I'm preparing to install gutters, but I've noticed that rain just flows down my fascia boards. I anticipate having a problem with water going behind the gutters. I saw this Q&A, but the solution I'm considering isn't mentioned there.
This site argues that there's supposed to be a wooden strip behind the metal drip edge, to force the water to fall from the corner instead of flowing down the fascia. This makes perfect sense to me, but at the same time, I'm a little skeptical because this is the only mention of it I've found. (The reason nobody does this, they say, is because roofers don't do carpentry.)
So my question is, would it be a good idea to try to retrofit my roof with these wooden drips? If so, is there any reason I shouldn't reuse the existing metal drip edge?