Patio

An outdoor space generally used for dining or recreation that adjoins a residence and is typically paved. It may refer to a roofless inner courtyard of the sort found in Spanish-style dwellings or a paved area between a residence and a garden.

 

At Statements In Stone “We Create Warm and Friendly Spaces.”

Patios in the Raleigh area are most commonly constructed from paving slabs, paving flags, or pavers. There are two main types of paving slab; concrete or stone. Concrete slabs are cheaper than their natural stone counterparts. This is because the cost of production is far lower, as well as life expectancy compared to natural stone. Concrete slabs are produced solely within a manufacturing plant unlike natural stone which is extracted from quarries.

As well as paving slabs, patios can also be created using other durable surfaces such as bricks, block paving, tile, concrete, natural paving stones or cobbles.

 

Pennsylvania Bluestone

is a layered sandstone found only in the northeastern tier of Pennsylvania, parts of northern New Jersey and the southern tier of New York. The quarried product has many uses, from cut dimensional stone used in patios, walkways and stair treads to architectural stone used in buildings. It is also used for wallstone, decorative boulders, natural steps and other landscape and hardscape features. The name Pennsylvania Bluestone is due to its predominantly blue color and because the majority of stone is quarried in Pennsylvania; it can, however, appear in many other hues besides blue. It was formed over 360,000,000 years ago during the Devonian Period as large inland seas deposited sand in the Catskill delta region. It is composed of feldspar, sand, and mica (among other minerals) and is clear of most organic residues.

The commercial refinishing process for bluestone cut slabs is called spalling. This process incorporates water and heat to reveal the natural layers of the stone as it was deposited originally. The cutting orientation must be almost exactly along the horizontal layers. The cut slab surface is soaked with water and heated rapidly with a wide nozzle propane torch, breaking off chips of stone along their natural fault lines. The spalled slabs are called Pennsylvania River Rock or variations of this name depending on the market or origin of the stone.

If the initial deposit was made under slow moving water the ripples of the water action on the sand or mud will be revealed. This deposition process may be seen today at any ocean beach in shallow water or in a stream bed where conditions allow it to be observed.

 

Flagstone (flag)

is a generic flat stone, usually used for paving slabs or walkways, patios, fences and roofing. It may be used for memorials, headstones, facades and other constructions. The name derives from Middle English flagge meaning turf, perhaps from Old Norse flaga meaning slab or chip.
House on Westray, Orkney, with flagstone roof

Flagstone is a sedimentary rock that is split into layers along bedding planes. Flagstone is usually a form of a sandstone composed of feldspar and quartz and is arenaceous in grain size (0.16 mm – 2 mm in diameter). The material that binds flagstone is usually composed of silica, calcite, or iron oxide. The rock color usually comes from these cementing materials. Typical flagstone colors are red, blue, and buff, though exotic colors exist.

Flagstone is quarried in places with bedded sedimentary rocks with fissile bedding planes. Examples include Arizona flagstone and Pennsylvania Bluestone.
Lauze stone in Lannion (Brittany)

Around the thirteenth century, the ceilings, walls and floors in European architecture became more ornate. Anglo-Saxons in particular used flagstones as flooring materials in the interior rooms of castles and other structures. Lindisfarne Castle in England and Muchalls Castle (14th century) in Scotland are among many examples of buildings with surviving flagstone floors.

 

Pavers

Interlocking concrete pavements or pavers are a special dry mix pre-cast piece of concrete commonly used in exterior hardscaping pavement applications. Unit Pavements or block paving, nicknamed pavers in the United States were developed before the Second World War by the Dutch and introduced into the United States in the early 1970s.

Interlocking paving stones are installed over a compacted stone sub-base and a leveling bed of sand. Concrete paving stones can be used for walkways, patios, pool decks and driveways and airport or loading docks.

Instead of connecting the pavers by pouring grout between the joints as one would with tiles, sand particles are spread over the pavers and tamped down. The sand stabilizes the interlocking pavers, yet allows for some flexibility. This type of pavement will absorb stress such as small earthquakes, freezes and thaws, and slight ground erosion by flexing. Therefore, they do not easily crack, break or buckle like poured asphalt or poured concrete.

Some of the special tools needed for installing interlocking pavers are vibrating compaction machine or “Vibra Plate” and Shear Cutter. The former is used to compact the base material to 90% density minimum and also to set and interlock the pavers into the sand bed. The latter is used to cut the pieces to fit at corners and edges. The sand does not easily wash out with rain or garden hose water. Polymeric Sand or a sealant can be used to further lock or coagulate the sand. There are many other tools involved in preparing sub-grade, base materials, sand bed and installing unit pavements correctly.

Standard thicknesses are 60mm (for light traffic) and 80mm (heavy traffic). 50mm too is common in some countries like Pakistan (used for footpaths etc.).

Benefits of paver over asphalt and poured concrete include high compressive strengths (7000+psi as per BS and 8000+psi with no more than 5% absorption as per ASTM codes and as high as 19,000+psi depending on manufacturer and type of unit pavement), pleasant look, time saving, easy removal and relaying.

 

Hardscaping

Typical small-scale hardscaping examples include patios and sidewalks. Retaining walls are often used to create boundaries between hardscapes and earth landscaping features, or softscapes. From an urban planning perspective, hardscapes can include very large features, such as paved roads and traffic circles or traffic islands. Most artificial water features are technically hardscapes because they require a barrier to retain the water, instead of letting it drain into the surrounding soil.

From an aesthetic perspective, hardscaping allows workers to erect landscaping features that would otherwise be impossible due to soil erosion, or that compensate for large amounts of human traffic that would cause wear on bare earth or grass. For example, sheer vertical features are possible.

Hardscape means any area devoted to a landscape made up of hard wearing materials such as stone, concrete and other construction materials, as opposed to soft landscaping which is grass, bark

and other such items.