diy shade ebook

DIY Shade Shadesails Made Easy

2012 www.diyshade.com.au Page 2

TABLE OF CONTENTS About the Author ....................................................................................................................................................... 4

CHAPTER 1: INTRODUCTION TO SHADESAILS .................................................................................... 5 WHY INSTALL A SHADESAIL .......................................................................................................................................... 5 What is and What is Not a Shadesail ................................................................................................................ 6 UVR Facts ...................................................................................................................................................................... 7 IN SUMMARY ..................................................................................................................................................................... 7

CHAPTER 2: PLANNING FOR A SHADESAIL ........................................................................................... 8 DO I NEED A PERMIT OR LOCAL PLANNING PERMISSION? ........................................................................................ 8 IS A SHADESAIL REALLY THE RIGHT OPTION? ............................................................................................................. 9 WHAT EQUIPMENT WILL BE REQUIRED? ................................................................................................................... 10 MOVEMENT OF THE SUN .............................................................................................................................................. 12 CHAPTER 3: SHADESAIL DESIGN ............................................................................................................ 18 HOW SHADESAILS ARE MADE ...................................................................................................................................... 18

Ready Made VS Custom Made ........................................................................................................................... 19 Types of Shadesails ................................................................................................................................................ 19 THINGS TO LOOK FOR WHEN ORDERING A SHADESAIL ........................................................................................... 20 Shape ............................................................................................................................................................................ 21 Size ................................................................................................................................................................................ 22 Shade cloth Fabric ................................................................................................................................................. 22 UVR Block VS Shade Factor ............................................................................................................................... 24 SHADESAIL DESIGNS ..................................................................................................................................................... 26 Triangular Shadesails .......................................................................................................................................... 29 OTHER DESIGN IDEAS ................................................................................................................................................... 36

CHAPTER 4: INSTALLING THE ATTACHMENT POINTS ................................................................... 37 CHAPTER 5: MEASURING UP FOR THE SHADESAIL ......................................................................... 47

How to Measure ...................................................................................................................................................... 47 TURNBUCKLE & HARDWARE SELECTION ................................................................................................................. 50 Hardware Guide ...................................................................................................................................................... 51

CHAPTER 6: FITTING THE SHADESAIL ................................................................................................. 53 Tensioning Larger Shadesails ........................................................................................................................... 54

CHAPTER 7: SHADESAIL MAINTENANCE ............................................................................................ 55 APPENDICES .................................................................................................................................................. 56 1. SYNTHESIS COMMERCIAL 95 TECHNICAL SPECIFICATION SHEET .................................................................. 56 2. SHADESAIL MEASURING GUIDES ............................................................................................................................ 57 3. RAFTER BRACKET FITTING GUIDE ........................................................................................................................ 61 CONTACTS & USEFUL LINKS ........................................................................................................................................ 62 EXAMPLE OF A LOCAL COUNCIL SHADESAIL APPROVAL & REQUIREMENTS ...................................................... 63



Disclaimer

Whilst every attempt has been made to provide accurate information it must be understood that shade sails should only be installed by suitably capable and qualified persons.

Safe working methods must be adhered to at all times. Such methods may be dictated by specific onsite circumstances which are outside the scope of this book. It is incumbent on the reader to

familiarize themself with such methods and to apply them at all times.

If you do not have the necessary experience or ability in this area it is recommended that a building professional be engaged to install your shade sail and you use the information in this book to act as a

supervisor or consultant to the project. All information in this document is provided as general guide only. Specific site considerations must

always be taken into account. It is incumbent upon the person reading this book to make all necessary safety checks and take all necessary precautions and preparations regarding their own

safety and that of others. It is recommended that for specific engineering and installation matters that suitably qualified professionals be engaged or consulted. The author of this book does not accept any liability whatsoever for the way in which this information is used or applied. Furthermore, all liability for damage, loss, injury or expense whether direct or indirect arising from the use of this

information is expressly excluded to the full extent of exclusions under Federal and state law. No warranties are extended to any works carried out by any persons using information in this book. No

promises are made as to any end result any one person may or may-not achieve from reading and/or employing any information covered in this book. It should be noted that this book must be read only upon acceptance of these stated terms. Should any person not accept these terms in their entirety they should immediately contact Shade Australia within 5 days of purchase of this book whereupon

they will be supplied with a full refund.



Do It Yourself Shade Shadesails Made Easy

by Andy McLeod

About the Author Andy McLeod founded his company Shade Australia in the summer of 2000 believing that as the hottest country on earth with the highest rate of preventable skin cancer in the world, Australia should be the leader in the provision of high quality shade for outdoor activities.

Andy has been involved in the design, manufacture and installation of thousands of shadesails and this book is a compilation of the knowledge he has gained over that time.

If you; are either planning to design and install a shadesail yourself or you want be able to

direct and manage tradespeople to do the job for you wish to save yourself some money want to understand what you should be paying want to achieve a safe, strong structure want to make sure the shade is cast where you want it

then this book has been written for you!

Shade Australia supplies shadesails to customers across Australia and around the world. The company has customers in New Zealand, Greece, Italy, Canada (yes really), United Kingdom, USA, South Africa, France and beyond.

Important Note: This edition of DIY Shade is written from a Southern Hemisphere perspective. All measurements are metric.



Chapter 1: Introduction To Shadesails

Over recent years, shadesails have become increasingly popular. In many public spaces such as schools and parks, the provision of shade is now a statutory requirement. This is understandable when it can take just 11 minutes of exposure to mild UV radiation for the skin to exhibit the first signs of sunburn. Shadesails today are sophisticated structures that are designed and engineered to look great and be safe in a variety of conditions. They are made from advanced polymers (usually polyethylene with UV inhibitors) and are designed to withstand the suns UV rays

for up to a decade. Of course, this has not always been the case and shade sails in some form have been around for thousands of years. The shadesails today are essentially an evolution of the ancient Bedouin tents. These tents were constructed using wooden columns with a canvas canopy stretched over them and held secure by guy ropes. Like this one many had sides and were used as living quarters. Shadesails today typically dont have sides, they only have the roof structure and are installed more to provide safe UV zones for short-stay outdoor activities.

Shadesails have become popular as they;

are a cost effective way to span large areas look aesthetically pleasing are a proven system for blocking UV Radiation are infinitely flexible in size, shape and design are relatively easy (once you know how) to install

Commonly referred to as tension membrane structures the types of shadesails we discuss in this book are quite sophisticated. They use the latest technology in shading materials and rely on engineer certified columns and fittings to create striking structures that not only look spectacular but also provide high levels of UV protection. In fact, it is recommended that the shades today provide a minimum level of at least 94% UV protection.

Why install a Shadesail The simple fact is, most Summer outdoor activities these days require us to protect ourselves from UV radiation (UVR). Whether its sunscreen, shade or protective clothing, the provision of some UV protective during the hotter months of the year is now mandatory. The provision of high quality shade in outdoor areas where people congregate is

Why We Love Shade

Think about it, the hotter it gets the harder it works, it runs for free, its 100% environmentally friendly and without a doubt quality shade is the safest sunscreen ever invented.



arguably the safest form of protection there is.

In fact, according to a leading specialist in this area, Architect, John Greenwood;

The provision of quality shade is the single most important way [people] can protect themselves from the increasing levels of UV radiation.

Shadesails are a cost effective way to cover large areas. The main reasons for installing a shadesail would be:

to provide protection from the sun and dangerous UV radiation to create cool outdoor areas where people can safely congregate to provide aesthetically pleasing structures to make areas look modern and inviting

Shadesails are installed in a vast range of situations. Some of the most common areas where shadesails are installed include;

Swimming pools Courtyards Cafes, Restaurants and outdoor dining areas As awnings or verandas In agricultural applications to provide shade to animals including sheep and cattle,

horses, aquaculture, horticultural Car parks

What is and What is Not a Shadesail Before we get too far along, lets define what is and what is not a shadesail. Firstly were talking about Shade Cloth Sails, were not talking about waterproof sails which are made from a different material and have different characteristics.

