How do I install a pre-hung door in a thick exterior wall?

Question

I live in an old DC rowhouse; it was built in 1908. I'd like to replace the house's two slab-hung exterior doors with newer pre-hung models with full-length lites to increase the natural light and to get rid of the gaps around the doors.

The problem is that I don't know how to go about installing a pre-hung door in walls as thick as ours. Instead of 2x4-framed walls, which would be a cake walk, we've got 13-inch thick walls, and that's before you get to the siding. On top of that, the front door has a transom window with only about a 1-inch plank between the top of the door and the bottom of the transom's glass.

How should I go about getting a pre-hung door installed here? Any tips?

Answer 1

This is not an easy question. I would have to know the actual dimensions of the existing opening and a better look at the whole door frame. In most cases, I'd be tempted to gut the opening and reframe it to accept a new pre-hung. In your case you need a pre-hung without trim as you will need to install extension jams and finish it out. The door should be mounted fairly close to the interior and have the excess outdoors. This is not a real difficult job, but definitely not for an inexperienced DIYer. There is going to be framing, water/weather proofing, squaring/installing the door, and finish work. You will definately need a circular saw, table saw, 4 or 6 foot level and some air guns would be nice to have to make it a lot easier.