Quote Originally Posted by buffalobo View Post
If staples over penetrate even slightly they pull thru easily. If shingle gets any lift from wind the staple will pull thru.

Staples are bad idea all around for shingles.

There is a reason roofing nails have oversized head and warnings not to over penetrate.
The .gov answer is to use even more staples to prevent this from happening because they bought 19 billion of them at a reduced cost.