Shade sail
Encyclopedia
A shade sail is a device to create outdoor shade based on the basic technology as a ship's sail. Shade sails use a flexible membrane tensioned between several anchor points. While generally installed permanently, they are cheap and easy to set up. They are usually provided above public gathering places such as seating areas and playgrounds in countries where strong sun radiation makes prolonged stays in the open sun unpleasant or dangerous due to sunburn and skin cancer risk.
ians and later the Greeks
and Romans
used large pieces of fabric to provide shade. The Colosseum
in Rome
was shaded with large canvas "sails" pulled into place by Roman sailors. Modern shade sails came into wider use with the invention of a far more durable and relatively inexpensive fabric called shade cloth. Useful versions of shade cloth appeared in the early 1990s especially in Australia
and South Africa
.
For most of the 1990s there was some confusion about what these new devices should be called however they are now most commonly called shade sails throughout Australia, South Africa and the U.S.A. Shade sails have yet to have a significant impact in Europe
and South America
. A number of Australian shade sail businesses export to other countries. Rapid growth in the "shade sail industry" has seen many new businesses and websites offering shade sails and shade structures.
degradation. UV inhibitors are now added during the manufacture of shade cloth and good shade cloth now generally comes with a multi-year UV degradation warranties
. Shade cloth is a knitted fabric
and this is an important factor in using it to design and manufacture shade sails.
Successful shade sail design uses the inherent "stretch" of the knitted fabric
to create three dimensional shapes. Fabrics other than shade cloth are used to make shade sails such as PVC
, a more expensive alternative, or canvas
variations. The low cost of shade cloth and its ability to breathe makes it a prime choice for "cool shade".
or a pulley
system fixed at each corner of the sail. For permanently fixed sails, the turnbuckle provides the best means of fixing the canopy since it generally allows more tension to be applied. For sails that are used on an occasional bases, the pulley system is more practical since it can be set up and taken down in a couple of minutes.
For domestic applications of shade sails it is recommended to install them with a quick release "snap hook" at each corner. This allows the sail shade to be quickly taken down in high wind conditions or during the winter season. Correct installation requires that adequate and quite considerable tension be applied to the sail to allow it to adopt it's correct shape and prevent flapping in the wind. It is important to ensure that the mounting points are substantial and secure both to be able to accept the required initial tension and to absorb the loads created by wind gusts hitting the sail.
History
Ancient EgyptAncient Egypt
Ancient Egypt was an ancient civilization of Northeastern Africa, concentrated along the lower reaches of the Nile River in what is now the modern country of Egypt. Egyptian civilization coalesced around 3150 BC with the political unification of Upper and Lower Egypt under the first pharaoh...
ians and later the Greeks
Ancient Greece
Ancient Greece is a civilization belonging to a period of Greek history that lasted from the Archaic period of the 8th to 6th centuries BC to the end of antiquity. Immediately following this period was the beginning of the Early Middle Ages and the Byzantine era. Included in Ancient Greece is the...
and Romans
Ancient Rome
Ancient Rome was a thriving civilization that grew on the Italian Peninsula as early as the 8th century BC. Located along the Mediterranean Sea and centered on the city of Rome, it expanded to one of the largest empires in the ancient world....
used large pieces of fabric to provide shade. The Colosseum
Colosseum
The Colosseum, or the Coliseum, originally the Flavian Amphitheatre , is an elliptical amphitheatre in the centre of the city of Rome, Italy, the largest ever built in the Roman Empire...
in Rome
Rome
Rome is the capital of Italy and the country's largest and most populated city and comune, with over 2.7 million residents in . The city is located in the central-western portion of the Italian Peninsula, on the Tiber River within the Lazio region of Italy.Rome's history spans two and a half...
was shaded with large canvas "sails" pulled into place by Roman sailors. Modern shade sails came into wider use with the invention of a far more durable and relatively inexpensive fabric called shade cloth. Useful versions of shade cloth appeared in the early 1990s especially in Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
and South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
.
For most of the 1990s there was some confusion about what these new devices should be called however they are now most commonly called shade sails throughout Australia, South Africa and the U.S.A. Shade sails have yet to have a significant impact in Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
and South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
. A number of Australian shade sail businesses export to other countries. Rapid growth in the "shade sail industry" has seen many new businesses and websites offering shade sails and shade structures.
Current technology
Originally shade fabric, like all fabrics in the outdoors, suffered from UVUltraviolet
Ultraviolet light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than X-rays, in the range 10 nm to 400 nm, and energies from 3 eV to 124 eV...
degradation. UV inhibitors are now added during the manufacture of shade cloth and good shade cloth now generally comes with a multi-year UV degradation warranties
Warranty
In business and legal transactions, a warranty is an assurance by one party to the other party that specific facts or conditions are true or will happen; the other party is permitted to rely on that assurance and seek some type of remedy if it is not true or followed.In real estate transactions, a...
. Shade cloth is a knitted fabric
Knitted fabric
Knitted fabrics is the third major class of fabric, after woven and nonwoven fabrics.-Elasticity, thickness and warmth:Compared to the other two classes, knitted fabrics are much more elastic, which accounts for their historical use in stockings and other clothing that requires changes in shape...
and this is an important factor in using it to design and manufacture shade sails.
Successful shade sail design uses the inherent "stretch" of the knitted fabric
Fabric
A fabric is a textile material, short for "textile fabric".Fabric may also refer to:*Fabric , the spatial and geometric configuration of elements within a rock*Fabric , a nightclub in London, England...
to create three dimensional shapes. Fabrics other than shade cloth are used to make shade sails such as PVC
PVC
Polyvinyl chloride is a plastic.PVC may also refer to:*Param Vir Chakra, India's highest military honor*Peripheral venous catheter, a small, flexible tube placed into a peripheral vein in order to administer medication or fluids...
, a more expensive alternative, or canvas
Canvas
Canvas is an extremely heavy-duty plain-woven fabric used for making sails, tents, marquees, backpacks, and other items for which sturdiness is required. It is also popularly used by artists as a painting surface, typically stretched across a wooden frame...
variations. The low cost of shade cloth and its ability to breathe makes it a prime choice for "cool shade".
Installation
Modern purpose-made shade sails vary in shape, size and color and there is trend towards installing multiple sails, sometimes overlapping, thereby adding some form and style to its function. Shade sails are tensioned usually by means of either a stainless steel turnbuckleTurnbuckle
A turnbuckle, stretching screw or bottlescrew is a device for adjusting the tension or length of ropes, cables, tie rods, and other tensioning systems. It normally consists of two threaded eyelets, one screwed into each end of a small metal frame, one with a left-hand thread and the other with a...
or a pulley
Pulley
A pulley, also called a sheave or a drum, is a mechanism composed of a wheel on an axle or shaft that may have a groove between two flanges around its circumference. A rope, cable, belt, or chain usually runs over the wheel and inside the groove, if present...
system fixed at each corner of the sail. For permanently fixed sails, the turnbuckle provides the best means of fixing the canopy since it generally allows more tension to be applied. For sails that are used on an occasional bases, the pulley system is more practical since it can be set up and taken down in a couple of minutes.
For domestic applications of shade sails it is recommended to install them with a quick release "snap hook" at each corner. This allows the sail shade to be quickly taken down in high wind conditions or during the winter season. Correct installation requires that adequate and quite considerable tension be applied to the sail to allow it to adopt it's correct shape and prevent flapping in the wind. It is important to ensure that the mounting points are substantial and secure both to be able to accept the required initial tension and to absorb the loads created by wind gusts hitting the sail.