Installing Pre-hung Doors with Rick

A few months I had new stairs installed. I asked Rick, the carpenter if he do my doors. He said he would but he's always busy and I'd have to get on his schedule. Then a few weeks later just before he was to install them, we got flooded, along with most Denver and north. Unfortunately we had our doors in the basement and they got damaged. The doors would have been fine but they put a masonite veneer over the doors and that bubbled when it got wet.

So I had to reorder the doors. I was a bit steamed since I ordered solid wood doors (primed) and they neglected to inform me about the masonite veneer. The doors were only wet for an hour or so and the jambs (wood) were fine. After a long delay the doors arrived just before the end of the year. Rick was busier than before so we didn't get on his schedule for another 1 1/2 months. I worked with Rick over the weekend to speed the job and learn something in the process. Here are my notes and some of the tricks I observed.

First pop out hinges and remove door from frame

Measure the gap between the bottom of the door and the bottom of the jamb. Determine what gap you want. I aimed for 5/8" for bedrooms and 1/2" for bathrooms/laundry where heat/cool air flow is not as important.

If necessary trim the bottom of the jamb to achieve the desired gap. Keep in mind you may need to shift legs up or down to achieve a right angle, and or conform to door irregularities. If you have a transition from tile to floor where there is a height difference, notch jamb so it sits flush on the tile and subfloor.

Check if the hinge side of the door opening is plumb. If it's perfect you can nail the frame to the studs without shims, although I prefer not to do this because if you ever need to reset the door, it's much more difficult to remove if there are no shims. So if there is enough room, shim on both sides.

Be sure to check the level on the inside of the door opening and the face. (ie it could be vertical but leaning out toward the drywall, in which case the door will dip and could dig into floor.

When hinge side of door frame is in an shimmed and plumb (both angles), use shims to correct any bow in frame. 

Nail through shims and put door on hinges and check the gap between top of door and frame. Even though you're right angle may indicate it's a perfect 90, the door may not be square, which you'll see when the door is in the hinges.

You may need to shift the jamb (opposite the hinge) up or down a bit to get a consistent gap across the top of the door. A pry bar is useful for raising lowering. This is much, much easier if setting before the flooring since the jamb will get cut flush for flooring. If setting on finished floor you may need to cut the jamb or worse pull the door frame out and cut the jamb on hinge side.

Tip: you can fire a few finish nails through the door frame (no shims) to keep the door frame from falling out but still have flexibility to adjust it.

Check where the door hits the nosing. You may need to move the frame towards or away from the drywall to get it flush. Once you're satisfied, start shimming the non hinge side to get a consistent gap between door and frame (I aimed for about 1/8"). The non hinge side doesn't need to be exactly plumb -- it only needs to conform to how the door closes.

About 3 shims per side. Fire several nails through the shims for strength.

Working with my carpenter it took about 30-45 minutes per door, depending on how much finagling is required to get it all plumb. Closets took an hour or more, mostly because we had to wrestle with manufacturing irregularities of the doors (Orepac).

Door bottom may need to be cut if not level, or too low. Remember you can go up but not down without starting over.

If you screwed up, cut out the shims with reciprocating saw, remove nails or pound in, and start over

The closet doors are the most difficult since you have to get the doors to meet at the middle with a uniform gap and at the same height.

As you might expect hammering a shim on a top or bottom hinge will raise or lower the door

Tools:

6 foot level

Square

Nail gun

Trim saw (notch jamb, flush cut shims)

Reciprocating saw (cutting out old frame). Cutting out new frame if screwed up.

Awl to remove door pins

pry bar/chisel for removing carpet tacks, adjusting legs