An OC Guide to Retractable Awnings
A retractable awning can be used to convert a patio into an outdoor living space. In this guide, we will look at the different retractable awnings you can buy, the parts that make up such an awning, and a whole lot more besides.
This awning is considered a domestic awning because it is usually designed to be installed in houses, though it can also be fitted on shops and hotels so as to shade their patios (from sunlight) and convert them into usable waiting space or eating place respectively.
A Little bit of history
The first awnings in recorded history were the woven mats that were placed on top of market stalls to provide shade in Ancient Egypt.
Also, a woven mat could be placed on protruding beams above the door to provide shade for visitors or anyone standing outside the door.
Later, the Greeks used awnings covered with linen to shade their theaters.
This was later improved on by the Romans who built an awning that could be extended to cover the cavea of the Colosseum, and after the spectators had left, the awning could be pulled back, hence becoming the first large-scale retractable awning, and it was called the Velarium.
This Velarium was designed to produce a ventilation updraft that facilitated air circulation and allowed a cool breeze to waft through the spectator space.
Much improvement in awning design occurred in the 19th century when posts (made of iron or timber) were set on the edge of the sidewalk, and rafters set on the posts, with the other end of the rafters being attached to the building façade.
A canvas secured to the façade was draped over the rafters, with its edge hanging down the edge of the roof to become a valance that covered the top section of the posts.
Also, this valance concealed the top bar that connected the posts to the rafters. This canvas could be rolled up or removed when required.
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The modern patio awning
The modern patio awning is a product of the new world. The industrialization of America and the invention of the steamship compelled sailmakers and canvas mills to look for new market opportunities, and they found one in the manufacture of awnings.
This laid the foundation for the awning industry. It also obligated existing awning makers to improve the fixed frame awning, as well as led to the introduction of operable awnings that eliminated the need for fixed posts and rafters.
Use of Extension arms
These operable awnings had extension arms securely hinged at their point of attachment to the façade. Therefore, the extension arms could be raised (lifted up) or lowered, and this allowed the awning to be retracted or projected respectively.
The raising/elevating of the extension arms lifted the awning to come rest against the wall and this gradually eliminated the shading provided by the awning. This removal of awning shade – by removing awning coverage – is called retraction.
Likewise, the extension arms could be lowered to increase the amount of shade provided by the awning, and this is called shade projection, or simply awning projection.
These early operable awnings could be raised by pulling ropes or using pulley arrangements to smoothly raise or lower the extension arms.
Evidently, it is called an operable awning because a person could operate it (that is [i.e] raise or lower it) to regulate awning coverage.
The modern operable awning uses strong extension arms and covers, as well as a unique operation design to allow for easy operation and enhancement of façade aesthetics.
Different cover materials
The patio awning usually has a light substructure (or understructure) made of strong lightweight materials such as aluminum, fiberglass, or composite plastic. The engineering design of the understructure can create a truss, planar frame, or space frame.
This substructure is covered by a canvas made of polyester fabric, woven acrylic, or even cotton. Moreover, instead of using a canvas, a transparent sheet, a plastic panel, or any lightweight panel can be used to provide a sheeted cover.
Using hardcover made of sheets or plastic panels is recommended if the awning is expected to withstand a high wind load (due to high wind speeds) and/or snow load.
Still, one can install a patio awning with a soft (fabric) cover in a place that experiences high wind speeds and heavy snowing during winter. This is possible if the cover can be removed, or pulled into a special housing called a cassette.
If the cover is pulled into (or rolled into) its special housing (cassette), then the patio awning is described as retractable.
The Retractable Patio Awning
The retractable patio awning is the latest development in retractable awning design, and it came with 2 unique design features: a waterproof cover, and the capacity to create an outdoor room as is explained later.
Moreover, this retractable awning can withstand wind speeds of up to 63 miles-per-hour(mph) or 101 kilometers-per-hour(kph). Expectedly, the retractable patio awning can be described as an operable domestic awning.
From the aforementioned explanation of the awning structure, it can be deduced that the retractable patio awning is designed to serve 6 main functions which are described below.
As alluded to earlier, the main purpose of the patio awning is to create a livable outdoor space by screening the place from sunshine and rain.
This allows one to place furniture on the shaded patio. Moreover, the shape and design style of the awning can endow it with a capacity to act as a windbreaker, as well as provide cover against raindrops and snowfall.
In some unique models, solar shading is simply achieved by glazing a transparent or translucent cover so that the outdoor space can be illuminated by the sun without exposing the people to the raw intensity of Sundays.
This creates a good sunscreen that is important for people who want to enjoy some solar without being exposed to harmful high-energy Sundays.
