Install Shade Sails continued....p2
Turnbuckles
The size of the shade sail is juristic of how many turnbuckles should be used . The table below clarifies this matter.
Sail Area |
Min Number of Turnbuckles |
Up to 20 m 2 |
1 |
20 to 40 m 2 |
2 |
40 - 50 m 2 |
1 per sail corner |
The size of the turnbuckles used is another scaled factor:
Shade Sail Area |
Turnbuckle Size |
20m 2 |
min 6mm |
20 to 40m 2 |
min 8mm |
40 to 50 m 2 |
min 10mm |
Important note: when installing turnbuckles for shade sails it is imperative that you use lanolin or some type of anti-seize compound on the thread before you tension the shade sail.
Roof Post Installation
Locate a tile near the desir ed position of the post and remove it, to then locate the roof members. This method is not recommended for shade sails larger than 30 m 2.
The Roof post is bolt ed to the roof members. It should be install ed vertically from the centre of effort as shown. The Roof Post should be construct ed with 50x50 4mm SHS Steel, and a cap to suit. A 50mm vent-pipe flashing is installed on the roof line, and should be sealed well above and beneath with good quality silicon that has ±25% elasticity.
To cut the hole in the tile for the 50x50mm S.H.S roof post it is advisable to use a 100mm diamond saw blade.
For extra bracing, a 75mm x 35mm piece of timber can be bolted across neighboring roof trusses as shown to eliminate sideward stress on the ceiling joists. Where the shade sail is subject to possible high wind conditions, the roof post should be mounted directly above an external wall.
Ensure that adequate tie down (triple grips or straps) of the roof members exist where the roof post is install ed . Occasionally a roof post that protrudes higher than the recommend ed 300 mm is requir ed . Install with two guy wires attach ed with rafter brackets (refer Fig 2c) or 120x10 screw eyes to support the additional leverage. The diagram below demonstrates the rafter bracket method.
Alternatively, a custom made roof post that fits between the rafters can be used . Access to the roof space needs to be gained to measure accurately the space between the trusses where this type of bracket is to be install ed . Also the roof pitch has to be determined for fabrication
Flashing of roof posts is by way of lead collars for tile roofs and deck tight for metal roofs. Ensure that all holes in the post itself are seal ed and the post is capped .
Rafter Bracket Installation
The rafter bracket is a much more convenient way to perform a roof fixing, however care must be taken to avoid roof leaks. We do not recommend the use of the rafter bracket when erecting sails larger than 30m 2 . Always use high flexibility silicon, and seal the top of the thread in the eye-nut as well as a thorough coverage of the tile penetration.
Remove tiles in the desired area of the roof, and then locate a roof member. The Bracket must be installed on the side of the rafter opposite to the pull of the shade sail as shown below.
Use a 12mm glass cutting spade bit followed by an 18mm masonry drill bit to achieve the hole in the tile for the 16mm rod. Use two 10mm Bolts to bolt the bracket securely to the rafter. Wood screws can be used in the additional 5mm holes to hold the bracket in place whilst drilling the holes for the bolts.
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