This is a shadesail. It has three or four (or more) outer attachment points but no internal structure. The tension is achieved by pulling outwards at the corners. Cable or webbing stitched into a perimeter hem of the sail is tightened and the fabric sail takes shape. Nothing is holding it up in the middle, only the tension exerted on it from the corners. This is why shadesails are often referred to as tension membrane structures.

This is not a shadesail. Although it has four (or more) outer posts and the canopy is made from shade fabric, the difference is that this structure has internal supports over which the fabric is suspended. This frame supports the fabric as opposed to a shadesail where there is no internal frame. What we are looking at here is a Shade Structure, (or a hip and ridge structure) not a shadesail. This is not a shadesail. This is a shade canopy. It has regularly spaced eyelets punched into its perimeter similar to a tarpaulin. It is then laced onto a supporting outer frame. Shadesails do not require an outer supporting frame.



UVR Facts The by-product of installing a shadesail is the creation of cool shaded areas which are inviting for people to use during the heat.

Looking at a typical UV index chart we can see that UV radiation is normally highest during the middle of the day, mainly between 10am and 2pm. However, on a hot Summer day we can see that there is UV radiation present at dangerous levels from before 9am through to mid or even late in the afternoon.

UV radiation is the invisible light which comes from the sun. It is directly linked as the main cause of melanoma. Even today many people are unaware of just how insidious UVR really is. They are unaware for instance that the first signs of sunburn can occur in children in as little as five minutes exposure to high UVR.

Samantha Conias of The Australian College of Dermatologists advises Studies have shown that as little as six sunburns can double the risk of melanoma.

In Summary The provision of UV Protective shade in our outdoor areas today is no longer a luxury, its a necessity. The purpose of this book is to give you the information you need to consider, to design and install a professional quality shadesail which will look great and last for years. If after reading this information you decide that the installation part of the job is beyond your abilities you will be well educated to engage a contractor and be able to give them clear instruction as to exactly what your requirements are and how the job should be done. You will be knowledgeable about the best types of shade cloth to use and how to position the shadesail itself so that it provides the coverage you need at the time of day you need it.

This book will also save you a great deal of money by using the right materials and having them installed to the correct specifications.

In fact, I dare say, by the end of this book you will know as much, if not more about installing shadesails than some of the shade industry contractors who do this for a living.



Chapter 2: Planning for a Shadesail

There are a number of important things we need to go over before we start. Lets address them one at a time.

Do I need a permit or local planning permission? The answer is you should check. My experience over the years has been that virtually every district has slightly different regulations. For instance some council areas stipulate that if you are installing any form of structure with an area greater than 10m2 you require council approval. In other areas it can be 15m2 or larger. Some councils dont class shadesails as permanent structures because they are fabric, and unlike a metal roof, can be removed. Others do because the posts are concreted into the ground and this constitutes a permanent installation.

I am not able to prove you specific advice on your local area in this book and even if I did, your local planning authority might just as easily change its regulations next month and the advice would be out of date.

Accordingly, you should contact your local authority and seek advice1. I can confirm, however, that in our experience the following general guidelines apply:

If the shadesail is to be installed in a public area such as park or pool then you will almost certainly require local planning permission.

Most people who install shadesails in their home will seek council approval if the shade sail;

a) casts shade onto a neighbouring area b) blocks or interferes with a neighbours view c) is within one metre of a neighbours boundary d) alters the streetscape e) can easily be seen by anyone

Can I do it myself? Hopefully with everything you learn here the answer is YES but of course only you can answer this question. This book gives you the information you need to make that assessment.

Even if you cant, or choose not to do the job yourself, by using the information in this book you will be informed about exactly what needs to happen and will give you a much better chance of getting the end result you want at a fair price rather than hoping you are getting good advice from tradespeople.

1 Included in the back of the book is an example Local Council Shadesail Requirements Document

which will give you an indication as to what documentation a Local Council might need you to supply.



Is a shadesail really the right option? Good Question! Shadesails have proven highly effect in many locations and applications but not all. I recommend before you push ahead with your plans to install a new shadesail that you pause for a few moments and consider their benefits and pitfalls. Ive done a short For and Against table below (warts and all) which you can go through in the context of your area and what you what to achieve. At the end of the day, we all want you to end up with best possible solution and if you decide from reading this book that a shadesail isnt right for you then your research will have been worth it.

For Against Excellent for creating cool UV protective

areas for short term activities such as swimming

Work best when the area is relatively symmetrical e.g., 6 x 7 metres.

Their dramatic architectural look can create drama and interest to the area.

Can be cost effective over large areas.

They are very low maintenance.

Flexible shapes and custom shapes can be made to fit irregular areas.

Available in a great colour range to blend into an area or to stand out and make a statement.

They can be removed during the winter months if you want to get the sun at those times.

Although high wind areas are not recommended for shadesails they are significantly more wind tolerant than many other options such as Folding Arm Awnings.

Can not be moved around like a cantilever umbrella to cast the shade where you want it as the sun moves across the sky so careful planning is required for effective protection from morning and late afternoon sun.

They are not waterproof.

They are often more expensive than first anticipated, especially when having a contractor do the entire job.

Require firm natural ground for the columns.

Not really suitable for long narrow areas eg 3 x 8 metres.

On rooftops and balconies achieving appropriate and secure attachment points can be very difficult.

A lot of coverage is lost due to the curvature of the edges

Further coverage is lost at the outer corners where the tensioning devices (e.g. turnbuckles) are fitted

They typically dont have sides leaving the area underneath open to the elements.

Typically shade cloth is a flammable material. FR (Flame Resistant) fabric is expensive and can be difficult to source.



What equipment will be required? To install a professional quality shadesail requires quite a bit of work and some basic equipment. If you do not own everything on this list do not worry most of it can easily be hired. Lets run through the basics of whats required.

Basic equipment includes:

compass (or accurate knowledge of where North is located on your property) long tape measure ladder drill string for string lines spirit level knowledge of the structure of your house

For in ground columns

Vehicle which can carry lengths of steel (such as a ute or roof racks) Wheelbarrow Shovel Auger Strong flat piece of timber approximately 30cm wide x 1.5m long Underground services plans including knowledge of location of conduits through existing

concrete slabs, Telstra cables etc

Deciding on the position of the columns

You must plan to install the columns further out than the area of the shadesail itself. This is because the corners of the shadesail do not come right up to the columns. Most shadesails require a tensioning device such as a turnbuckle at the outer corners. What this means is that you lose around 30cm of actual coverage at each corner so in order to compensate, you have to install the attachment points further apart.

Digging the holes

This is probably the hardest part. The bigger the shadesail you plan to install, the deeper the holes need to be. As a general guide, even with a small shadesail the holes will need to be 1/3 in the ground, 2/3 out ie, a least 1 metre or 33 deep. If the ground is hard you may need to hire an auger from a local hire shop to get the job done. If you are installing a large shadesail, the holes need to be deeper than this and it isnt practical to dig the holes by hand. In this instance you may need to hire a mini-digger or get a contractor in to do this part of the job for you. When we talk about the hole diameter and depth we are always assuming firm natural ground. Typically what that means soil which hasnt previously been disturbed. Backfill for instance in a garden bed will not provide a firm support for the columns and as soon as tension is applied, the columns will shift.



Installing the columns

We recommend using metal columns and they are heavy. Usually your local steel merchant can cut them to length and deliver them. They can be heavy to lift into the holes and this is the point you might need some extra manpower on hand.

Mixing and pouring the concrete

Once the steel columns are in the holes they need to be concreted in. A typical hole might be 50cm wide x 1.2 metres deep. This requires .03 of a cubic metre of concrete2 or about two to three wheelbarrows full. This is quite a bit of mixing on site but it can be done. Using a concrete mixer makes it easier or what makes it easier still is having the entire load of concrete delivered in a Mini-mix truck.

