Remember tension is the shade sails friend - they must be very, very tight. This depends on where you want to attach it and the construction material. If you want to mount it very high, from the roof, it is possible to use specially made Shade Sail Anchor (Roof Extenda Bracket) (https://www.shadeaustralia.com.au/roof-extenda-bracket). If you are mounting to a fascia board, use a four-hole eye plate so the load is spread. Please remember that a lot of tension will be exerted on the mounting point and in high wind situations could rip off the fascia board unless properly secured - we recommend using a long-threaded rod anchoring the fascia board back to a strong internal roof joist. If mounting to a wall also use four, or even six, hole eye plates. If the wall is cladding and you will be bolting or screwing through to joists behind the cladding always be mindful of it being strong enough. With brick, stone, or concrete secure bolts using CHEMICAL INJECTION ANCHORING. In all instances we suggest you use marine grade stainless 316 for fittings.