It'll blow out, especially with a spring coming up. A customer bought a three panel 8x12 set. Did the 3mm cause it was a 3-6 month project. He put them in a metal frame with support bars behind it. The wind came in from behind and knocked a panel out. Ripped at the fasteners, likely due to the holes being too close to the edge. Granted it was Texas tornado producing winds, and even then, the other two panels were fine. Signs were down all over the area. Though I do believe 6mm would have survived.