Shade sails, an effective and affordable shading solution, create an inviting outdoor space for relaxing or entertaining. Shade or sun sails come as squares or triangles and are often hung in multiples. When planning where to hang your sails, remember that the position of the shade will change as the sun moves across the sky. Shade will only be directly under the sail during midday in mid-summer.
Select the location for your shade sail. Consider whether you will be able to use an existing building or perhaps a concrete wall for one or more attachment points. Then determine how many posts you need to install.
Make sure the attachment points of existing structures are strong enough to hold a sail. Purchase as many four-inch steel posts as needed so you'll have an attachment point for each corner of each sail you wish to hang.
Decide where and how high you want to hang your shade sail. You may wish to have some corners higher and others lower. An 18-degree slope, for example, enhances the sail's appearance. Consider also that two or more sails will look better than just a single one. Plan for a distance of at least 10 percent of the length of the sail between the mounting point and the corner of the shade sail.
For attachment points on a wooden building, secure an eyestrap with two lag screws at the desired height. For a concrete wall, epoxy a three-eighths-inch eyebolt to the wall. Screw a three-eighths-inch eyebolt near the top of each post you plan to erect.
Dig holes where you need to place posts. Make the holes about 14 inches round and as deep as needed to bury about a third of the length of the post.
Line the bottom of the hole with patio pavers so the pole has a solid pad to sit upon.
Put a hold-down bolt through the lower part of the post so it will remain secure.
As you hold the post straight upright, have someone pour concrete to fill the hole. Make sure concrete is packed well and that a slight angle on the poured concrete surface encourages water to drain away from the post. Support the post as the concrete dries.
Wait two days before installing the sail to make sure the concrete is fully set. Attach one corner of the sail at a time to its attachment point with a turnbuckle. Use chain or steel cable if you need added length to reach an attachment point.
After all the corners are up, tighten the turnbuckles so the sail is free of wrinkles and has an even amount of tension across the whole sail.