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How to Install a Knox-Box

Debbie Tolle

A Knox-Box is primarily used for emergency access to public, residential or commercial buildings. The box, also known as a rapid entry system, allows emergency fire and medical personnel quick entry into the building without the use of damaging force. Keys are stored inside of the box, and a code is used to gain access to the keys. The Knox-Box is securely mounted to the building on a solid wall or beam to help deter would-be criminals. The instructions provided are for a surface mounted box.

  1. Use the stud finder to locate a stud on the interior side of the wall where the Knox-Box will be installed. Make a small pencil mark on the wall to indicate where the stud is. Locate a second stud if the box is at least 16 inches wide, and mark its location on the wall. Knox-Boxes are installed on the exterior side of a wall, but the bolts go through the box from the interior side.

  2. Measure to a height of six feet from the floor, and make a pencil mark in the same location as the stud or studs. This is the recommended height that a Knox-Box should be placed.

  3. Ask a helper to hold the box on the six foot mark with at least two bolt holes lined up on a stud. The bolt holes are in the back of the box. Place the level along side the box to make sure your Knox- Box will be level when you mount it to the wall. Mark each bolt hole location with a pencil and remove the box from the wall.

  4. Drill four 3/8-inch-diameter holes through the wall from the interior side. This will require a wood or metal drill bit at least six to eight inches long. The type of drill bit you use will be based on the type of studs that are in the wall. You will need to use a concrete drill bit to start the holes if the surface of the interior wall is masonry.

  5. Align the Knox-Box over the bolt holes on the exterior side of the wall. Ask your helper to place a steel washer on each bolt and then slide the bolts through the holes on the interior side of the wall. The bolts should go through the wall and into the back of the Knox-Box.

  6. Place a nut on each bolt and tighten it using an appropriate size socket and wrench. When the Knox-Box is secured to the wall it is time to call your local emergency services department so that the box can be locked.

  7. Caulk along the top and both sides of the box to prevent water from running down behind the box and possibly damaging the wall surface. Leave the bottom of the box uncaulked to allow any trapped moisture or condensate to escape.

  8. Tip

    You can use a steel plate the same diameter as the box if there are no studs in the location you want to install the box. Use a drill bit designed to drill through metal to drill holes through the steel plate. You can use the Knox-Box as a template for the location of the bolt holes. Place the steel plate on the interior side of the wall and slide the bolts through the plate. The steel plate will provide reinforcement for the box.


    Use caution when handling the Knox-Box during installation. The door can accidentally close and smash your fingers.