Lap Siding for a Flared Turret

Those complex Victorian turret flares are usually shingled because siding them with boards is so hard. But here's a description of how to fit lap siding to a flared cone. March 4, 2007

Question
I'm restoring an 1898 Victorian that has a round turret finished with 1/2 x 4 cedar lap siding. The bottom 3 courses are flared out. How do I get those courses to conform?

Forum Responses
(Architectural Woodworking Forum)
From contributor A:
You've got your work cut out for yourself on this one. These areas are usually shingled because of the difficulty. If you want to plank this area, you must do it like a boat. If you want more info, check out a boatbuilding book on how to spile a plank. You need a cedar board that is wider than 4". 12" would be about right depending on the radius of the curve. Tack this plank onto the building and let the ends run up and lay across the area where the siding will be. Take 2 battens, say 1/2" by 1/2", and tack these onto the wide cedar board on the same lines that represent the top and bottom edges of the siding. Mark these lines in pencil and remove the wide cedar plank. Cut these lines, trim the ends to land on a stud, place the new plank in place and nail. The plank will look like a banana and you will not believe that it will fit, but it will.