The retractable patio awning allows the owner to control awning coverage by either unrolling it to increase coverage, or retracting it to decrease coverage, and this provides for controllable protection from the weather.
For instance, the awning can be unrolled when it starts to shower, or at noon on a sunny day to create shade from the midday sun.
Reduce Fading and Energy Costs
The patio awning creates a cool ambient environment under its cover. Therefore, its users enjoy a relatively cool ambiance during a sunny day, or in basic terms, the awning decreases solar heat gain.
Also, because its shade extends through windows, it ensures that indoor temperatures remain low, and if one uses an air conditioning (AC) unit, then less AC power is consumed to cool the room hence saving on AC costs.
Even the retractable drop arm awning whose canvas rolls down to cover the window can create sufficient shade inside the house (or building) to reduce AC energy consumption.
Indoor furniture and fabrics can fade when exposed to direct sunlight due to direct exposure to ultraviolet (UV) rays, and using a patio awning do reduce this fading.
Waterproofing an Extended Living Area
The patio awning can be used to extend the living area by roofing a patio. Also, adding columns to this (patio) awning converts it to a canopy that allows the living area to be extended to cover a large area of the patio.
Under this awning, a sheltered space is created for children to play. Moreover, the children can play during a light shower.
This is because the patio awning must be waterproof, and must not allow water to seep through it, which allows kids to play without getting wet.
The top of the awning cover can be painted with unique art such as the business emblem, or sign, as well as have the business name and other information, including contact addresses, written on it.
Therefore, painting and writing information on the awning cover allows the patio awning to act as an improvised billboard or signboard.
Creation of an Outdoor Room
As expected, the patio awning is attached to only one wall, the façade. This leaves three potential walls – the front and 2 sidewalls – that can be enclosed.
The enclosure can be achieved using special screens called solar shade screens, and if these screens form the 3 walls, then an outdoor room is created. This outdoor room can be heated in winter, or be cooled by an AC during summer.
Usually, the solar shade screen is a view-through canvas, or mesh fabric, that allows one to see outside but blocks solar UV rays.
Also, in a normal patio, a long free-hanging valance that descends as low as to touch the floor can create a front wall.
Patio awning comes in different styles, and each style adds an aesthetic value to the house or building, as well as the patio and garden.
Now, that the functions of the patio awning have been described, what are the main parts that form a retractable patio awning?
Parts of a Retractable Patio Awning
There are 3 basic parts in a retractable awning: cover, understructure, and propulsion system.
It is the cover that gives the awning its functional value. This means that the frame (or substructure) of the awning on its own (without the cover) does not offer any significant benefit associated with a patio awning. The cover provides the screen against solar rays and rainfall.
Depending on the material of the cover, the patio awning can be left out during a light shower. However, torrential rain can billow the cover if it is made of fabric or canvas, and for this reason, it should be retracted in the event of impending torrential weather.
The awning cover can slope to up to 35º which allows for water to easily flow down. Even so, some models feature a special design that allows for a slope angle of 45º, but this requires strong (or reinforced) extensible arms to hold such a steeply-sloped cover.
Special care is needed when fitting the awning in a building whose roof features a gutter.
- Cotton: This is painted with acrylic paint, or coated with acrylic, so as to make it waterproof.
- Polyester: This is a waterproof material that is resistant to shrinkage and creasing, and affords good UV protection. It is also washable. It can also be coated with acrylic to improve its UV resistance and better adapt it to cool climates.
- Vinyl: This is a waterproof material that can be used in rainy areas with a cool climate. Even so, it has lower UV resistance as compared to polyester, which limits its use in sunny regions. Still, it can be coated with acrylic paint to improve its UV resistance.
- Acrylic: This is a waterproof material that provides better UV resistance than polyester. It is also washable and rot-proof hence it cannot degrade due to continuous exposure to moisture. This makes acrylic a more durable material than polyester.
- Micro-perforated canvas: Both acrylic and polyester fabrics provide poor ventilation, and if ventilation and draught control are needed, then one needs to use a micro-perforated canvas.
Its perforated fabric allows hot air underneath it to exit the covered patio through its pores, and this ascent of hot air creates a low-pressure zone that draws in cool air via convection currents to the patio hence creating a draught that cools the shaded patio.
This canvas is resistant to UV rays and tears, and can even be washed. It is also rot-proof.
This is a substructure that holds the awning cover in place and unrolls (projects) it to increase the shade, and when needed, retracts the cover.
It consists of the mounting brackets that hold the entire patio awning onto the façade, and for this reason, the brackets are described as wall brackets.
Expectedly, the mounting brackets hold the awning housing called the headbox, and its contents in place.
