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How to Reinforce Door With Knob Reinforcer

Updated: Sep. 02, 2021

Wrap-around metal plates strengthen exterior doors against break-ins.

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This story walks you through the how to steps to install a doorknob reinforcer, aka, door wrap around plate, on your exterior doors. It's a simple, inexpensive project that makes your entry door more secure and less vulnerable to break-ins.

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An hour or less
Less than $20

Install the doorknob reinforcer

Photo 1: Take measurements to determine the reinforcer size

Measure the “backset,” the distance between the door edge and the center of the door knob; the thickness of the door; and the knob hole diameter. Buy a reinforcer that fits all those measurements.

Photo 2: Take off the door knobs

Unscrew the two screws on the inside knob and remove both knobs. Also remove the two 3/4-in. latch screws, but leave the latch in place.

Photo 3: Reinstall the doorknobs over the reinforcer

Slide the three-sided reinforcer plate onto the door. Secure it to the latch with the two 1-1/2 in. screws provided and remount the doorknobs.

Photo 4: Screw the reinforcer in place

Drill four 3/32-in. pilot holes and install the corner screws on the interior and exterior sides of the reinforcer plate.

Install a door reinforcer or a door wrap around plate on your entry and garage service doors to help discourage break-ins.

Reinforcers or door wrap around plates are three-sided metal plates that encase and strengthen the door around the latch, which is a door’s most vulnerable area. The reinforcer shown is meant to strengthen door latches (Photo 3), but you can also buy reinforcers that strengthen deadbolts. Install door wrap around plates on fiberglass, wood or steel doors as shown in Photos 1 – 4.

A reinforcer extends the door edge about 1/32 in., and so may rub the door frame of tight-fitting doors. If so, slightly deepen the hinge mortises with a chisel to widen the gap at the latch side. Or chisel a 1/32-in. recess into the door edge so the reinforcer fits flush. Door reinforcers are found at home centers and well-stocked hardware stores. Check out these 22 cheap ways to theft-proof your home as well.

Required Tools for this Door Wrap Around Plate Project

Have the necessary tools for this door wrap around plate DIY project lined up before you start—you’ll save time and frustration.

  • 4-in-1 screwdriver
  • Cordless drill
  • Drill bit set
  • Tape measure
The drill bit you’ll need is a 3/32 in. bit. Any drill or flathead screwdriver will work if you don’t have a cordless drill or 4 in 1 screwdriver.

Required Materials for this Door Wrap Around Plate Project

Avoid last-minute shopping trips by having all your materials ready ahead of time. Here’s a list.

  • Doorknob reinforcer