Mac Haynes
We constructed a 10 x 12 using 4 x 4 pressure treated wood and found the materials to be excellent and the instructions to be very helpful. Unfortunately we are located on a windy shore so the first big wind caused the clips on the shade sail to fail. No problem though - we checked with some other local installations and found a solution. We wrapped the straps around the 4 x 4 beams and secured them with screws and washers. (See photo)
Hopefully this work around will help some other customers with similar problems.