How To Install a Pre-Hung Exterior Door
A quality front door makes a positive first impression on guests. A
weathered and worn door can compromise your family's safety and
security. Fortunately, you can install a new pre-hung exterior door with the
following instructions, and the related video, at Lowes.com/Videos.
GETTING STARTED
A pre-hung door comes already mounted to a new doorframe. The hinges are
installed and the lockset and deadbolt holes are pre-bored for standard installations.
Before removing the old door, it is a good idea to have the new one on hand.
Check it for damage and make sure it will fit. Here’s what you’ll need to do before
you purchase a new door.
01 Remove the interior trim around the existing door.
02 Measure the height, width, and depth of the
door opening.
The new door should be ½” less than the
height of the rough opening and ¾” less
in width.
03 Determine which way the door opens.
Stand with your back to the hinges and note
whether you would open the door with your
right or left hand.
04 Select the type of door you will install: wood, fiberglass or steel.
Fiberglass and steel doors are more weather-resistant than wood doors.
05 Give this information to a Lowe's associate, who can help you select the
appropriate door for your home.
06 When you get the new door home, read the manufacturer’s instructions.
They should provide you with information regarding the removal of the
factory-installed shipping braces or clips.
Some braces and clips keep the doorframe square during installation.
They will also help to clarify terms and identify parts.
REMOVING THE EXISTING DOOR AND FRAME
01Carefully remove the existing door's exterior trim for re-installation on the new doorframe.
Some doorframes come with the exterior trim pre-attached so you can discard the old trim.
Also remove insulation surrounding the doorframe.
02 Use a hammer and nail set, or screwdriver, to remove the hinge pins and detach the
existing door from the hinges.
For most hinges, insert the nail set in the hole at the bottom of the hinge pin and strike
it upward with the hammer. Keep driving the pin upward until it comes out.
03 Once the door is off the frame, remove the hinges from the doorframe.
04 Remove the screws, or nails, that attach the sill and jamb to the house frame.
If necessary, cut the nails off between the jamb or sill and the house frame with a
reciprocating saw. Wear safety glasses and be careful not to damage the house
frame studs.
05 If possible, remove the small pieces of wood, called shims, from between the
doorjamb and house frame.
06 Remove the old doorframe from the house frame.
You may need to use a pry bar under the sill.
INSTALLING THE NEW PRE-HUNG DOOR
01 Dry-fit the new door in position to make sure it fits.
TIP: You may need help from a friend to lift the door in place.
02 Inspect the subsill (where the door will sit) to verify that it is square and level.
Adjust the subsill as needed with shims following the door manufacturer's instructions.
Also, check that the rough opening is square and plumb. If you’re not sure if your
rough opening is square and plumb, call a professional for assistance.
TIP: Thoroughly inspect the house frame for dry rot and pest damage and make needed repairs before proceeding.
03 Make sure the new door will clear the finished floor.
1. Measure the new door from the bottom of its sill to the bottom of the door.
2. Then measure the height of the existing interior flooring to ensure that the opening door will not hit the flooring.
3. If the new door won't clear, raise entire the doorframe with a piece of treated wood secured to the subfloor with caulk
and screws.
04 Weatherproof the subsill by applying a bead of caulk about 1" from the front and
1" from the rear of the rough opening, with a wave, or zig-zag, pattern in between.
Apply caulk to the underside of the doorsill, too.
05 Working from outside the house, set the bottom of the door against the opening,
then raise the frame into place.
TIP: You may need help from a friend to lift the door in place.
06 Temporarily insert new shims near the top of the frame to hold the door.
07 With shims, adjust the doorframe so that it is plumb and square in the opening.
Insert shims between the doorframe and studs at the hinge locations.
Shims keep the door level, plumb and square in the rough opening.
Be sure to have at least 1/8” of clearance between the jamb and rough frame.
08 Drive screws through the hinges and shims.
Some manufacturers recommend inserting the screws below the shims. Check your
manufacturer’s instructions.
09 On the lock side of the door, place shims near the top and bottom of the jamb.
10 Drive screws through the jamb and shims.
11 Check that there is even spacing around the doorjamb.
From inside, make sure there is even spacing at the door reveal.
From outside, check that there is a 3/8" to 1/2" space between the door and the
jamb stop at the top, middle, and bottom.
Make any necessary adjustments to the doorframe.
12 Insert additional shims around the frame following the door manufacturer's instructions.
For added strength, place shims at the lockset and deadbolt positions.
13 Remove any remaining shipping braces.
14 Open and close the door, checking that it swings smoothly.
Make any necessary adjustments.
Some pre-hung doors have an adjustable sill. Check your manufacturer’s instructions
for more information.
15 Drive screws through any additional shims to secure the doorframe.
16 Score the shims with a utility knife, then snap off the excess.
17 Secure the sill following the manufacturer’s instructions.
18 Apply minimal expanding spray foam insulation in the gaps around the frame
and allow to dry.
WARNING: Be careful not to get the foam insulation on your skin.
Rubber gloves are handy for this step.
19 After the foam has dried, trim any excess with a putty knife.
20 Reattach the door trim.
22 If the door is not pre-finished, apply a coat of paint or stain as recommended by the door manufacturer.
Remove the door from the hinges and work on sawhorses.
Check the manufacturer’s instructions for painting or staining the bottom of the door.
Don’t forget to paint or stain the trim, if needed.
A new door adds safety and security to your home, as well as its curb appeal. Be sure to check out the other videos and
instruction sheets on installing a lockset, deadbolt, and door viewer at Lowes.com/Videos.