Sign In to join the community | Help
Install & Replace

Installation of a Split Jamb Prehung Door

Well, I had someone who was going to do this after he finished framing a closet in my upstairs bonus room, but he left without doing it and now I have this door sitting up stairs still packaged.  I have had the bonus room drywall and finished and even painted the inside of my closet and have hung wire shelving in it as well.  But still don't have my door installed.  I am going to try to do it myself and was looking for any type of instruction.  I am not even sure it is the right size, because when I took the measurement of the gap of the door *still packaged* it doesn't measure out with the frame and drywall of my door.  There is still a 2x4 piece at the bottom of my floor as well and I am unsure if I have to cut that out or not.  I attempted to look up "how to's" online but I don't ever get a good enough example that I feel comfortable enough to follow as a guide.  Please help.

Not what you were looking for ? Try posting a question
Posted 2010-12-28T00:57:38+0000  by ugagirl8 ugagirl8

While I am not a Home Depot rep, I might be able to help a little.  Plan on spending a little time with this, depending on your skills.  Take your time, do not rush.


Tools you will need: 

  • Tape measure
  • Hammer
  • Nail Set
  • Reciprocating saw or hack saw
  • Screw driver
  • Drill (can also be used instead of screw driver with proper attachments).
  • Level - recommend 2 foot or longer.


The door frame dimensions should be smaller than the rough opening for your closet by about 1"-2".  Any more and it will need filler pieces to be able to solidly mount.  If the new door frame is wider than the rough opening, it won't fit.  When measuring height, do not count the 2x4 on the floor.


As to the 2x4 on the floor of the rough opening, it was probably just there to keep the framing intact before the wall was lifted and put in place.  A lot of professional framers do this during construction to save time and keep the rough opening square until the wall is upright and secured.  As long as it doesn't have anything holding it down within the opening, you should be able to cut it out flush with the rough opening sides using a hack saw or reciprocating saw.


Now, assuming the 2x4 can be easily removed and the rough opening is bigger than the framed door, you can proceed.  Unwrap the door and set it in the rough opening with the doors swinging in the direction you wish to open them in.  The gap on either side should be as close to equal as possible.  The gap at the top should be no greater than 1".  Lift the door if necessary, as carpet can fill the bottom gap.  Use shims to temporarily hold the door frame up if needed.  Once placed, insert shims from both front and back equally.  You should have a pair of shims at each hinge.  Use a level to ensure the door frame doesn't get out of alignment.  and measure top and bottom widths to make sure the frame stays square.  The frame should be flush with the wall on the outside and inside of the closet.  If the frame is slightly wider, make sure it is flush on the outside (easier to mask and less noticeable).



Once the frame is solidly shimmed you can secure the door frame in place.  I recommend using a couple of 3" deck screws.  Remove 2 screws from each hinge and replace them with the deck screws.  This way, the weight of the door is additionally supported through to the studs and doesn't require hiding any framing nail heads.  You should also use finishing  nails, but not as many are needed and they can be nailed in close to the door jam where they will be less visible.  They should also go through the shims to keep the frame from warping.


Shim the top of the frame only enough to keep the frame from moving up.  Drive a finishing nail through the frame into the shims and use a nail set to hammer it just below the surface of the frame, so it can be filled in with wood putty and/or paint.


Once the frame is secure and everything looks solid, test the doors for proper swing and to ensure they don't bind.  If everything looks good, cut the shims flush using a utility knife.  Make a deep slice flush with the frame without damaging the frame.  Don't try to cut through.  Once the cut has been made, you can snap off the shim in the opposite direction of the cut.  Now you can install the door trim, do any touch up painting, and your finished.



Posted 2010-12-28T17:42:39+0000  by GrueMaster

Hello Ugagirl8, and welcome to the Home Depot Community!

Installing a pre-hung door is usually a fairly simple and straightforward task.  Normally you would create a rough opening for a standard door size, buy and install the door, and then finish up the trim and walls.  In your case this order seems reversed.


First, we need to resolve the “measurement” issue. 

The 2x4 piece on the floor cannot be above floor level.  If it is then you will need to cut it out.  A handsaw or a reciprocating saw (sawzall) will quickly accomplish this.


Next, measure the rough opening width, height and depth, (stud to stud - remove any trim from the doorway), in 2 different spots and write down the smallest of each.  Measure the door with its frame (or in your case, take the dimensions off the label).  If your opening for the door is smaller than the pre-hung unit, then either you need to get a different door or change the opening size.  If the opening is too large, then you can reduce its size by adding wood to the studs as filler.


Please let me know what these measurements are.  Also, pictures would be helpful.


Once we have a compatible set of door and rough opening, then it’s time to install the new door.

On our website, there is an excellent project guide and a video on installing a split-jamb door.  You can find it here.

This is also a pretty good video on how to install a conventional pre-hung door.

In the video, the installer uses a power nailer, but you don’t have to.  In fact, when you first set the door and frame in the opening, it’s better to tack that first nail in by hand only partway since it’s likely coming back out anyway.  Use shims at the hinges, near the latch and anywhere else you need to make the frame plumb and square.  Don’t fully sink the nails until you have both sides and the top where you want it.  With a split jamb door, you simply attach the door side jamb first, and then install the split side.  You will need shims, 6d or 8d finish nails, level, square, hammer and a nail set.  The nail set allows you to sink the nails below the wood surface).


GoToGregg posted a video on building a door frame which may be helpful for you to see how the parts are assembled.


Once the door is in, then use 4d finish nails to install the trim boards.  You can buy these as a “door kit” or purchase the trim of your choice by the foot and cut it to length.


I hope this helps.  Let me know what the measurements are, and we can go from there.






Posted 2010-12-28T18:02:09+0000  by Chris_HD_CHI

Guy if im not mistaken she said it was a split jamb.....if it ineed is, this will be a different creature than a prehung door.....split jambs come preassembled with inside one peice (casing attached) and outside preassembled (casing attached) which case it sandwiches the opening.........But these are usually reserved for commercial applications.

Posted 2011-01-05T16:54:04+0000  by mahargbk
Not what you were looking for ? Try posting a question