How to Install a Shade Sail

Once you’ve chosen the area for the shade sail, determine the number of shade sail anchor points and posts you’ll need. Measure the length, width and height of the area where you’ll install the shade sail. In this installation, we’ll be using two shade sail anchor points and one pole in the ground for a 3-point triangle shade sail.

When you’re installing shade sails, they’re going to be under a lot of tension, so use manufacturer-approved mounting and tensioning hardware rated for the expected loads. Decide where your first corner is going to be. Locate an approved structural attachment point, such as framing identified by the shade sail manufacturer’s instructions. Never fasten shade sail hardware only to siding, trim, sheathing or unsupported fascia. If attaching at a fascia, use an appropriate support designed to transfer the load to the roof framing.

Next, using your eye plate as a guide, measure and mark where you need to drill. Once you’ve marked the locations, predrill holes for the eye plate. Once you’ve predrilled the holes, attach the eye plate securely to the house.

Attach a turnbuckle to the eye plate and attach one corner of the shade sail to the end of that turnbuckle. 

Attach a second turnbuckle to the second corner of the shade sail and stretch the shade sail to the far corner where you want to anchor the second eye plate. Stretch it tight to get the tension out. Rotate the turnbuckle body according to the manufacturer’s directions until the sail reaches the specified tension.

Mark the eye plate to match the location of the first eye plate (measuring for accuracy). Once you’ve marked the locations, predrill holes for the eye plate. Once you’ve predrilled the holes, attach the eye plate securely to the house.

When you don’t have a structure to attach your sail to, you can use a pole that you’ll embed in the ground with concrete. Attach the shade sail and turnbuckle to the pole at the correct height. To secure the pole in the ground, you’ll need to cut into the dirt, cement or turf, dig a hole, pour concrete into the hole and then mount the pole. Set attachment points at the elevations specified by the manufacturer so the sail sheds water appropriately. Don’t confuse sail pitch with any required post lean. The required height difference varies by sail design and size. Move the pole out until you match the tension of the other anchors. That’s where you’ll dig your hole.

Dig the footing to the dimensions specified by the shade sail or post manufacturer. Required footing depth and diameter depend on the sail size, post height, soil conditions and expected wind loads. Don’t use a fixed footing depth for every installation.

Contractor Consideration: Shade sails can place significant loads on posts and structures. For large sails, tall posts, questionable soil conditions or installations in high-wind areas, consult a qualified builder or structural engineer.

If required by the footing design or soil conditions, cut a concrete form tube to fit the height of the hole and place the tube upright in the hole. Pack some of the dirt you removed from the hole around the outside of the tube to ensure that it’s solidly in place.

For our installation, we’re using fast-setting concrete. It’s ideal for posts and sets in about 20 to 40 minutes. If you’re installing the pole by yourself, you can mix the concrete, pour it into the tube and then set the shade sail post in the concrete. However, if you have a helper, you can put the post in first. One person can hold the post in place while the other pours the concrete. Add a small amount of water to a bucket, add the concrete mix and then mix. To mix our concrete, we used a heavy-duty single-paddle mud mixer. Choose the best mixing method that works for you.

Not all fast-setting or post-setting concrete requires pre-mixing. For post holes, you can pour the dry mix straight from the bag into the hole and then add water. Be sure to read the bag instructions for proper use.

Pour the concrete into the concrete form tube. Place the pole in the concrete, checking that it maintains the position and angle specified by the manufacturer as you go. Position and brace the post at the angle specified by the shade sail or post manufacturer. Some systems require a vertical post while others call for the post to lean slightly away from the sail to resist tension. Keep adding concrete and tamping it down with a trowel as necessary until the concrete is level with the ground and the pole maintains the specified position and angle. Keep the post braced and wait the full time specified by both the concrete manufacturer and shade sail manufacturer before tensioning the sail.

Once the concrete is cured, you’re all set. Attach the final turnbuckle to the D-ring on the shade sail post. Tighten the turnbuckle, but not too much — just enough to get rid of any wrinkling or sagging. Check the tension on the other turnbuckles. 

Over time, the shade sail fabric can stretch. If it does or you want to add more tension for a taut appearance, carefully tighten the turnbuckle according to the manufacturer’s instructions. Do not overtension the sail. Once the tensioning is complete, the shade sail should be wrinkle-free with no sagging in the middle.