and then proceed to dig out the base for the patio.  The granite step is saved to be used for the new patio, and plenty of stones come out of the ground that we save for the upcoming fieldstone wall.

concrete removed

concrete removed

For the steps we purchase some additional granite.  We picked out antique granite steps to match the existing one and also some additional fieldstone for the walls.  Next we set the steps in place, fill the patio base, and set our base stones for the raised bluestone patio.

patio fill and granite steps

patio fill and granite steps

Next we build the wall that will run one side of the patio.  We use stones that came out of the ground and some supplemental fieldstone from the stoneyard.  The client is looking for a quaint, farm house wall with rounded stones.

fieldstone wall

fieldstone wall

Fieldstone Wall

Fieldstone Wall

Wall and Steps complete

Wall and Steps complete

After the wall and steps are set – we fill in the rest with irregular bluestone.  Irregular bluestone makes a nice patio.  There are many different ways to fit and cut the stones.  We try to fit the stones fairly tight without letting it look like we made the cuts.  This gives it a consistent but natural/authentic look.

Irregular bluestone patio

Irregular bluestone patio

Bluestone patio, fieldstone wall, granite steps

Bluestone patio, fieldstone wall, granite steps

The following season a new patio door goes in, and some plantings and patio furniture bring it all together.

new patio with furniture

new patio with furniture

Patio with furniture

Patio with furniture