How to Install a Flush Door Bolt

mortise deadbolt
What You'll Need
Flush bolts
Hole Saw

A flush door bolt is a particular type of door bolt that is installed in a way that it is even with the door side. When considering installing a flush door bolt, take note that there are two types to choose from – manual and automatic. Manual flush door bolts require someone to lock and unlock it. The automatic version will open automatically when opening the door and closes when the door is closed. When installing a flush door bolt, one is to be positioned at the top of the door, and one at the bottom. The middle can be installed with a dead bolt. Below are instructions on flush door bolt installation.

Step 1 - Determine the Position of the Bolts

Determine where to install the flush bolts on the door. A recommendation is to install them two feet above the center of the door and two feet below the center of the door. The bolts should come with a template to be used as an installation guide. Use the template to mark the required holes on the door and the doorjamb.

Step 2 - Cut Holes

Using the template provided by the manufacturer, determine where to cut the holes on the door and the door jamb. Before cutting, make sure to mark the exact locations of the holes. Be sure the hole on the door jamb corresponds to the hole on the door.

Start either with the door jamb or the door itself. Use a hole saw to drill a hole in the door or use a hammer and chisel. For the door jamb, chisel out a thin portion that will accommodate the entire base plate. Afterwards, drill a hole at the recommended depth, enough to allow the tenon or the bolt to enter through.

Take note to read the instructions on the bolts first before proceeding with any cutting procedure. It is also important to follow direct instructions on the template in order to provide the bolts with the correct holes. When cutting with a chisel, cut across the grain.

Step 3 - Install the Entire Bolt


Start by securing the base plate onto door jamb. Before inserting the base plate, drill holes for the screws first. Place the base plate firmly on the mortised hole and tighten the screws. Afterwards, press the entire flush door bolt into the hole cut on the door. When the bolt is positioned into place, it should rest evenly on the door. If not, chisel out the hole until the bolt can be properly fitted. Mark where the screws will be inserted and drill holes into them. Position the flush bolt onto the door and tighten the screws.

Follow the same procedures when installing the other flush bolt. When both bolts are installed, test them by closing the door and locking the bolts tight; if the bolts lock easily, then the installation is complete.