This means that these brackets secure the roller tube, torsion bar, front (valance) bar, arms shoulder, and retractable arms to the wall.
In some models, the motor housing is mounted on these wall brackets. The wall brackets and the components it holds are covered by a protective hood/roof that serves as the top cover of the headbox, and this completes the awning housing to form a cassette.
As expected, this cassette is a casing where the roller tube and retracted fabric, and at times the fully-folded arms are housed.
There are 3 types of cassettes:
Its protective roof covers the mounting bracket, roller tube, and awning fabric when the retractable arms are fully folded. It also covers the fully-folded arms. This cassette allows the awning to be fully closed during full retraction.
This protective roof does not cover the fully-folded arms, and it is also called a semi-cassette.
This is the headbox without the protective roof.
The awning cover is rolled on the roller tube, and this tube is rotated by a propulsion system. Rotating the roller tube unwinds the fabric which will hang if the retractable arms are not extended.
For this reason, unwinding the cover must be coordinated with the extension of the extensible/folding arms. Likewise, retracting the cover by rotating the roller in the opposite direction should be synchronized with folding the arms.
Usually, these retractable arms unfold to extend the cover on a horizontal plane, hence they are called horizontal arms.
In some retractable arms, the individual arms are oriented in an X-style so that they open in a scissor-like or accordion-style manner.
These retractable arms are secured to the torsion bar via arm shoulders. This secures the arms to the headbox. This also allows the arms to carry the valance bar that projects the cover and holds the overhanging valance.
As expected, the rotation of the roller tube is synchronized with the opening of the retractable arms so that the cover can be projected as required.
A minimum of 2 folding arms are needed to extend or project (unroll) the awning cover, and then fold to retract the cover.
The extent that the arms can project the cover from a fully retracted position to a fully-projected position (with the arms now fully extended) is called the arm projection.
Commercial retractable patio awnings have arm projections that range from 1.5meters(m) to 4m. Also, 2 folding arms can hold a fabric whose span does not exceed 23 feet as each arm is limited on how much weight and fabric bulk it can hold.
Based on the height of where the mounting bracket has been installed on the wall, simple geometric calculation allows one to calculate the height of the front (valance) bar from the patio ground when the awning has been fully projected (i.e fully unrolled on straight horizontal arms).
Evidently, the substructure is made up of the wall bracket, bars, roller tube, and retractable arms.
Angling the extension arms allows for the awning to be angled against the façade when fully projected, and this allows for angles that allow the awning to withstand strong winds to be set.
Some substructures allow for vertical supports to be installed to create a canopy.
This describes the device and mechanism used to rotate the roller tube. There are 2 types:
These are operated by hand, usually via a hand-crank. This means that when the hand-crank is rotated, the roller tube causes the cover to be projected or retracted. It is cheap and can be easily adapted to any patio.
It is called motorized because an electric motor is used to drive the roller tube, hence causing shade projection or retraction. This motor is usually concealed inside the headbox/cassette.
In a motorized awning, the extension arms cannot be used with vertical supports, hence this awning creates an unobstructed shaded space.
These arms allow the awning to be opened or closed after turning the switch ON or OFF. The switch can be a wall-mounted switch or a wireless remote control switch.
There are 2 key motor operations: switching ON and OFF the motor and regulating the motor speed.
Advanced motor models feature a built-in receiver that runs these motor operations, and because this built-in receiver takes instructions from a remote control, home automation system, or an application in a tablet, smartphone or computer; then these motor operations can be controlled by a remote device (such as the remote control or smartphone).
Lack of vertical support and the use of long arms make a motorized model prone to damage by strong winds. For this reason, some are fitted with wind (speed) sensors that allow for automatic retraction if wind speed exceeds a certain limit, usually 30mph or 48kph.
The electric patio awning can receive its power from the mains power supply, but if one desires to separate its power supply from the mains, then one needs to install a fused spur in the circuit that powers the awning.
Patio awnings can be rated based on their tolerance to specific ranges of wind speeds, and this tolerance is determined by the number of extension arms, size of the canvas (its length and width), and material of canvas. This tolerance is usually matched with the Beaufort wind force scale.
Usually, an aluminum awning, i.e, an awning that has an aluminum understructure and sometimes covered by aluminum sheets, provides excellent wind tolerance, good shade, and minimizes solar heat gain, as well as offers excellent protection against the fading effects of UV energy.
Moreover, they have a long lifespan that can exceed 50 years of continuous use. Additionally, the aluminum awning can be folded down to shield the window or door during storms and hurricanes.
High-end models use rollable solar panels as covers, or their covers are impregnated with photovoltaic cells so that they can generate electricity when rolled out during a sunny day.