Having the concrete delivered makes a tough job easy and it also allows you to specify the strength of concrete you need rather than just guessing.3 Fitting the shadesail

This is the fun bit. It does, however, require working on ladders to reach up and hook the shadesail onto the eyebolts for tensioning. If youre not confident and experienced at working on ladders this might be something you choose to outsource.

You might decide to get in a tradesperson for some parts of the job such as digging the holes whilst doing other parts yourself such as fitting the shadesail.

How do I ensure that I will end up with a quality job? That is the purpose of this book. We cover all the information you will need and alert you to the most common mistakes people typically make when they decide they are going to design and install a shadesail by themselves. Two of the most common mistakes that people make which by reading this book you will most certainly avoid are;

1. using columns which are too light / and not making your footings big enough. Both these things are common causes of shadesails sagging, looking amateur and subsequently failing.

2. Not understanding the curvature of shadesails and thus not getting adequate shade when the job is complete.

2 We show you how to calculate the amount of concrete you will need in a later section. 3 Note: A minimum of 20mpa strength concrete is required.



Permanent or Temporary

As a general rule, a shadesail of the kind and quality we are discussing here should be considered a permanent installation. Using high quality fabrics, cables and attachments the shadesails should be able to withstand most conditions. Having said this, shadesails are not designed to withstand extreme weather events and very high winds. Although taking a shadesail down on a regular basis isnt recommended (or if the job is done correctly, not required), when forecasts predict strong weather events approaching, it would be wise to organise for your shadesail to be taken down and stored until conditions are back to normal.

Often times many people install shadesails in courtyard areas where they need protection from the heat and sun during the hotter months but in the winter they want use of the area to enjoy the milder sun. This isnt a problem as there are a number of simple ways shadesail can be installed so they are relatively easy to take down and put back up as the season requires.

Movement of the Sun The sun is constantly moving it rises in the east and sets in the west.

One very important thing you should consider when planning your new shadesail is this apparent movement and its effect on where the shade falls. My experience is that its fairly common for people to forget to take this into account when planning their shadesail and the end result is that the shade doesnt fall where they need it. A bit of forethought and planning here will mean the difference between a great result and a disappointing one.

Typically what happens is that most people fit the shadesail directly over the area (e.g. an outdoor table) they want to cover. This works well at certain times of the day but poorly at other times. Shadow planning is quite complex and other than to provide a general overview it is beyond the scope of this book, however, if you have a general understanding of the principles and follow some simple rules youll end up with a much better result.

Firstly, if you want the shade to cover a certain area in the middle of the day then fit the sail more-or-less directly over the area you want to shade. If you want the shade in the afternoon then you need to install the shadesail more toward the setting sun. What happens then is as the sun begins to get lower in the sky, it casts the shade back to the area you need it. Likewise, if the most important time you need the shade is in the morning then install the shadesail more toward the direction of the rising sun.

Lets review the following three shadow diagrams to get a better understanding of this.



Diagram 1 below shows a shadesail installed over an outdoor seating area. This example shows the shadow pattern on a typical mid-morning (as viewed from the north). As you can see, the shade is casting well out to the side, away from the sun. If it was important in this situation that the seating area be completely shaded in the mid-morning period, then the shadesail should have been installed more toward the east or morning sun.

Diagram 2 shows the same shadesail on a typical mid summers day. Quite clearly the shade is right over the seating area. If a well shaded area was required for an early lunchtime, this would be perfect.

Diagram 3 shows the opposite of diagram 1. The shade is casting out to the eastern side away from the setting sun (as viewed from the north). If the shade for this area was needed for mid-afternoon activities then this would be a poor design. Instead the shadesail should have been installed further to the west such that in the afternoon the shade would cast back to where it was required.



The diagram below4 shows the difference in the Altitude of the sun between summer and winter. It references the angles of the mid-day sun for Melbourne Australia and contrasts the altitude of the winter sun which reaches only 28.5 on the winter solstice (i.e. the shortest day of the year, 21st June) with the altitude of the sun on the summer solstice (i.e. the longest day of the year 22nd December) as it reaches 75.5 above the horizon.

This of course has a dramatic impact on where the shade falls at different times of the day and at different dates in the year.

From a DIY Shade Installers perspective, its important that when youre planning your shade project that youre aware of the following:

The direction of True North.

In summer in the middle of the day the shadows will be short and the shade will fall close beneath the object casting it. (Remember: High Sun = Short Shadows which cast close in beneath the shadesail.)

In the morning and afternoon the sun is relatively low in the sky and it will cut in under the shadesail causing the shade to cast out to the opposite side. (Remember: Low Sun = Long Shadows that do not fall directly beneath the shadesail)

In winter, the sun never gets very high in the sky therefore the shade never really falls directly beneath the shadesail. Typically winter isnt as important for shade planning because the suns intensity and the resultant UVR are not as great.

If youre not sure about all this theory on sun angles and shade projections and wish to take a more practical approach then I can make two recommendations.

1. Take some time to do a little bit of your own shadow modelling. Watch where the sun comes up and where the shadows are cast during the day and take notes or mark the ground with chalk. I once visited a customer who was doing his own scale-model of where the shade would fall at certain times of the day using a table. Hed carried a table out to the area that he was planning to shade and over a period of time he watched and recorded where the shade fell at certain times of the day.

4 http://museumvictoria.com.au/discoverycentre/infosheets/planets/the-sun-and-the-seasons/



After a while he had a pretty good idea of where he needed to build his shadesail to get the best shade for his purposes, he was able to scale-up his model into an actual shadesail, confident that the shade would fall exactly where he needed it at the appropriate times of day.

2. If you are really serious about getting it exactly right then you might want to have detailed shadow projections done for you. This isnt as hard or expensive as it sounds. All you need is a plan of your area with a sketch of the shadesail where youre planning to install it. Indicate on the plan the heights of the posts and where north is and the rest can be done for you. Ive included the contact details at the back of companies we have used to do this for various clients.

Having some Visual Representation Plans (VR Plans) prepared can also be a useful tool in getting a clearer idea of what the final job is going to look like. We do this a lot for bigger jobs or if were exploring various concepts and wanting to give the client some options. Its not overly expensive and can be a really useful tool to use yourself if youre not sure how the final job will look. Of course VR Plans are also useful to accompany plans to council or when youre part of a committee and you want to make sure everything turns out exactly as planned.

The CAD (Computer Aided Design) Diagram below was prepared from a hand-sketch we sent to the Shade Modeller. They provided us with these visuals which we sent to the client. The client was able to get a clearer idea of exactly what they were going to end up with. As you can see from the subsequent photos, the CAD diagrams were a pretty accurate representation of the final job and everyone was happy.



The actual shadesail we installed as represented by the VR Plans we had done.

The client was delighted with this installation as it was exactly what they had expected.



Useful Definitions and Dates

Azimuth: Refers to the angle of the sun measured clockwise from north. Think of it like this, if you point the 12 on a wristwatch toward the north then if the sun was directly behind you it would be at an azimuth of 180.

Altitude: Refers here to the height or angle of the sun above the horizon. For example in Melbourne Australia, the highest the sun gets in the sky is an altitude angle of 75.5. If you were standing on the equator at the exact same time, the sun would be directly overhead or have an altitude of 90.

Zenith: Refers here to the highest point of the sun on a given day.

Solstice: Refers to two occasions of the year known as the summer and winter solstice. In the southern hemisphere the winter solstice is the shortest day of the year and the summer solstice is the longest. The winter solstice in the Southern Hemisphere occurs about June 21 whilst the summer solstice occurs about December 22. The summer solstice is around June 21 in the Northern Hemisphere with the winter solstice occurring around December 22.



Chapter 3: Shadesail Design

How Shadesails are made When designing a shadesail it is useful for you to understand the basic principles used in manufacture.

