Are shade sails waterproof? Do they block rain and stop it coming through?

Standard shade cloth is not waterproof. It is woven to block a high percentage of UV radiation and reduce heat, but it will let rain through, and heavy rain will come through faster than a light shower. This is by design: shade cloth needs to breathe to stay cool, and a fully sealed fabric would trap heat underneath it.

If you want a shade structure that also keeps rain out, you need a waterproof PVC fabric rather than mesh or shade cloth. As WeatherSafe WA explains, both shade cloth and waterproof PVC block UV effectively during summer, but PVC has the added benefit of keeping you dry through winter too, which is why it is the choice for anyone wanting year-round outdoor use. Because PVC is heavier and carries more wind load than shade cloth, the frame and footings supporting it are usually built stronger, which is reflected in the price. WeatherSafe WA’s Shade Sails for Pool range specifically uses waterproof PVC where all-weather cover matters, such as over a pool or entertaining area.