How to Install Your Exterior Door

Posted by SBMTX on Apr 4th 2023

How to Install Your Exterior Door

You've chosen a beautiful exterior door that is perfect for your home. Now comes a choice: do you install the door yourself or pay an expert to come out? Hanging a door doesn't have to be a professional job, especially if you're on a tight renovation budget. With our step-by-step guide, we'll help you turn a pre-hung door into a beautiful entry to your home.

Before You Buy

Before you can install your pre-hung door, you need to select the right door. You'll want to determine two things for your door: the measurements and the handedness of the door.

Measuring Your Door

If you're replacing an existing door, it's best to match the existing door and frame size. Measure the door and frame by,

●Measuring vertically from the floor to the top of the doorjamb

●Measure the width of the doorway in three places, top, middle, and bottom (you'll use the shortest length)

●Determine the width of the door jamb by measuring from the front edge of the door frame to the back edge of the door frame.

Determine Handedness

You'll next need to determine the handedness you need for your door. Stand in the doorframe with your back to the hinges. Whichever hand (left or right) is closest is the handedness of the door. Remember that you'll want your exterior door to swing inward. Keep that in mind as well as which side you want your doorknob to be on.

Remove the Old Entry Door

Once you're ready to install your new door, remove your old door and trim the opening. Check for any damage or rot. If you have damage, you'll need to repair this before installing your new iron or wood door.

Installing Your New Pre-Hung Door

Now that the old door has been removed and you have ensured there's no damage, it's time to install your new entry door. Whether you're installing an iron or a wood door, it's a good idea to have a second person assist you, as both are heavy doors. To install your pre-hung door,

  1. First, measure the new rough opening of the doorway and compare that to the measurements for the pre-hung door to make sure it fits. When you remove your door from the packaging, leave the retaining brackets in place to keep the door in a closed position during installation.
  2. Center and test fit the door in the rough opening.
    1. Use a level to ensure the door is plumb (insert shims, if necessary, under the lower side jamb until the door is plumb).
    2. Make sure the door is centered in the opening.
    3. Adjust as necessary to keep the door jambs square with each other.
  3. Trace an outline of the molding while you have the door in place (enlarge the outline if you have vinyl or metal siding to give you room for extra trim), then remove the door and frame.
  4. Cut along the outline you make of the molding down to the sheathing.
    1. Use a sharp wood chisel in the corners instead of the blade cutter to avoid damaging the siding.
    2. Start the cut clear of the siding and lower the moving blade into it.
  5. Apply building paper to exposed areas of the wall and door frame to provide a moisture barrier.
  6. Cut your drip edge to fit the width of the opening.
    1. Slide your drip edge under the siding at the top of the opening (do not nail the drip edge)
  7. Check your door fit again to ensure that the opening is still large enough for the door.
    1. If necessary, widen the opening.
  8. Remove the door again when you're satisfied with its fit.
  9. Apply several beads of silicone caulk to the bottom of the door.
  10. Center your door and frame in the opening, and push the molding tight against the sheathing.
  11. Check the door jamb on the hinge side to ensure it is plumb (shim if necessary)
    1. Temporarily screw the hinge jamb into place.
    2. Check once more that it is plumb, and loosen the screws.
  12. Use another entrance to enter and check the inside of the door. Use shims to stabilize the jamb by inserting them into gaps.
  13. If your hinges are not already installed in the door, install your hinges.
  14. Remove the retaining brackets.
  15. Install your anchor screws by removing two of the screws on the top hinge and replacing them with long anchor screws (if you have side lights, don't use screws longer than what the manufacturer calls for)
  16. Use 10d galvanized nails every 12 inches to anchor the molding into place.
    1. Use a nail set to drive nails below the surface of the wood.
  17. Apply caulk and insulate the entire door frame.
    1. Fill in nail holes with caulk and apply weather stripping.
  18. Use a utility knife to cut shims flush with the framing and install a new casing to repair any trim damaged during installation.
  19. Install the new lock and knob.

While installing your own pre-hung door is a complex job, it is one you can do yourself with patience, know-how, and tools.

Are You Looking for a Pre-hung Door?

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