A shadesail is a large piece of fabric manufactured in such a way as to allow it to be tensioned up between columns or other attachment points. In order that a shadesail fits tightly and does not flap, the edges of the shadesail are curved. The technical term for this is the cutinary edge (meaning: cut-in-edge). It is also referred to as scalloping or just curvature. Along this curve, a hem is sewn and into that a strong webbing or steel cable is fitted. On each corner of the shadesail a strong ring is fitted.

When tension is applied from the corners, this internal cable is pulled tight. As it gets tighter it tries to straighten thus pulling against the edge of the fabric and causing the belly of the shadesail to also become tight.

Many people ask why shadesails have curved edges and this is the reason. If the shadesail was just a square piece of fabric with no cutinary edge there would be no way to apply even tension across the entire surface of the fabric. This would lead to;

1. the belly or centre of the shadesail sagging 2. the overall shadesail not being tight 3. The sail flapping in the wind

If a shadesail isnt tight, it will flap and in a short period of time will rip out the stitching and flap itself apart.

Typically a shadesail is made with a cutinary edge of between 5-8%.

Cutinary edges on shadesails are necessary. Yes, you do lose overall coverage but without the curved edge the sail will not tension up correctly.

On this example, if the length of the shadesail was 6 metres and the cutinary was 5%, the scallop or curvature at the deepest point would be 30cm.

Formula: 6000mm x 5% = 300mm

When I first started in the industry, most shadesails were laid out on the floor and cut with shears. Today, modern technology allows the whole thing to be done on a plotter-cutter. The fabric isnt touched by human hands.

Curved Edge of a Shadesail With a 5% cutinary

Nominal straight edge 6 metres



The corner of the shadesail will not start directly at the attachment point as there must be a Tensioning Allowance. This is because shadesails need a tensioning device which links them to the attachment point (e.g. the eyebolt on the post). The most common way to achieve this is to use a turnbuckle and we will talk more about this further on. The Tensioning Allowance is mentioned here to bring it to your attention at the design phase of the project.

There are occasions when shadesails can be attached directly to the eyebolt in one or more corners. My preference is to avoid this as much as possible. The reason is that it does not allow any room for error. Shadesails are fabric structures and although the manufacturing of them today is quite accurate, they still vary from time to time in terms of the amount of stretch etc. If the shadesail is slightly too big then there is no room for adjustment leaving no way to take up the slack. I recommend, particularly as a DIYer that you include a turnbuckle at each corner.

Ready Made VS Custom Made Ready-made shadesails seldom give a professional end result. The reason is that it is nearly impossible to purchase a standard size sail and fit it perfectly into an existing space. Ive seen it dozens of times where people purchase a standard size shadesail, say 5 metres x 5 metres square. They then go and put their posts in at spacings of 5 metres apart. What theyve forgotten is to allow adequate room for tensioning. What they end up with is a sagging and very amateur looking shadesail.

Also common is when people install a standard sized shadesail but for some reason they cant install one of the attachment points in exactly the correct position. What happens then is that the sails pulls crookedly causing bunching and wrinkling at one or more corners.

I will emphasise here that as with most things you really do get what you pay for when it comes to shadesails. Standard sized, ready made shadesails purchased from a hardware store are all imported. Most are maximum 90% UV. The difference in quality between these hardware store sails and an Australian made product is exponential.

Types of Shadesails Essentially there are three main methods that are used to make shadesails and they have to do with how the perimeter of the sail is made.

1. Webbing Perimeter: Typically a webbing perimeter (similar to seatbelt material) is used for smaller shadesails. It can be sewn either into the hem or directly onto the edge of the fabric to act as the hem itself. Webbing shadesails work well in situations where the shadesail is intended to be put up and taken down on a regular basis. The shadesails dont require as much tension to get them tight, they are lighter in weight and the webbing is easy to fold into a bag or box.

IMPORTANT NOTE

The best (and correct) way to ensure the shadesail fits perfectly is to install the

attachment points first and then take the measurements, not the

other way around.



2. Continuous Cable: This is where a hem is sewn around the entire perimeter of the shadesail and then a cable is threaded all the way through. At one corner both ends of the cable overlap. Here there are two wire-rope grips. As the shadesail is tensioned, the cable slides around and finds its own natural position. Before any amount of tension is applied, the wire-rope grips are locked off and the tension is then transferred onto the perimeter cable. This is a very good system and is widely used. The downside is that for the DIY installer, it adds another level of difficulty, recognising the right moment to lock off the wire-rope grips.

3. Pre-Swagged Shadesails: Swaging simply means pressing a metal clamp to form a loop at the end of a cable. Before shadesails were patterned by computer, it was almost impossible to pre-swage or lock off each corner of the internal cable because it was hard to match the stretch of the fabric to the length of the cable. Today, with modern technology this is possible and in fact is how my company makes almost all of our shadesails. The cable running around the perimeter is locked off at each corner. The great benefit of this apart from its inherent strength is the ease of installation particularly for the DIY installer.

Things to look for when ordering a shadesail There are a few key factors you should be across when considering who to order your new shadesail from. These include:

1. The Fabric: What type of fabric is the shadesail made from. Later on Ive listed some of the more widely used fabrics. Essentially you need to be using a fabric which is designed for a tension application. Certain fabrics are made specifically for shadesails, however, many are not.

2. The Stitching: Consider what type of stitching is used. The stitching is one of the most common areas that a shadesail fails. We frequently get people bringing in cheap quality shadesails to ask if we can restitch the perimeter. When commissioning your new shadesail you should consider if the manufacturer is using a PTFE5 quality thread such as Tenara. Although using this high strength, long life type of stitching adds considerably to the overall price, it is almost certainly worth it. You dont want to be taking your shadesail down and back to the factory for restitching after just a few years. Personally Id insist on the sail being made with a UV stabilised thread.

5 Polytetrafluoroethylene



3. The Corners: If you know what youre looking for you can really tell if youre getting a high quality shadesail or not. The corners are a very important part of the sail itself as they take the majority of the load. The perimeter cables or webbing will come to some sort of ring at the corner. This ring should be heavy duty and should be stainless steel. Supporting the ring there should be a webbing strap which is sewn back into the fabric. This keeps the ring straight as well as giving additional support. One thing weve done with all our shadesails is to build in what we call Cyclonic Corners. This type of corner has an additional layer of fabric sewn into the corner (called Doublers) with extra stitching to stiffen the corner up and make it really strong. If the stitching is inadequate or the corner isnt reinforced, youre almost

certainly going to get a failure in strong winds.

Pre-Swaged Corner

This photo shows the stainless steel wire in the hem and the mechanical swage. The swage is pressed onto the wire cable and locked place. Pre-swaged shadesails are very strong and very easy for the DIYer to fit. Before shadesails were plotted on computers it wasnt possible to cut the wire and lock it off in exactly the correct position.

Shadesail Corner

The corner is the place where everything comes together in a shadesail and where you are able to really assess the workmanship of a good quality sail. Look for:

A heavy-duty stainless steel ring Webbing which has been doubled holding the ring to

the sail Additional stitching at the corner to make it strong. Two lines of stitching around the hem of the sail A heavy-duty stainless steel wire rope sewn into the

hem Overall neat workmanship

Here are some other important features you should look for when ordering a new shadesail.

Shape Shadesails work best when they are a relatively symmetrical shape. For example a six metre by seven metre sail is relatively symmetrical and works really well whereas one which is say seven metres x three metres is asymmetrical and doesnt work so well. The reason for this is the curved edges.

TAKE NOTE

The rule of thumb is a

shadesail should be at least half as wide as it is

long.



In a symmetrical sail the curvature of the sail is minimized across its entire shape. On a sail which is long and narrow, the curved edges on the long side are greatly accentuated and the end result is a long sail with a narrow centre.

