How To Prep a Door for Standard Door Hardware

If you're installing a door knob or lever with a deadbolt above, understanding standard door prep is really important. Door prep is the process of creating the holes in a door where you'll install hardware like a knob, lever, handleset, or deadbolt. Specifically, we're talking about standard door prep, which is the most common and straightforward method.

What is Standard Door Prep?

While there are different ways to prep a door, standard prep is the easiest to work with, especially when you need to find replacement parts. If you buy a door from a store like Home Depot, it will typically come with standard prep already done. However, if your door doesn’t already have standard prep done, here's how to prep a standard door:

Step 1: Gather Your Materials

• Template: You can buy one or make your own. The template will keep your whole saw or drill bit in the right place and at the right angle. You can purchase a template from hardware stores, but generally, they will only allow you to do one bore hole at a time. If you need two bore holes for a door handle and keyed deadbolt above, you may just want to build your own template to get the holes spaced just right.
• 3/4" plywood: You'll need this for the template and U-shaped guide.
• Drill with 2 1/8" and 1" hole saws.
• C-clamps or woodworking clamps.
• Measuring tape and pencil.

Step 2: Create Your Template (skip this step if you bought a template)

1. Cut the Plywood: Start with a piece of 3/4" plywood that's 18" tall and 8" wide.
2. Measure and Mark: Measure 3/4" from one edge and draw a vertical line. This will be your starting point.
3. Mark the Bore Hole Centers:
   o Measure for the backset (either 2 3/8" or 2 3/4") from the edge of the plywood and mark it.
   o From this mark, measure up 5 1/2" and mark the center for the second bore hole.
4. Drill the Bore Holes: Use a 2 1/8" hole saw to drill out both bore holes on the template.

Tip: If you place the center of the bottom bore hole exactly 6" from the bottom of the template, it will align perfectly when you start on the door.

Step 3: Continue Building Template

1. Cut the Door-Width Strip:
   o Measure the thickness of your door (usually 1 3/8" for interior and 1 3/4" for exterior doors).
   o Cut a strip of 3/4" plywood to match the door thickness and make it 18" tall.
2. Mark the Cross Bore Locations: Line up the template with this strip and mark where the 1" cross bores should go. These will be centered on the door’s thickness.
3. Assemble the Guide:
   o Attach the two side pieces (the drilled plywood pieces) to the door-width strip with screws, forming a U shape.

Step 4: Position the Template on the Door

1. Measure Up: From the bottom of the door, measure up 36" and mark the spot. This is where the center of the bottom bore hole should go.
2. Align the Template: If you followed the 6" tip, place the bottom of the template at 30" from the door bottom. This gets you perfect alignment.
3. Secure the Template: Use C-clamps or woodworking clamps to firmly attach the template to the door, ensuring there’s no gap at the top or bottom.

Step 5: Drill the Bore Holes

1. Drill Partway Through: Start drilling the 2 1/8" bore holes from one side of the door, stopping halfway through.
2. Drill from the Other Side: Switch to the opposite side of the door and drill the holes to avoid blowout.
   o Optional: Use masking tape around the drilling area to minimize splintering, though the template should help with this.

Step 6: Drill the Cross Bores

1. Use the Template: With the template still secured, drill the 1" cross bores in line with the bore holes.
2. Clean Up: Sweep away sawdust to avoid any mess.

Step 7: Final Steps

1. Remove the Template: Once you've drilled all necessary holes, remove the template.
2. Prep the Latch Areas: Your door is now ready for drive-in latches. You can also chisel out space for square-corner latch faceplates.

Standard Door Prep for Different Door Latches

Not all doors require the standard door prep for both the knob/lever and deadbolt. Here are a few other examples:

1. Drive-In Latches
   Drive-in latches are the easiest type to install. A door prepared for a drive-in latch will have a single 1" cross bore on its edge, as shown in the image. To install the latch, just slide it into the cross bore and gently tap it into place with a mallet or hammer. The latch features a ribbed collar around the top, which grips the door securely as it's driven in.
   
   
   
2. Rounded Corner Faceplate Latches
   These latches are used frequently and offer a polished appearance and a secure fit for the latch. These faceplates typically measure 2 1/4" in height and 1" in width, with approximately a 1/8" radius on the corners. Many door shops use a router jig to prep the door for these faceplates, making installation a breeze. But if your door isn’t prepped for rounded corners and you’d rather have a faceplate, think about choosing locks with square corner faceplates instead. It's a lot easier to chisel out square corners than rounded ones.
   
   
   
   
3. Square Corner Faceplate Latches
   Square corner faceplates are the same size as the rounded ones but have sharp, square corners. If your door is prepped for drive-in latches but you prefer faceplates, you can easily modify the door using a 1" chisel. Just mark a 1" wide by 2 1/4" tall area centered on the cross bore and chisel out about 1/8" of material. Square corner faceplates give you a clean, refined look. If your door is already prepped for rounded corner faceplates but you prefer square, just chisel out the corners—it's a quick and easy task.
   
   

Contact Direct Door Hardware with Door Prep Questions

With your door now prepped for standard measurements, you can install most locks from major hardware brands without any issues. If you need a refresher or more basic help, check out our answers to find out What Is Standard Door Preparation? If you have any issues with your standard door prep, feel free to leave a comment or give us a call. Our experts are always happy to help!