Hello everyone! I started building the 1st of 2 helix today and figured I would show some pics. This pic is of the luan cut and on the floor being glued together. It's 2 layers thick making it a total of 1/4". The over all diameter is 77" with radii 36" and 33 1/2". I am climbing 19" with 5 loops which should give me roughly a 1.7% grade on the outer and a 1.9% on the inner track. Double check my math please because I make mistakes alot! I got the idea of overlapping the luan from somewhere online but cannot find it in my favorites bar.