Shade Sails

Planning the span

Measure between the points you can actually fix to, not the area you want covered, and allow for the fixings and tensioners at each corner, which take up more room than people expect. Triangles suit awkward corners and shed water readily; rectangles cover more usable area for the same span. Set the corners at different heights so water runs to a low point instead of collecting.

Fixing points and tension

The load on a tensioned sail is substantial and it rises sharply in wind, so every anchor needs to be into something structural. Masonry needs the right fixing for the substrate, and a post needs to be set properly rather than driven in. Never fix into guttering, fascia board or a fence panel. Tension the sail evenly so it does not flap, as flapping is what wears out both the fabric and the fixings.

Fabric and UV

Shade sail fabric is usually a knitted polyethylene that blocks a stated percentage of ultraviolet while letting air through, which is why a sail feels cooler underneath than a solid canopy. Most are shade fabrics rather than waterproof ones, so they take the sting out of the sun without keeping a shower off. Take the sail down before winter: it is not designed to carry snow or to sit through months of gales.