I have a small rental house that has very nice interior woodwork. A prospective tenant has requested that I install a door on one of the rooms. The door jamb is very nice and appears to have been installed with a door in mind, but one was never installed. The jamb does have a center stop on the top and sides and appears to be a rather standard size - a bit over 80" x 30" - and very close to, if not exactly, square. I have installed prehung doors before and have replaced a standard door with one from the same manufacturer, but have no experience with just installing a door in an existing, but unprepped jamb. So I have two questions: 1) How do you determine door size relative to the finished opening? 2) How do I best go about installing a door like this? I thank you in advance for any help you can provide. Thanks Anthony

I recently gutted my basement so I could update walls, floor and ceiling. I left the framing up since the studs are in good shape. The ceiling is very low so I need to take into consideration when installing the doors. The one thing I noticed is that the studs are 2x3s. The pre-hung door I purchased is made to fix 2x4 studs. Also, the distance between the top stud and floor is 6 feet. How can install this door when I don't have enough room for the jam at the top and when the studs on the sides are to small? I'm new to this website and not the handiest person so I apologize in advance if I'm not making sense.