Secret doors and secret rooms are a very special method of creating a personal room within your home. There are many ways to create these hideaways. Some are extremely complex, requiring hydraulic remote activated opening and even biometric security measures, but the classic method of a false wall-door or bookshelf door are timeless classic methods. So, we're going to focus on the simplest method of creating a secret door: The False-Wall Door. This typically works best in walls with paneling but can be adapted to work with basic drywall construction. Additionally, it can be adapted into many other types of secret doors, including the bookcase door.
I'm not going to address the installation of the wall that separates the rooms or the proper method of mounting drywall, but rather the installation of the door itself. If you're starting with building the dividing wall, you should include a frame for the door. There is no need to worry about building a special frame, a typical door frame will work for this. Of course, this means that you can convert any standard door frame into a secret door.
Step 1- Record the Dimensions of the Door Frame
This is probably the single most important step, as not all doors are set to specific dimensions, especially in older construction. Measure and record the height, width, and depth of the door frame, as well as the distance to, height, and width of your latch. These are crucial measurements that will determine the dimensions of the door. There is no way to accurately predict and plan the dimensions of any given door, so wait to purchase the materials required until after you record the dimensions. For this article, let's assume that the door frame has a 28-inch width, 80-inch height, and 4-inch depth.
Step 2- Get, Mark, and Cut Your Wood
After you have the dimensions for the door frame, acquire the wood necessary to build the door. You need 2 2x6s that are the same or slightly larger than the depth of your door frame. These are the top and bottom of the door, and will be 2 inches shorter than the actual door frame's width. In this case, we need 2 1x6x26-inch pieces. You also need 3 pieces of lumber the same height as your door frame, but the one that will go in the middle will be thicker to aid in supporting the drywall. The two 1x6s that provide the outside frame of the door should be only an inch less than the door frame's height, but the central 2x4 should be 3 inches shorter than the door frame's height. So now we have 2 1x6x79-inch pieces and the 2x4x77-inch piece.
Step 3- Assemble the Door's Frame
Once you've cut the wood to size you can assemble the door. Start by nailing the central support board (the 77-inch 2x4) to the center of the bottom board (one of the 26-inch 1x6s). You need to center this, so measure and find the center length and width of the bottom board. When nailing the boards together, put 2 nails on either side of this center point. Next nail the top board (the other26-inch 1x6) to the opposite end of the central support board.
Now attach the two remaining sides of the frame (the 79-inch 1x6s). Align the bottom of the outer board flush with the bottom board, creating a 90 degree angle. Nail this board into place with at least 2 or 3 nails. Repeat this for the opposite side of the door. If done correctly you should be left with a rectangle that is the same width as the door frame, an inch shorter than the door frame's height, and has a central support beam. You may want to dry assemble the door first before securing any of the pieces.
Step 4- Attach the Hinges
It is important to not to make mistakes when attaching the hinges, as it can degrade the integrity of the whole door. First, mark the area you want the hinges to be place and draw a general outline of the hinge. Use 3 heavy duty hinges spaced across the entire left side of the frame, as the finished door can be quite heavy. Next, chisel out the area for the hinges on the outer left side of the door frame. The depth of this area is dependent on the size of the hinge itself, but essentially one side of the hinge should fit securely into the wood without protruding above the surface.
Ensure that when you chisel the area for the hinge that you chisel to the outside of the wood so that the interlocking area of the hinge has room without blocking the door. If your existing door frame does not already have places for the hinges chiseled out you need to repeat this process on the door frame as well, just be sure that they line up with the door. You should dry fit each of the hinges in their areas to ensure that they fit correctly (do this on the frame as well). Finally, secure the hinges in place, ensuring that they are installed so the door opens inward.
Step 5- Mount the Wheel and Latch
For the door to work properly and open smoothly, it needs a latch that can be flush with the finished door, and a small wheel or caster to help support its weight and make it glide. First drill a hole in the bottom board about 2 inches away from where it meets the outer right board. This hole will be used to install the wheel, so its width is dependent on the type of wheel you're using. Some wheels secure with a nut and some snap in place, so follow the installation directions for the one you have. It should fit snuggly.
The simplest latch to use is a ball latch. One side has a ball set into the side of the door, held in place with a spring. When the close the door, the ball slots into the other side of the latch, set in the frame. The spring is strong enough to hold the ball in place and keep the door from opening, but a simple push and the door will swing open. Drill out the door and frame in matching spots and install the latch according to the directions on the packaging.
Step 6- Mount the Door
Get some help for this step. Stand the door up in the doorframe. It should fit securely, but if it doesn't, either sand down or plane the top of the door until it fits securely, leaving virtually no room between it and the doorframe. Screw the hinges into the designated areas of the doorframe. At this point the door should stand on its own, and be able to be opened and closed. The door should provide moderate resistance to being opened, allowing pressure to be applied without causing it to open. You can sand or plane down the top and outer right board to reduce the amount of force required to open the door to a suitable range for you. Ensure that once you've hung the door there is room left to install the drywall so that is doesn't protrude from the rest of the wall.
Step 7- Hide the Door
Hiding the door from sight can take a fair amount of skill and patience, and is entirely dependent on the location you chose to install the door. First, cut out a sheet of drywall to meet the exact dimensions of your door, leaving a 1/2-inch section between it and the floor. Install the drywall onto the door. Done properly there should only be a small outline of the door, with a 1/2-inch missing from the bottom.
Install your base molding at the bottom of the door, as you would with any other wall. This will cover the 1/2-inch gap. The final stages of hiding the door require a bit of creativity. If you've cut and filed the drywall perfectly the outline of the door should remain barely detectable, but otherwise you need to hide the outline.
Paneling - The best way is if the entire wall is covered in paneling. The outline of the door can be hidden in the joints in the paneling and the door will be almost undetectable.
Bookcase - A bookcase is a classic piece of camouflage, and you can use an existing one rather that starting from scratch. It has to be smaller than the door to allow it to pass through the doorway, and it needs hidden wheels on the bottom to help it move easily. Screw through the back of the bookcase into the frame of the secret door.
Posters - You can cover the seams with posters, pictures, wall mounted coat racks or the like.
Drywall Tape - An artful solution is to apply drywall seem tape around the outline in a similar fashion to covering typical drywall seams. This allows you to easily paint over the entirety of the door to match the room color as well. The tape needs to blend in with the hidden door, but not entirely attach to it.
If once you've hidden the outline you find it difficult to close the door, installing a coat hook in the center of the door (so that it attaches to the central support beam) will allow you to utilize it as a secret handle.