A number of customers walk through the our factory door and enquire about a triangular shaped Shade Sail but the triangle is not the ideal shape for most applications. Only on the rare occasion is the triangle shape necessitated by a small courtyard or some other triangular shaped area. It seems that most people’s idea of Shade Sails comes from depictions of them as triangles (our own logo features triangular shapes) but in most case what they have actually seen is t whereas it is in fact the illusion that a Hyperbolic Shade Sail creates.
A Hyperbolic Sail is a four sided, four post ShadeSail with two diagonal posts placed high and two diagonal posts placed low. This shape is optimal as it creates an even wind load above and below the Sail but when seen from a distance one post can appear to disappear over the horizon of the Sail and give the appearance of a triangle.
Our company sells ShadeSails to the public but we also wholesale to the the ShadeSail industry and we find that we make very few triangular Sails if any. This is especially the case for custom Shade Sail projects. By the time you cut the catenary curves in to the Sails perimeter (which are needed to keep the Sail tight) you don’t finish up with enough coverage to meet the requirements of the job. The depth of the catenary curve is based on a percentage of the distance between the Shade Sail posts so this is especially bad when the triangle is much longer than it is wide. When a ShadeSail is being designed the ShadeSail designer needs to take in to account the direction and height of the sun, which normally means look out fot the northern sun lower in the sky later in the summer and of course the low western sun in the afternoon.With a larger area that can be covered by a four sided ShadeSail it is easier to provide protection from the sun as the Sail shades a wider area. So while triangular pre-made sails are popular with do it yourself enthusiasts, we will rarely if ever recommend them for projects.
Four sided shade sails are much more effective and this is why we don’t usually recommend triangular Sails