Unless you can demonstrate to your local building code office that your homemade shingles will comply with the CSSB "Grading Rules for Wood Shakes and Shingles", you will likely not be allowed to use them and will not be issued a permit to install them.

http://www.cedarbureau.org/faq/product.htm

I guess I could have mentioned that I live in small town Montana, where building codes are never enforced and rarely exist. The cedar planks will basically be for aesthetic purposes only, so it seems they would work fine for my application. I just hope there's not something obvious that I'm overlooking.

Well, Montana has mandatory building codes statewide regardless of whether or not they appear to be enforced:

http://www.discoveringmontana.com/dli/bsd/bc/build_info2.asp

Making your own shingles for your own residence is not allowed under the IRC code that Montana uses because the grade of the shingles cannot be guaranteed not only for you, but for the next fellow who may own your house.

Now, if that doesn't bother you, then you could probably go ahead and do whatever you want and the other 4 state residents probably will never know.

Just hope one of those other 4 guys doesn't buy your home because I hear y'all carry guns and like to settle personal disputes the way you build homes:

The OLD way with no rules or regulations but yer own! :)

"Now, if that doesn't bother you, then you could probably go ahead and do whatever you want and the other 4 state residents probably will never know.

Just hope one of those other 4 guys doesn't buy your home because I hear y'all carry guns and like to settle personal disputes the way you build homes"

I came here for building advice, not to hear stupid stereotypes. Forget I asked.

Well.

I may fail at comedy and humor.

But my code advice was correct.