sue141452:

Your nails must hit the framing underneath the drywall; where you place them is less important.

I usually go into the first groove in the molding to obscure the nail heads even more. I'd hot-melt my miters together first because if the jamb and drywall aren't in perfect plane, and they usually aren't, it will make uneven miters. Don't overnail and don't be afraid to shim and caulk. Less is more here, it's just trim.

This post was edited by Trebruchet on Fri, Apr 25, 14 at 16:24

Use 6d galvanised or stainless finish nails for the bathroom in my opinion as by the time a 4d goes thru the trim and drywall there is not much to hold in the wood.

Thanks, I have some, I'll do that.

Trebruchet, just noticed my response to you didn't get posted. I'll do what you said to the miters, sounds like a great idea, thanks!!

You want the 4d into the jamb, 6 or 8 into the drywall. For mitered trim it helps a lot if the drywall is slightly proud of the jamb, that tends to tighten the miters; if it is the opposite the miter will open when you nail into the drywall and framing behind. If the jamb is proud first nail all around in to the jamb with your 4d nails, after your miters fit well, then shim firmly against the drywall behind the miters before nailing the outside.