Shade sail project

In 2006 we moved into a new house on a 2 ha paddock block. The block had no trees at all and I had a whole lot of children who wanted to play outside in all sorts of the weather. The weather range in the New England of NSW is a winter of below 0 (degrees Celsius) with wind gusts that will blow a grown man off his feet and a summer where the temperature climbs up to 40. I realised that the trees I planted 2006 would not grow up high enough to cause shade till the children were adults. A shaded play area was required and it would have to with stand the most extreme weather conditions. 

I put my brother and father (both engineers) to the task of designing the structure. They designed a six pole shade sail structure. The six poles were angled out from the ground to provide strength and the poles were different lengths to hold the shade sails tight (see photo).

I ordered six square metal pole with an extra 1 metre on each pole to secure them in concrete filled holes. I marked out where I wanted the holes and a friend with a bobcat drilled six holes (1 metre deep and 450 mm wide). I then drilled holes for the chain eyelets and screwed the weather caps to the top of the poles. I did this before putting the poles into the ground as it was a lot easier to work on them while they were on the ground. 

Now came the tricky part I had to form up the poles to pour the concrete. I used some old form work boards and large clamps to hold the poles. As each pole needed to be angled out from the ground I had to form all the poles up at the same time to line them all up by eye. Once the form work was finished the shovelling began. Lucky for me I had got an electric concrete mixer for this. After a day of mixing and pouring and a couple days allowing the concrete to set the poles were very strong. 

I then put two shade sails up with strong chains and a set of turn buckles for tenioning onto the eyelets. Then the job was done.  I would recommend that what ever parts you look at getting always buy the heaviest duty parts you can get do not underestimate the strenght of the wind