Live from Los Angeles, California; it’s the Doors! Jim Morrison may be long dead but the doors are here to stay. No matter where you walk around your home’s interior, there’s probably an interior door to enclose an interior space. Closets, bathrooms and bedrooms almost exclusively use a 2-3 hinged style prehung door to keep areas secure when you’re doing the stuff you don’t want other people to see (or smell) you do. Installing a prehung door is a snap, so whether you want to replace your old doors or you’re starting from scratch with a new home or room addition, you can use these five simple steps to get your door hung right—without the job looking like Mr. Magoo did the work.
1. Measuring the Door
This is a confusing task—but only if you don’t know the secret trick. Measure the door opening at the top, center and bottom. It should be an even measurement like 30”, 32”, 34” etc. If it’s not, you might want to consider making the opening smaller to make a more common prehung door fit snug. Now take your doors rough opening measurement and subtract two inches. That new measurement is the size of the prehung door you need to buy. Big secret, huh? That’s why us contractors make the big bucks.
2. Choosing the Correct Swing
You also need to know which way the door will swing open; left or right handed. This can be a little confusing, but use this trick to figure it out. Stand with your back to the inswing of the door. If the door opens all the way to the left then it’s a left hand swing door, if it opens all the way to the right, it’s a-you guessed it, right hand swing door.
3. Prepping the Door
Prehung doors usually come with some sort of useless cardboard box covering that is designed to protect the door from nothing and to annoy the installer to their wits end. Remove the covering carefully and expose the door. In most cases, the door is held in place by staples along the inside of the two pieces of door trim. It can also be held closed with a plastic door latch inside of the door handle and striker cutout. You’re going to need a pair of pliers and a bible so you can get the staples out and pray they don’t break when you do it. The factory guys who put these staples in are stoners and should be drug tested immediately.
4. Separating the Door
It’s not called a split jamb door for nothing. Prehung (or split jamb) doors come apart so that each side of the trim sandwiches the drywall between the two, leaving a seamless installation, ready to go with minimal effort. Pull the door apart while it’s lying flat on the ground and set the trim portion aside. Pick up the door and the jamb section carefully and walk it into the area you are ready to install it, ensuring the hinges are on the correct side before you put it in place.
5. Installing the Door
Using a level and check the 2×4 stud opening for plumb. You may need to make adjustments to the 2×4 by adding wood shims to get the stud plumb for the door frame. Set the hinge side of the split door frame flush and tight to the subfloor, carpet, tile or other flooring material. Stick a finish nail in the bottom of the jamb’s trim. Now you can level the frame. Insert finish nails every 12 inches or so from the bottom of the trim to the top, ensuring the door is plumb as you insert each nail.
Next, close the door and adjust the opposite side of the trim so that the reveal (the gap between the door and the frame) remains consistent all the way around the jamb, and then nail the trim into place through the drywall and into the 2×4 stud.
Finish the job by slipping in the other split jamb trim piece onto the opposite side of the door opening. Close the door and adjust the trim so that the reveal remains the same around the opening before you nail it in place. Once complete (and, assuming it’s your own home) go ahead and do something secret and enjoy the beautiful privacy your new door provides!