3 Keys to Tensioning a Shade Sail
As you can probably guess, tension is key to the functionality of tensile fabric shade canopies. Without it, shade sails sag or droop, especially in the centers, affecting the aesthetics and longevity of the sail. Introducing tension to a shade sail, however, isn't quite as simple as just pulling it tight at each corner. We focus on three main tensioning techniques:
1) Perimeter Wire Rope
2) Height Variation
3) Tensioning Hardware
This article is the first of three that will explain how each of these techniques work together to provide a great looking and long lasting sail.
Do you need to use wire rope?
Yes. Wire rope is an essential part of our shade sails. Without a wire rope around the perimeter, tension applied at each attachment point is not distributed evenly in the sail, creating areas of concentrated stress around the corners. This causes the center to sag and increases the risk of tearing at the corners.
When a wire rope is used, the pulling force from the attachment hardware is transferred to the wire rope, rather than directly to the fabric. That force is then distributed throughout the perimeter of the sail, where the wire rope runs through a pocket. As the curved edges of the sail are pulled taut, the wire rope and fabric attempt to straighten out, which pulls the center of the sail up and fights sagging.
All this being said, perimeter wire rope alone is not enough to do the trick, especially in large custom sails. Don't forget to learn the role of height variation and hardware in tensioning a sail over the next two weeks!