Currently installing a 3" prefinish (dark brown)engineered product in a very long hallway. Approx 6' wide by 30' long.Glue down installation over concrete and cork underlayment. Strong natural light source on both sides. Flooring is running the length of the hallway. After installing a few rows there appears to be an inperfection in the surface or finish. On several planks, there seems to be a line or wave that reoccurs every 4-6 inches across the width of the plank. The planks are perfectly smooth and the wave is not noticed when looking at from a bird's eye view. When looking at it from each end of the hallway, it looks dreadful!!! In my experience I believe the problem to be a roller mark from factory finishing. I've halted installation and notified the distributer. Anyone else come across anything like this??? Thanks.

Yes, this is a complaint we see often.

Sometimes in the finish, as roller marks, sometimes the widthwise bands are telegraphing the ply beneath the surface.