I was travelling recently and my hotel room looked down on these shade sails in the playground of a local school. I thought there were few interesting design features with these sails that we could look at and learn from.
Overall the sails have been well designed and thought-out to get the best coverage for the area. This photo was taken in the middle of the day and it’s clear that the shade is falling right beneath the sails giving really good coverage. I like the way the shade sail on the left has been curved around the corner of the building so as to continue shading up the side. To do that the installer would have needed to pattern up the sails in a CAD program (Computer Aided Design) in order that the curve cleared the edge of the building. If I had been designing these sails I would have acquired some accurate plans of the area (or if not drawn them up to scale myself) and then marked on them where the columns were to be installed. From that the computer could model and pattern up the sail.
It’s interesting to look down and see the hem lines in the fabric from above. The big shadesail on the right has been made from 5 strips of shade-cloth sewn together. I’m often asked about shade sails and how many hems a certain sail will have. Most of the sails we make are made from ‘Commercial 95′ shadecloth which comes on a 3 metre wide roll so it’s relatively easy to work this out.
Another interesting design feature of these sails is the mid-point join that has been put in along the hemline.
Two shade cloth sails joined along the hemline to minimise curvature
The reason this has been done is to minimise the gap between the sails. Imagine if there was no join at this point, then both the sails would curve away from each other and at the mid-point the gap between them would be as much as a couple of metres. By adding this mid-point joint, this gap has been significantly minimised. A Note about mid-point joins is that unless they are done correctly, it does create a common failure point. On big sails like these, the reinforcing where the connections are need to be very strong otherwise the stitching can pull away in windy conditions.
A final point that’s interesting to note with these particular shade sails is that most of the corners are directly attached to the columns – there are no turnbuckles or lengths of chain. This is the domain of very experienced shade sail installers. The tension is acquired for these sails via the internal sliding cable. The shade sails are fitted loosely and then the tension is bought into effect by shortening the cable. This of course goes a long way to gaining maximum coverage of the sails by not having a ‘take-off’ at each corner but, it doesn’t leave any room for error and if the sail is even a little to big, there is nowhere to go and no way to get it tight. Essentially what I’m saying here is that for the DIY’er, I’d recommend sticking with a turnbuckle or some some chain at each corner. This give more room for adjustment, it makes the sails a lot easier to fit and, it also give room in the future to re-tension should the sails begin to sag over time.