How To Install A New Door Jamb

Are you redecorating or remodeling your home? With tons of things to get done it can definitely be overwhelming. Usually one does not think of installing a new door jamb as part of the process, but in some instances you may need to do so. Read on to learn how to install a new door jamb and discover the installation process, prices and reinforcement as well.

Materials That You Will Need:

  • Safety Goggles
  • Circular Saw
  • Hammer
  • 2d & 8d nails
  • Electric Drill
  • Drill Bits
  • Carpenter’s Square
  • Door Stop Molding
  • Shims
  • Level
  • 36″ Header – Interior Door Jamb Piece
  • 84″ Side Legs – 2 Interior Door Jamb (2 Pieces)
  • Pencil
  • Work Table/Space

1.  Measure and Cut

  • Put on your safety goggles and measure the top width of the opening of the door.
  • Pencil in the measurement on one of the 84″ door jamb pieces.
  • With the carpenter’s square, place it on the marked measurement and mark it off by drawing a line for guidance.
  • With the circular saw, carefully cut the door jamb piece to that measurement
  • On each side measure the floor to the door opening and subtract 3/4 inch to compensate for the gap.
  • Pencil in the measurement of this on the other piece of the 84″ door jamb.
  • Carefully cut it with the circular saw.
  • Set aside the lumber.

2. Installation of Door Jamb

  • The shorter piece of lumber will need to lay out on a work table so that, with your drill, you can drill 4 holes through it. Now insert an 8d nail and tack it in without the nail going right through.
  • Using your level, level off the piece of lumber at the top of the door opening. You can use the shims to level it off by putting them between the lumber and the door opening.
  • Measure the width of the door and install the two pieces of door jamb on both sides of the door opening.
  • Be sure to use 8d nails because it needs to be 1/8″ bigger than the door itself. Level and install carefully.
  • Once again, measure 1 /8″ from the front edge of the door jamb and pencil in the measurement line. This front edge of the door is where the door will open into the room. Making a few different measurement marks by moving the tape measure up and down will help guide where the door is to open. Repeat this method for the overhead piece of lumber as well.

3. Secure

  • You need to measure the space from the top between the two door jambs and then cut a piece of door stop material the same length.
  • Secure to the top of the door jamb based on the marks that you made prior and use 2d nails, making sure that the flat side faces the door.


  • The price to install a door jamb varies based on the size and materials used. If there is one opening then it could range from $140-$230. Having the right tools for this on hand will save you money, but if you don’t  have them you may have to borrow, rent or buy so make sure to factor in a flexible budget.

Now that you have discovered how to install a new door jamb, the results are very rewarding. You have just accomplished yet another task on your newly remodeled home. Now it’s time to move on to the next project! If you would like some help with installing a new door jamb, Home Painters Toronto would love to help finish off that door jamb with some paint or stain for you! 

Call us NOW at 416-494-9095 or email brian@homepainterstoronto.com!

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