One way to overcome this is to add additional attachment points. If for instance the area you wished to cover was seven metres by three metres you could add an additional attachment point mid-way along the seven metre side to minimise the curvature. This would result in two smaller scallops rather than one deep one.

The downside of this is that it makes manufacture and installation more complicated. If you look at the measuring guide in the appendices for a six point sail you will see that you need to take a set of 15 individual measurements (instead of six for a standard four point sail). If even one of these measurements is wrong the sail cant be made and you will need to go through the time-consuming process of remeasuring. Also, adding additional attachment points adds extra cost to the sail due to the additional processes involved in manufacture.

Size As a DIY shadesail installer we would recommend that you dont tackle a shadesail any bigger than 10 x 10 metres. The main reasons for this are:

1. Firstly, because the bigger the shadesail the deeper the holes, the heavier the columns and the harder it will be to tension the shadesail.

2. Big shadesails can be quite difficult to fit. Often times a small block and tackle is required to get them tight and most DIYers dont usually have this kind of equipment.

Shade cloth Fabric Shadesails, also known as shade cloth sails are made from an advanced polymer material called Polyethylene. The type of fabric which is suitable for tensioning applications is a knitted (not woven) construction. Thin strands called monofilaments, a bit like fishing line, are knitted together on large machines to create a very strong mesh. Depending on the brand and application, sometimes a flat tape is knitted into the fabric which is designed to increase the shade factor of the cloth whilst minimising the GSM (grams per square metre) or weight of the fabric. Each strand of the fabric is treated with UV stabilizing agents so that the material is impervious to the harsh UV rays it will be exposed to.

Over the last decade great advances have been made with the pigmentation of the material so that it remains colour fast for its entire lifespan. Not so long ago if you installed a black shadesail within just a few years it you would look up to see that it was now a motely shade of elephant grey. With most of the leading fabrics today, this wont happen. If you buy a black shadesail, after a decade, it will still be black. Some fabrics are further treated with fire retardant agents.

Below is a summary of some of the most widely used brands of commercial shadecloth suitable for shadesails and when you are looking to install your own shadesail the brand you choose should be well proven in the market place.

Long shadesail with mid-attachment point



Youll notice that most shade cloth fabrics today extend a 10 Year Pro-Rata warranty. This simply means that if after nine years the fabric fails and you make a warranty claim, the manufacturer will make an assessment and if deemed a legitimate warranty claim will credit you back one years value only.

Brand UV Degradation

Warranty

General Comments

Synthesis 10 yr. Pro rata

Gale Pacific manufactures the Synthesis Range of shadecloth. The Synthesis Shadecloth Range utilises the latest technologies to combine High Density Polyethylene, advanced Ultra Violet (UV) stabilisers and pigments and the latest manufacturing techniques to produce a broad range of shadecloth for a number of applications. Included in the range are: Synthesis AF-230 A lighter weight shadecloth for smaller projects Commercial 95: A heavy duty, high shade factor fabric that continues to perform in the hot Australian sun. It features high shade factors of 95% (depending on colour) making it widely suitable to applications such as playground shade. AF-350: Gale Pacifics extra heavy duty shadecloth built for large shade applications http://www.synthesisfabrics.com

Monotec 10 year UV Warranty

Australian made, the Monotec 370 series is a very high strength shade cloth. Stiff and heavy to touch with little stretch this fabric offers an extensive range of colours including many very bright colours such as lime, orange etc. It ranges in shade factors from 50% to a maximum of 90%. http://www.monotec.com.au

Rainbow Z16

10 Year Pro rata

A widely used fabric that has proven itself over decades of use. Extensive range of colours. Best suited to small to medium shadesails as it can stretch in some high wind or larger applications. It has been rated up to 99% UV block http://www.rainbowshade.com.au

Coolaroo Usually 5 Year Pro rata

This is Gale Pacifics retail or domestic shadecloth brand. It is primarily used for shadecloth blinds, pergola covers etc. Smaller ready made (imported) shadesails are available in the material. The UV rating is usually a maximum 90% in a limited colour range. http://www.coolaroo.com

PolyFab 10 Year Pro rata

Polyfab supplies a range of high quality shadecloths including: Architec 400: An extremely strong product made for very large shadesail jobs Comshade: A heavy duty knitted shadecloth designed for commercial and heavy duty shade applications FR Comshade: A shadecloth with fire retardant properties PolyFX: A knitted shadecloth suited to smaller shadesail applications such as covering pools and courtyards. http://www.polyfab.com.au



UVR Block VS Shade Factor Shade cloth is rated by both its UVR Block and its Shade Factor and these terms can be confusing.

Shade factor refers to the amount of shade being cast. For instance a solid brick wall would cast a 100% shade factor (a shadow) where as say a vine over a trellis might only cast a 50% shade factor. You can roughly gauge the shade factor by looking at the shade/shadow on the ground. If you stood in the shadow of a brick wall, your shadow would be invisible as it would blend into the complete shadow of the wall.

In the picture below, photo A shows a person standing in complete sunlight and their shadow is crisp and clear. In photo B they are standing under a shadesail. Their shadow is now obscured by the shadecloth. The shade factor of the cloth is high (maybe 90%) but not absolute. In photo C they are standing almost in complete shade their shadow is barely visible. The shade factor in Photo C would be the highest.

A high Shade Factor is important when selecting which shadecloth to use for a shadesail. A material with a high shade factor creates a cool and welcoming shade area. Shade factor, however, doesnt directly relate to Ultraviolet Radiation Block or UVR Block.

UVR Block is a measure of how much potentially harmful radiation is reduced, or blocked by a fabric or cloth. UVR block is an important measurement to understand when it comes to shade cloth because it is UV radiation which leads to sunburn, skin damage and increases the risk of developing skin cancer. A UVR rating of 94% is the recommended minimum UVR block you should be looking for when choosing the brand of shadecloth for your shadesail.

The table below shows the technical data of Synthesis Commercial 95 Shadecloth. This is one of the main reasons why my business has continued using it for all these years. Look at the column to the far right and you can see that the tested % of UVR Block for most colours is very high. Most of the colours test above the 94% level meaning that in test conditions this was the percentage of Ultra Violet Radiation (in the 290nm 400nm spectrum range) which was absorbed or blocked by the shadecloth.



Shadesail Colours

Shadesails today come in virtually every popular colour. Different manufacturers have different colour ranges so if you are after a specific colour you can advise your shadesail manufacturer or do some research online yourself by visiting some of the fabric manufacturers websites. This chart shows a selection of the common colours available in Rainbow Z16.

Ive found over the years that very light colours including White, Champagne, Natural can produce glare, especially over pale coloured paved areas or around swimming pools. Also, some of the Champagne / Natural colours can look more yellow than anticipated.

Without a doubt, the most popular colour is Desert Sand. It is a neutral colour which blends in with most surroundings. It has a high UV rating and doesnt show the dirt like some colours. Most of the colours are fade-proof although I have noticed over the years that Red can fade more than any other colour.



Shadesail Designs The Hypar Design

The most widely used design for shadesails is to have diagonally opposite high and low posts. This creates a 3-D twist in the sail or what is commonly known as a hypar6. On the example sail here you can see how this is achieved. Posts A and C are the high posts whilst Posts B and D are the low. This diagonally opposite installation method is the simple yet effective way that shadesails achieve such an interesting architectural effect.

This twist creates a kind of 3-D effect and apart from the obviously striking visual appeal, it achieves several other important outcomes.

1. It allows the sail to be more evenly tensioned 2. It disperses water in heavy downpours 3. It allows the low points to be positioned toward the

direction of the sun and thus cast the shade back into the area it is required at the time it is most needed.

When planning to install a hypar sail there are a number of steps to follow to achieve a great result.

