We did a very similar trim and did not nail in that location you are pointing to. We did nail the trim board up into the header between the casing. We did not use glue. been a month or so and so far so good, lol

If you want to add some nails, I'd go down from the top at an angle.

I wouldn't, you risk splitting the wood and give yourself another hole to fill for no particular benefit. If I were building the header up piece by piece I might well nail down from above when attaching the small bottom piece. When I did mine I assembled the headers completely on the bench and then installed them as one piece, nailed only into the door framing.

Ok I wasn’t sure if it was necessary. Since it is a bathroom, I did add a bit of glue. I was wondering since I’ve seen others do biscuits or pocket screws in these butt joints. Not sure if it was overkill or not.

I have a Ryobi cordless 18 gauge brad nailer and I've found it really useful for these type of trim jobs. Max length of the brads is 2", so it is sometimes able to go through everything and into the 2x4 behind the trim to really hold it. The hole left by the head of the brad is very small, and much easier fill and paint over than the head of a nail.

Bruce

If you glued the joints, that should be enough. Brad nails would have been fine if you nailed together as it was assembled, but now that everything is in place the angle you'd have to nail at is a bit weird and could risk splitting as someone else mentioned. I'd probably just leave it this go around.

What is the material you're using? I've used MDF around my house and found that my miters open up in the winter when the material contracts. So I don't think reinforcing butt joints is totally pointless. If I could re-do mine I'd use biscuits and glue.

Thanks Nick. I’m using pine since it’s a bathroom. For the future, I’ll be trying pocket screws and glue.