I need suggestion on how to put up a triangular sun shade sail over my balcony. There are already two pre-drilled holes on the wall where I can hook up the two corners.
Now is the third corner of the canopy. My old plan was to attach it to a pole and affixate the pole somewhere on the balcony railing. The pole has to be tilted slightly outward, I used a bamboo pole and placed it behind the planter, but it was never sturdy when the wind was strong, and it has already snapped.
This is an illustration from the side of my balcony (forgive my drawing)
This is the railing. The parasol holder is where I want the pole to stand but can't think of a way to hold a pole with it at tilted angle sticking outward.
And the two other corners of the sail see below. Ideally I'd like to tuck them away like this behind the pigeon spikes when I'm not using the balcony. The sail is 3m x 3m x 3m, but the balcony is not that wide, hence the third corner will be a little bit out.
Would it be possible to utilise the parasol holder to hold a pole at a tilted angle. Perhaps with the help of small gadget such as fishing rod holder? I don't know much about the maths of how much wind the sail can take if the pole is put up like that… I want to use a pole because my balcony is really tiny, and I want to avoid things like sand/water base…
Thanks for reading this, any suggestions welcome 🙂
Best Answer
Generally speaking, when the wind gets behind a sail, it exerts considerable force. People have crossed hundreds of miles of ocean with no more than 3m x 3m x 3m.
If you manage to affix the corner of the sail firmly to a sturdy pole and affix the pole immovably to the railing, you may be rewarded with the sight of sail, pole, railing, and all soaring off over the courtyard. Even if it doesn't actually break, your landlord is not going to be happy about what happens to that railing.
I checked some online introductory sail and rigging tutorials. According to their calculations, if a gust of wind is deflected by your building and strikes your sail nearly upward (or downward) at about 35 mph, the force exerted by each corner of the sail upward (or downward) would be about 200 pounds.
The structure that is least likely to damage your balcony is a full pyramid. Find two rigid lightweight poles each 3m long, attach them together at the ends, and form them into a triangle based at the pre-drilled holes. Prop up the free end of the triangle with a third pole, with its bottom attached to the base of one of the railing stanchions.
Attach the outer corner of the sail to the place where the three poles meet.
Do not brace the vertical pole against the railing. Let its motion be constrained entirely by the two poles along the sides of the sail.
Note that whatever fixtures you install at the locations of the pre-drilled holes will also have to hold against momentary upward (or downward) loads of 200 pounds.