I just finished framing a conical tower on a custom home we are building. The tower is 17′ H (measearing from the top of second floor plate up) and the pitch is 36/12. The lower 3′ has a “flip” scabed on to it. The plans call for 3X layer of 1/4″ ply grain vertical, staggered seams. The problem is how to sheath the lower flips. If it is a conical until that point and then it flares out, it seems that I would need to cut kerfs in order for it to lay correctly. As it was we had to modify the plans the architect and engineer gave us just so we could have a true conical.
Thanks
Replies
Say you had an imaginary sheet of the 1/4" ply 17' long. If you cut it to go from top to bottom, including your flare, each piece would be a long skinny triangle but at the bottom, the sides of the triangle would curve inward. That curve would be a function the curve of your flare. In other words, where the pitch is constant, the edges of each piece of sheathing will be straight and where the pitch changes, such as at your flare, the edges of your sheathing must be curved. The trick, of course, is getting the math right. I can't help you with that but I know a book that probably can. "Geometry for the practical worker" by J.E. Thompson. Or some other similar book. Maybe challenge a local college professor to do the math for you.
Best of luck with your project.
John
Cyber,
Descriptive geometry was my favorite coursework in college. At my old job, I worked out templates to join large pipes which were intersecting at oddball angles. Anyway, I'm sure I could help you here, but I need to understand what you mean by the "flips". Could you post a picture?
Ragnar
how about using 1x boards for the flare part.