The place to start is to decide the height above ground of the low columns. This can vary greatly depending on what you are covering but as a general rule, the low posts should be set as low as practical. This goes to creating maximum shade efficiency. The lower the posts, the less sunlight is allowed to get in and the better coverage you will achieve. It is usually not recommended to set the posts any lower than 2.1 metres. In some council areas this is a necessary regulation but in practical terms, 2.2 metres is a

good height for the low posts of a shadesail. It caters well for even very tall people whilst not seeming to be too low when you are under it.

The next step is to decide in which configuration you are going to orient the sail. If it is important to you to have shade in the mornings then set one of the low points toward the east7. That way you minimize the morning sun cutting under the edge of the sail.

Next we need to determine the heights of the high posts. There is quite a simple formula for doing this.

6 Hyper is short for Hyperbolic Parabola which is essentially a twisted effect

7 southern hemisphere

TAKE NOTE

A flat sail is a poor design. It will be hard to tension,

look unprofessional, collect debris and in a hail storm may collect a large

quantity of hail putting pressure on attachment points. Always design your shadesail with at

least one point higher than the rest.



Calculating the Hypar

Take the length of the longest side of the shadesail and multiply it by 15%.

For example, if you are installing a shadesail and the longest side is 7 metres:

7000mm x 15% = 1050mm

You now just add the answer to the height of your low post. 2200mm + 1050mm = 3250mm

You now know that if you set your low posts at 2.2 metres high you should set your high posts at 3.25 metres high.

This formula is geared to achieve a striking but not overly dramatic hypar effect. It is perfect for use in most domestic situations as it balances shade efficiency with aesthetic effect. If you want to achieve a more dramatic effect they you can increase the variance in height from 15% to say 20%. Using the same size sail as above is would be the difference:

7000 x 20% = 1400

2.2m +1.4m = 3.6m

The following example photos contrast this effect and give you a good idea of how the finished sails differ.

This sail give a good example of a gentle hypar with roughly a 15% variance in height between the high and low posts. It still achieves the 3-D twisted effect without the high posts being to high and letting to much sun in.

This is a photo of a shadesail with a more dramatic hypar. The high and low posts are considerably different in height. The design brief from the director of this childcare facility was to install something that was very visually striking.

Gentle Hypar

Dramatic Hypar



Other Designs

High Point Sails

Another common design which works well is the High Point Sail. This works by installing one tall column (or attachment point) and three low points. There are several benefits to this:

1. The sail is very shade efficient as it minimises the areas where the sun can cut under the edge of the sail

2. It still maintains an interesting visual effect 3. The high point directs a run-off of heavy rain or even hail which will minimise the

likelihood of water pooling in the middle and causing the sail to sag which can lead to structural failure (i.e. the attachment points failing, the sail ripping or the posts bending)

High Point Sail

Awning or Skillion Design

As opposed to a hypar design where the high and low posts are diagonally opposite each other, an Awning design is simply where the high posts are set together at one end and the low posts at the other end. The example below show a shadesail with two high points attached back to the building stretching out to two lower columns in the driveway.

Skillion or Awning Design



This design still achieves the necessary fall across the length of the shadesail. Many people would consider this not as visually striking as a Hypar design but in some situations such as the one shown, it is simply the most practical.

Triangular Shadesails This is it - the biggest, or at least in our experience, the most common mistake people

make when installing a shadesail for the first time. They think they should install a triangular or multiple triangular shadesails that cross-over. Read on and see why this

is a recipe for disappointment.

If this book could achieve only one thing it would be to dissuade you from installing a triangular shadesail. The fact is, triangular shadesails dont work. When I say that they dont work, I mean that in the context of providing adequate shade. If you are looking for a purely visual effect then you might want to consider installing one but if your goal is to create a quality shade area for a pool or outdoor entertaining area, I strongly recommend that you do not install a triangular shadesail. I will tell you why.

As weve discussed, shadesails are made with curved or cutinary edges. This is necessary to ensure they tension up correctly. Naturally, triangular shadesails are also made with curved edges. This curvature cuts deeply into the shade area of the triangle. The loss of shade area is particularly bad in shadesails which have sides of markedly different lengths. What tends to happen is you are left with a long narrow strip of fabric which provides virtually no usable shade. In the industry this is often referred to as the G-String effect. The examples below clearly demonstrate this point.

The first example is of a shadesail that I personally installed but did not design. The posts were installed by a builder who thought he knew everything there was to know about shadesails. He sent me the measurements and although I mentioned to him that he wasnt going to get a great result, he persisted with his design. His objective here was to provide shade to this outdoor table which you can see here. After Id fitted the sail for him (and while he was having a lie down having made such a big mistake) I climbed up on his roof and took this photo. It is a good example of a very bad example of shadesail design and one I am doing my best to help you avoid.

Many people plan is to install two triangular shadesails instead of a single rectangular sail as they just like the look of the triangles. The truth is they dont know what disaster they are actually planning. The photo below shows an installation where four columns have been installed and rather than installing a normal hypar sail which would have done a really nice job, the person has chosen to get a bit clever and install two triangular shadesails to give a more interesting effect. Not only are two triangles significantly more expensive than one rectangle, notice the big gap between the two sails where the sun will stream straight through. Notice also the long narrow strips of fabric as the sails taper toward the point creating almost zero shade.



Below is another example where the designer needed to cover a large outdoor space with shade and instead of installing a series of hypar sails, he chose to install a series of large triangles. The glaring issue I see here is of course the large gaps between the sails created by the cutinary edges.



Reasons not to install a triangle shadesail:

You will get minimal shade coverage especially if the sides are of different lengths (i.e., a long narrow triangle)

Triangular shadesails are relatively expensive. For a minor incremental increase in cost you achieve significantly greater shade with a rectangular shape.

They require considerable more tension to get them tight

Another thing Ive noticed over the years is that when people see shadesails similar to the beautiful courtyard hypar sail in this photo, the actually think that it is two triangles when in fact it is simply a single hypar sail.

I think you can clearly see that this shadesail has many advantages over two triangle shadesails. Let me restate them:

It is less expensive than two triangular sails

It requires less tension on the attachment points to get it installed tight

It gives a lot more shade coverage than two triangular shadesail would It doesnt allow light to come into the central area where the shade is needed most It still achieves the architectural hypar look which so many people desire

This sail below was originally going to be a triangle. The owners of this home had small children and they wanted to provide shade in the courtyard where the children spent quite a bit of time playing. After quite a bit of convincing we agreed to add a 4th attachment point. Even though the sail is quite narrow at the end nearest the white door, you can see how much better value they achieved by putting in this extra attachment point. I know, and by now I think you do as well, that if they had in fact gone with their original idea

of a triangle, they would have been bitterly disappointed.

As a final comment on triangular shadesails I would say that they are acceptable if the triangle is equilateral - that is all sides are the same length. In this instance the cutinary is minimised and a portion of usable coverage is maintained.



Other Shadesail Designs

So far weve talked about standard four point shadesails. These are the best and easiest for DIY shade sail installers to start with because if you follow the clear guidelines given here you are going to end up with a great result. Many people, however, want to get a bit more technical or their site may require some of the more advanced options available with shadesails. Here we will cover some of those techniques.

Sail-track Edges

Sail-track is commonly used on smaller sails where a straight edge along a wall is required. The sail-track is fitted onto the wall creating a long straight groove. When the shadesail is made a rope or Kedar edge is stitched into one hem of the sail. This allows it to slide into the sail-track and create a straight side.

Sail-track edge sails can serve a useful function in some situations as they do away with one of the curved edges of the sail. Generally they arent suited to sails that have an extension (i.e. extend out from the wall) much greater than 4-5 metres as the track isnt strong enough to hold the sail in place. Sails with sail-track edges also require greater tensioning than sails without as they are lacking one cutinary edge and thus the other three edges have to take up the slack. Not all walls are suited to having this extra tension applied to them.

