Things You'll Need
1-3/4" thick door
1-3/8" thick door
6 standard hinges
2 internal deadbolts (one-way deadbolts)
2 exit locks with knob or lever trim
Connecting doors, also known as communicating doors, are often used between adjoining rooms in hotels or cruise ships. They allow families or groups to open both doors and pass between the two rooms. When the rooms are occupied by separate groups, the doors can be locked to maintain security and privacy. Installing connecting doors is as easy as installing a single door, but it is important to choose the correct doors and hardware for this application.
Install connecting doors in a standard hollow metal frame. The frame must be prepped to accommodate both doors, including hinge preps and lock strikes. Both sets of hinges should be placed on a single jamb, with both lock strikes on the opposite jamb. This type of prep is a standard option offered by most hollow metal frame manufacturers.
Choose your doors. In communicating frames, the doors should have slightly different thicknesses. This helps to control noise transmission between the two rooms. The industry standard for this application is for one door to measure 1-3/8" while the other door measures 1-3/4". One door should be righthand reverse, and the other should be lefthand reverse. This lets the door manufacturer know how the doors should be configured.
Specify door preps. If using steel doors, request that the manufacturer prep the doors to receive hinges, deadbolts and standard cylindrical locksets. If you are using wood doors, you can make these preps yourself if desired. The majority of wood doors will already have hinge preps, though you may need to add holes for the locks.
Install hinges on each door. Place the hinges on the edge of the door and fasten it in place with the screws provided.
Fasten the doors to the frame using the screws provided. Make sure that both doors will swing out away from the frame as you install them as it's easy to mix these doors up.
Remove the deadbolt locks from the package and tape the lock templates to each door. If there are no existing preps in your door, use a hole saw to cut the doors to receive these locks. The templates will indicate the size and location of these holes. You will also need to use your hole saw to cut a hole in the side of the doors for the bolt itself.
Insert both halves of the deadbolt lock into the holes you drilled. The thumbturn on the lock should face into the room while the other side of the lock will have a blank rose trim. Align the spindle or connecting rod on each half of the trim and fasten them together with screws from the inside of each room. Each door should have its own deadbolt.
Cut a second hole in the door to accommodate the exit lockset. An exit lock can be freely opened at all times but only has trim on one side of the door. The other side is covered by a blank plate. Cut a hole for this lock according to the template then connect the two sides of the lock. Fasten them together with screws installed from the inside of each room. The knob or lever on each lock should face into the room.
Add strike plates on the frame for both the deadbolt and the latch. Repeat this process on both sides of the opening, using the screws provided with each strike to secure it to the frame.
A standard hollow metal frame has unequal rabbets. This means that the spacing on either side of the door stop is uneven. Because of this, you will not be able to install two doors that are both 1-3/4" thick in a single frame unless the frame is custom built. If you must install two doors of the same size, make sure they are both 1-3/8".