Your Ultimate Guide to Shade Sails

The Need for Shade

With the rise in average global temperatures and increase in skin cancer, the demand for shade is increasing. Many community playgrounds are now requiring shade structures to protect children from the sun. Homeowners need a cost-effective way to keep their pools from overheating. Backyard patio areas can be transformed into outdoor rooms with the addition of shade.

All of these applications have one thing in common: they are large spaces that can all be protected with shade sails (also called sun sails). Sun sails provide protection from harmful UV rays. These sun shade sail canopies work great as pergola and outdoor patio shades. This makes them perfect for outdoor shade in outdoor living and party spaces.

Shade Sail Design Software

Due to the large sizes and odd shapes involved in most shade sails, many fabricators use a shade sail design software. Trivantage^® has teamed up with Meliar Design to create an interface between Awning Composer^® and MPanel Shade Designer that allows fabricators to visualize shade sails.

The Shade Designer software uses basic dimensions like length, width, and pole height to create a three-dimensional object. The object can then be exported and superimposed over a site picture in Awning Composer. You can choose from different fabric options, colors, and poles to aid in the final design decision.

Once the customer approves the rendering, the MPanel software can be used to calculate the compound curves for the shade sail. Some shops run these dimensions into a cutter and create kraft paper patterns that they tape to the floor to use during the layout process. Other shops just use a dimensions report from the MPanel software and mark a pattern on the floor with tape.

Cutting the fabric panels on an automated cutter is not very practical since the width of most shade cloth exceeds the width of the average cutter. The fabric is also very slippery and because it is mesh, it does not lend itself to being held down by air vacuum systems on most cutters.

Determining Loads

All shade sail footings and attachment points must be designed by a certified engineer that has experience in calculating shade sail loads. Due to their large size, these sails can develop large point loads on each of the connection points.

When applying for a permit to install a shade sail, building inspectors will want to see the calculations that went into determining these loads and how the poles, footings, and connecting hardware will deal with these loads.

Engineers often use specialized software for these calculations. Stamped, engineered drawings for each shade sail job are the minimum that each fabricator should start with before building.

What to Consider When Designing

• Ideally, any one side of a shade sail should not be longer than 30–35 feet. Larger sails up to 70 feet are possible, but can be difficult to build and install as they require very large posts and footings.
• Long and narrow sails should be avoided. Ideally, the length of the longest side of a shade sail should not be more than twice the length of the shortest side. This is particularly true with triangle shade sails. The reason is that spreading the load along a narrow sail can be difficult.
• Triangles and other flat shade sails should slant sufficiently to prevent pooling rainwater. A slope of at least 1:6 is recommended. Larger triangles or flat sails require more of a slant to avoid sagging and facilitate shedding of rain.
• When installing square or rectangle shade sails, the strength may be increased by twisting the sail into a hyperbolic parabola which gives a three-dimensional stretch to the fabric. You can also achieve a third dimension by attaching one corner of the quadrilateral significantly higher than the other corners. This distribution of overall tension results in a stronger shade sail that lasts longer than two dimensional shade sails exposed to the same conditions.
• Shade sails are not intended to hold snow and should be taken down where snow is a possibility.
• To avoid chafing of the fabric, overlapping shade sails should have a minimum of 12 inches of distance between them. Otherwise, windy conditions may cause the sails to rub against each other and may damage the fabric over time.
• When fixing a shade sail to a roof or building, it is very important to ensure that the attachment point is structurally strong. Many buildings are not designed to take the stresses generated by shade sails.
• Poles are generally tipped outward, away from the center of the shade sail to provide a pleasing visual look, but they may also be installed vertically.

Building Support Poles

In all cases, the size of the support poles should be calculcated by an engineer.

Shade Sail Fabric 101

There are multiple ways to rig a sail shade, depending on the look, effect, and space requirements. How you want to create your custom shade sail is up to you, your client, and an experienced engineer.

• Shade sail fabrics are mesh rather than solid fabrics, which allows water to drain through. They are often made with HDPE (High Density Polyethylene).
• Their stretch characteristics make them easier to work with and prevent wrinkles.
• They are stronger than conventional fabrics which make them ideal for handling the stresses incurred in shade sail structures.
• They come in widths up to 12.5 feet which reduces the number of panels needed for a shade sail.
• We recommend stitching with a PTFE thread, like GORE^® TENARA^® or Aruvo^®.

Shade Sail Hardware 101

While selecting the right fabric is key, the shade sail hardware is just as important. The fittings must be positioned correctly to withstand tension and severe weather. Since each part provides an important link, care should be taken when selecting and installing your shade sail hardware.

There are two choices of hardware for installing shade sails: galvanized or stainless steel. Most fabricators prefer to use stainless due to its long-lasting properties.

System sizes

When we talk about fittings belonging to the same “system,” this represents which parts are compatible with each other. Systems come in 6mm, 8mm, 10mm, and 12mm sizes. For example, an 8mm thimble would pair with 8mm wire rope. Simple as that.