Roof Tin Canning

It could be both of them, the plywood deck could also be a factor. The steel supplier could have caused it, or the coater or the slitter. There are many causes of oilcanning. The stance of most manufacturers is that oilcanning is not a cause for rejection. That being said, there are things that could have been done to reduce the visual impact; such as stiffening ribs in the flat area of the panel, embossing of the metal. Precision leveling the metal prior to forming. Shimming the deck if need be. Creating a crown in the panel using backer rod. Oilcanning issues are in the eyes of the beholder. We had one customer that said there was not enough oilcanning. Feel free to post again or call me at 610-395-8445