Five Point Sails

In instances where the sail is going to be quite long and narrow, say seven metres long by only three metres wide, additional attachment points (over the standard four corners) are a good way to minimise the curvature of the sail. In this example we added an additional attachment point to the side along the house. This helped spread the load on the wall as well as minimise the curvature along that side giving greater coverage. What works best is to make the middle attachment point some half a metre higher than the outer attachments. This helps with tensioning and also improves to the visual effect of the sail.

Six Point Sails

Six point sails can also work really well and are an effective shadesail design. They work best where the area to cover is relatively long and narrow. installing them as hypar design such as in this photo works well where the posts are alternatively high and low along the length of the sail. Alternatively, making the central posts the two high columns also works well with the lower columns on the outer edges. What I like to do with 6 point sails is to make the two central posts direct attach, that is, I dont use a turnbuckle at these two points but rather just two extended shackles. When fitting the sail I recommend first fitting the two central points and then tensioning out to the edges afterwards.



Sails with More than Six Points

Sometimes, the best way to get the job done is to install a shadesail with even more than six points of attachment. Right is an illustration of an eight point sail I put into a Dog Boarding Kennel. Due to the design of the dog-runs the owner wanted to cover all of them with a single sail. The sail itself ended up being 6 metres wide by 24 metres long. It was particularly tricky to install (due to barbed wire fences between each of the dog runs) but in the end it came up beautifully. I did it as a single sail in order to give the most coverage possible to the area.

The sail was done as a multiple hypar, that is high and low points opposite each other all way along. The benefit of doing a sail like this is to best maximum coverage. The downside is a very detailed process to actually measure-up for the shadesail. I would strongly recommend against this kind of design for a first time installation.

Double or Cross-Over Shadesails

Lots of people I speak with love the look of cross-over or one shadesail on top of another. Granted this can look great, especially if the colours of the sails are contrasted. If youre planning to do something along these lines you need to be aware that there is some additional planning required.

Playground Shadesails

I make a point here of discussing some very poorly designed playground shadesails I have seen over the years and make particular note of a commonly used design which simply doesnt deliver.

Playground sails are by their nature designed to achieve two main objectives;

1. Provide quality shade to the children (and adults) using the area

2. Look spectacular and create a visually inviting play space.

My observation is that most people involved in the planning process often forget about point 1 and focus on point 2. It is my contention that this is a mistake. Function must take precedence over form in this situation. The objective is to protect young sensitive skins from harsh UV radiation and the use of style over substance lets the entire shade industry down.



The design I refer to which is particularly guilty of achieving pretty over practical is this; where a tall post is installed in the centre with a ring of lower outer posts set around it. The central post acts as the attachment for multiple triangles which are tensioned out to the lower posts set around it.

The photo above is an example of what Im talking about. Here we have an elaborate childrens playground area which has had some very ineffectual (and very expensive) shade sails installed. Observe the massive gaps between the shadesails where the light can enter. Walking up close to the central column where the triangle sails come to their narrowest point there is virtually no usable shade what-so-ever. Granted this is a visually striking design but as far as providing useable shade are for children to safely play under on hot days, it is all but useless.

Side-shades

So far weve discussed shadesails as being overhead but this does not necessarily need to be the case. Vertical or side shades can work perfectly well and look great as well. Sometimes, a side or vertical shade is a better solution than an overhead shade. This design is particularly useful where you need to block the morning or afternoon sun and where a horizontal or overhead shade just isnt going to get the job done. The principles of designing and installing side shades are more or less the same as those of overhead shadesails. The main caveat I would offer here is to

ensure everything is made very strong, particularly the footings or foundations. This is of course because side shades catch a lot more wind than overhead shades, essentially acting in a not dissimilar fashion as a sail on a yacht. If a small sail and a light breeze can pull a boat along then certainly there is a great deal of force exerted across the sheet and strength is imperative. This sails has a column on one side and on the other it is anchored back to a building. Personally I would not be to comfortable anchoring a sail of this design to a building without independent engineer

certification. It is difficult to gauge the suitability and strength of an existing building or structure, however, you can easily identify the strength and capacity of steel posts concreted into the ground.8

8 Although I dont have any specific engineering for this type of sail, my rule of thumb is always make them

freestanding (i.e. columns in holes as opposed to attaching to existing structures such as walls) and when referencing the size of the posts and the footings, always beef them up by going to the engineering specification above what is recommended for a an overhead shadesail.



Waterproof Shadesails

Waterproof shadesails are difficult and present many traps for DIYers. The bottom-line is if youve never installed a shadesail before, then a waterproof shadesail is not the place to start. Lets address some of the reasons why:

Unlike shadesails, waterproof shadesails are made from a solid type of fabric, usually a PVC material. PVC is much heavier than shadecloth therefore it requires considerably greater tensioning.

PVC is a solid fabric with no give or stretch therefore to get a vinyl sail measured and installed without any wrinkles requires much greater skill than shade cloth.

The most common mistake with waterproof shadesails is not allowing adequate fall across the surface of the sail. I recommended a 15% variance in height for a shade cloth shadesail as an effective standard. With a waterproof shadesail, this would be the minimum you would need. The reason of course is that without adequate fall, water will quickly pool in the middle or around the lip turning it from a sail into a sump. This loads up the attachment points causing dangerous and dramatic failures of columns, walls or any other fixture. Also, once stretched PVC fabric remains stretched and will not go back to the original shape like shadecloth.

Waterproof shadesails, unlike shadecloth sails do not allow wind to pass through and therefore even a slight breeze is transferred into a strong force against the sail.

That means that the attachment points must be much more strongly engineered that for a normal shadecloth sail.

As mentioned earlier, PVC is a much heavier material than shadecloth and therefore requires greater tension. This is achieved in several ways

o Stronger attachment points o Stronger tensioning equipment (chains, turnbuckles etc.) o A requirement for a greater cutinary edge. Unlike with shadecloth sail, the

cutinary can be as little as 4-5%, with a PVC sail this should be increased to at least double that. This results in (surprisingly) less overall coverage

o Waterproof shadesails are much more expensive overall. Ive quoted out jobs where the cost of installing a PVC sail was double that of a shadecloth sail.

In summary, this book does not cover waterproof shadesail as they are a specialised type of work. My experience is that if you really want the area to be waterproof and you really want it to be a shadesail then you should contact a very experienced company in your area and get them to do the job for you.



Other Design Ideas Following are just a few more for shapes and design ideas that you might also find useful.

Different shapes and installation patterns. A series of sails in an interesting pattern

Concept plan for a double layered shadesail installation using contrasting colours.



Chapter 4: Installing the Attachment Points

The attachment points provide the structural foundation for the shadesail and as such are equally as important as the shadesail itself. More than any other factor, this is where most DIY shadesail installers come unstuck they simply under specify the strength of their attachment points and the overall job fails to live up to their expectations.

In a perfect world shadesails work best when the attachment points are poles in holes where you have full control of how deep the hole and how strong the column is. However, you may want to consider attaching at least one corner to and existing structure such as your roof, wall or fascia. Well discuss when and where to do this and when and where not to. Well also look at a selection if innovative shadesail attachment points that people have used and discuss the relative merits and drawbacks of each.

Poles in Holes

We recommend using steel columns and not timber. It is almost impossible to gauge the strength of a timber post as not all timber is created equal. Timber posts bend, bow, flex and, eventually BREAK. For any decent sized shadesail, unless youre thinking about using something the size of a telegraph column, you are going to run into trouble.

Steel posts can be measured and the strength assessed according to set specifications. Below you will see a table you can use to select the correct size column to match the size of the shadesail you are planning. Most people are greatly surprised when we tell them just how big the columns need to be and how deep the holes need to be in order to safely support the shadesail. Without this knowledge the layman takes a guess at the size of his columns and depth of his holes and invariably, underestimates and after the first strong wind the columns move and the sail sags.

What you need to know about Steel Columns

Lets quickly discuss a bit of industry jargon so that when you go to order your posts you get it right.

The timber posts bent and broke on this small shadesail after only a couple of months.

