There are many factors that can influence you use a prehung door as a replacement door. They are a great option for individuals who do not have as much experience in home improvement. This is because these doors are easier to install, and several door installation steps have already been done for the customer. For instance, they usually come with a precut doorknob hole and hinges already attached. Although these doors are easier to install than slab doors, you still have to concentrate and follow many steps to correctly install a prehung door. Follow the steps below to ensure a level, snugly fitted prehung door.
Consider Other Factors
Check the height of the space where you intend to install the door. Consider whether or not the floor is level. Prehung doors come with extra long sides so that they can be cut down to the size needed. Measure the sides of the frame, and cut the sides of the door down to the needed size. If the floor is not level, this will not be a problem. All you need to do is cut each side of your prehung door a different length. This will allow the door to fit without a lot of work and without anything being crooked or ill fitted. The difference in the side length should be small enough to be invisible to the eye.
Place Shims Where Needed
Now, take the time to check to see if your rough opening is plumb or not. If it isn’t, just place some shims between the frame and rough opening. These will fill in the gaps to make simple installation possible. Have someone hold the door in place while another person inserts the shims on the hinge side of the door where needed. When the door is flush, tack it in place with some finish nails. Penetrate the frame, shims, and trimmer, but do not nail completely. You want to be able to remove these nails if necessary.
Place Door Into Opening
Push the hinge side jamb as tightly as possible against the shims and trimmers while placing the door into the rough opening. Check to see if this is plumb. If it is not, add shims where needed until the casing is plumb. Secure the door and remove the gaps between the wall and casing with shims.
Make Necessary Adjustments
The space between the head jamb and top of the door should be between 1/8 inches and 3/14 inches. The angles should also all be uniform. The reveal between the latch side jamb and door should be spaced about the thickness of a nickel. If an adjustment is necessary, just push the headcasing upward and tack it into place, through the casing and trimmer stud at the top corner on the latch side.
Anchor The Jamb
Now, it’s time to make sure that jamb does not move around. To anchor the jamb, you will need to place shims between the trimmer and the jamb on the latch side. You will place the pair of shims near the top of the door opening so that they are not adding pressure but are just touching the jamb. Nail this into place. Two more pairs of shims are needed. One pair is needed just a few inches above the jamb’s base, and another pair is needed just above the strike plate. These pairs of shims are to ensure that the jamb does not warp or move over time.
On the hinge, replace the middle screw with a longer one. You want to make sure that your new middle screw drives into the trimmer stud by a minimum of an inch.
Attach Split Jamb Or Trim
Now, you will attach the split jamb on the outside of the door. There will be a groove in the main jamb that allows you to push and tap that split jamb, which is essentially like the outside casing of your door, into place. The split jamb should be nailed to the wall along every 18 inches of the casing and each miter. Now nail the casing making sure you penetrate through the stop and into the trimmers. Also, secure the casing through the shims on the latch jamb right above and below the striker and also the shims close to the top and bottom.
Install Latch Hardware
Attach your strike plat to the latch jamb. Next, place the latch bolt into its place, and put the mortise onto the door’s outer edge. Next, place the doorknobs over the latch bolt before screwing the knobs together. Now, close the door to see if it will latch. If it does not, but you hear a rattle instead, adjust the prong on the strike plate until it catches. Then fully secure the hardware.
Ensure once again that the door is plumb, even, and level. Cover the exposed nail heads with putty, and smooth the putty down. Now, just paint the trim where necessary.
Prehung doors are a simple and easy option for the average person. It is definitely possible for you to install a door yourself, and it is easier than you ever imagined. Prehung doors come with so many steps already out of the way making it possible for a relatively inexperienced person to make repairs and improvements to the home. If you need a new interior door, try a prehung door. It only takes a few steps and a couple hours of your day.