Plywood type for roof

[mechmagcn]

I have read threads here where folks are having problems with bending luan plywood for the roof of a tear. I decided to try using 1/4" pine BC ply and it bends easily. Is there a reason everyone uses luan or is it just a visual thing? Mine will be covered with a EPDM rubber roof membrane, so looks is not a consideration. I even looked at the 1/4" birch offered at the local box store, but it wouldn't bend any easier than the luan.
When I get started on the interior, I want to use 1/4" birch beadboard paneling. I don't know if it will be possible to bend this for the inside curves on my roof. Has anyone had any experience using this material?

[mikeschn]

Hey Jeff,

I think a lot of people buy the luan based on price, and the fact that it's nice and flat in the store. I've seen the 1/4" BC warp like crazy.

But I am using Birch, cause it has a nice smooth surface, since I plan on painting with Uniflex 255.

I've seen a number of people use paneling, but I don't know what the thicknesses were.

Mike...

[Jiminsav]

I used luan because the glue in it is so water resistant that I've had a piece outside for 3 years unprotected and it's not separated the ply's or rotted.
I used 1/4 inch pine plywood on the bottom, and it separated between the ply's the first humid day.