1. RHS: Rectangular Hollow Section

2. CHS: Circular Hollow Section 3. SHS: Square Hollow Section 4. NB: Nominal Bore

1. 2. 3. 4.



Definitions

SHS = Square Hollow Section

CHS = Circular Hollow Section

RHS = Round Hollow Section

OD = Outside Diameter

NB = Nominal Bore or internal diameter

Grade: 350 Grade steel is recommended as it is considered to be structural grade steel. 250 Grade steel is less expensive but it does not have the strength of 350

Column Detail

This chart shows the basic column detail. The eyebolt should be set down approx. 40mm from the top. A knock-on cap should be fitted to seal the column. Approximately 30cm from the bottom of the column, drill a hole through and fit a piece of reo-bar or galvanised 12mm dia rod. This help anchor the column into the concrete. Place a paver in the bottom of the hole to prevent the column sinking.

After pouring the concrete orientate the eyebolt toward its diagonal opposite. I also recommend tilting the column back just a fraction. That way, when the tension is on it and the top of the column flexes in slightly if youve set it back, the job will come into plumb. If you dont do this it can look like the column slants inwards which doesnt look good.

My preference is to use circular steel columns. The reason is because CHS pipe is readily available and because when installed, I think they look the most impressive. The following chart will guide you in selecting the correct size columns for the size of the sail you are intending to install. My experience is that engineers talk in OD whilst steel merchants talk in NB so its important that you know which is which and what youre getting.

Eyebolt 40mm from top

Diameter

Steel column Size as specified

Knock-on Metal Cap

Concrete Footing

Paver to stop sinking

Anti-twist Anti-lift bar

Depth

Height

Column Detail

Column setback 2- 4 from Vertical



Structural Engineering Detail

The following chart is a simple easy to follow ready-reckoner for you to use. All the steel sizes are industry standard and should be readily available.9

Reading the Chart

To use the chart firstly determine how long the longest side of your shadesail is going to be. Then, reading across, check the column size you will need. If for example you are installing a shadesail which is 6 x 7 metres you will need columns which are 114.3 x 4.5 CHS. 114.3 refers to the outside diameter of the pipe. 4.5 refers to the wall thickness. Next check the footing for hole size you need to dig. In this instance the diameter of the hole would be 400mm and the depth would be 1350. Finally check to see what the maximum allowable height of the high column can be.

STRUCTURAL DETAIL CHART COLUMN SIZE FOR SHADECLOTH SAILS CIRCULAR STEEL POSTS

Square/Rectangular shadecloth sail with the longest side up

to:

Column Size Footing Size Dia x Depth in mm

Maximum Column Height above

ground in metres

4 metres 101.6 x 4.0 CHS 400 x 1050 2.8m 7 metres 114.3 x 4.5 CHS 400 x 1350 3.25m

10 metres 139.7 x 5.0 CHS 500 x 1500 4.0m 12 metres 165.1 x 5.0 CHS 600 x 1700 4.4m

**Notes on Column & Footing Sizes:

All columns to be of C350 grade Circular Hollow Sections (pipes). All columns should be galvanised steel. Typically the low post will be set at 2.2m AGL (above ground level) Engineering is for W30 wind regions. Typically this is suburban regions not in

cyclone areas and not located in exposed area or hills. Footing detail assumes firm natural ground. If digging into backfill or uncompacted

soil, the footing sizes will need to be increased Columns supporting double connections should be increased to the next size column

and the diameter of the hole should be increased by 100mm.

9 If you require specific engineering details to submit to Council contact: [email protected]



If you would prefer to use square columns (SHS) instead of round columns (CHS) refer to the chart below. The same constraints as the previous chart apply.

STRUCTURAL DETAIL CHART COLUMN SIZE FOR SHADECLOTH SAILS SQUARE HOLLOW SECTION

Square/Rectangular shadecloth sail with the longest side up

to:

Column Size Footing Size Dia x Depth in mm

Maximum Column Height above

ground in metres

5 metres 75 x 75 x 5 SHS 400 x 1050 2.8m 8 metres 100 x 100 x 5 SHS 400 x 1350 3.3m

10 metres 125 x 125 x 5 SHS 500 x 1500 4.0m

**Notes on Column & Footing Sizes:

All columns to be of 350 grade Square Hollow Sections (SHS). All columns should be galvanised steel. Typically the low post will be set at 2.2m AGL (above ground level) Engineering is for W30 wind regions. Typically this is suburban regions not in

cyclone areas and not located in exposed area or hills. Footing detail assumes firm natural ground. If digging into backfill or uncompacted

soil, the footing sizes will need to be increased Columns supporting double connections should be increased to the next size column

and the diameter of the hole should be increased by 100mm.

Important Safety Note: Shadesails are not designed to be installed in areas where extreme weather events such as very high winds, snow or hail are likely to occur. Such circumstances can cause structural failure as well as irreparable damage to the shadesail itself. In the instance where an extreme weather event is likely or predicted, the shadesail should be removed ahead of time

Ordering The Columns

The best way to do this is to contact a steel merchant in your area and have them cut the columns to the length you require. Order the knock-on metal caps from the same steel merchant.

If you are happy to go with just galvanised steel columns you can arrange for the steel merchant to deliver them directly to you. If however you would prefer to match the colour of the columns to say the existing fencing then youre probably going to want to consider getting them powdercoated.

Powdercoating is a process where by an electrical charge is applies to the metal and then a powder is sprayed onto the steel and baked on. It give a long lasting result and also makes the whole job look better. In this instance, you will need to co-ordinate with the steel merchant to deliver the columns to the powdercoater. Make sure your columns are drilled before they are powdercoated (refer below). Once the Powdercoating has been done you will then need to have the powdercoater deliver the finished columns to the job-site. Not all powdercoaters offer a delivery service.



Equipping the Columns

The final thing to do in readiness for installing the columns is to fit or equip the columns with the eyebolts and anti-twist/anti lift bars and top caps.

The easiest way for the DIYer to fit the eyebolt is to use an Eyebolt with Collar assembly. Drill a hole approximately 40mm from the top through one face of the column and fit the eyebolt. You can now fit the knock-on cap.

Refer to the Turnbuckle and Hardware Table further on to select the appropriate sizes.

The anti-twist/anti lift bar is important because it helps lock the steel column into the concrete itself. Drill a hole approx. 300mm from the bottom of the column and insert the rod. Use a heavy duty rod of at least 12mm dia galvanised steel here. Make sure the rod is tight in the hole and doesnt fall out when youre lowering the column into the hole.

Digging the Holes

Before even starting to dig the holes, it is absolutely imperative that you determine if there are any underground services in the area. This can include sewerage lines and other pipes as well as telephone and electrical cables.

WARNING: NEVER DIG BEFORE ENSURING THE AREA IS CLEAR OF CABLES AND PIPES

There are a number of ways to check this.

Do a visual check. Follow any pipes, cables or conduits and see if it looks like they are going to be in the vicinity of where you want to dig.

Review the plans of the property. Often times they clearly mark where the pipes and services are.

Contact Dial Before you Dig 1100.com.au10. This is a free service and can be a useful tool to check where underground services are located.

Contact an underground detection service company. They use sonar and other devices to locate where pipes and cables may be located. This is a paid service but if you are in any doubt as to the location of cables or pipes it is well worth it.

At the end of the day, exercise extreme caution when digging into the ground. Not all services give accurate readings and cables and pipes tend to be in the most

unexpected places.

Getting the holes wrong for their columns is the probably the second most common mistake people make and the main reason that amateur shadesail installers end up with wonky columns and sagging sails. They simply dont realise how much force shadesails actually generate, especially when its windy. Ive see it so many times where the

10 Relevant to Australia only. Other countries will have different organisations to perform these

functions.


2012

diy shade ebook

Documents

shadesail design

diy shade shadesails

types of shadesails

uvr block vs shade factor

shade cloth fabric

vs custom

uvr facts

local planning permission