How to Build a Hidden Door

Skill

ModerateCut and measure carefully for a seamless installation.

Cost

$263

Estimated Time

2 days

Part access door, part architectural detail, this clever embellishment can be used to disguise anything from a powder room to a servant’s staircase. So when This Old House general contractor Tom Silva set out to conceal the landing to homeowner Angela Daigle’s basement on the current season of TOH TV, the project seemed a perfect choice for her 1850 brick rowhouse. Tom used butler-door hardware and chamfered notches to make a swinging door that disappears seamlessly into its surroundings when it’s closed. Follow along as he walks you through the mechanics—and the magic—of creating your own hidden gem.

Similar to shown: Masonite Smooth Flush Hardwood Solid Core Interior Slab Door, about $65; homedepot.com. Heavy Duty Swinging Door Hardware, about $95; houseofantiquehardware.com

Step 1

Overview for How to Install a Secret Swinging Door

Saturday Hang the door and chamfer the stiles (Steps 2–11).
Sunday Finish the paneling (Steps 12–18).

Cut List

Scroll down the page for the list of tools and materials needed for this project.

Download the cultist for How to install a secret swinging door

½x8 poplar side stiles. Cut to fit.
½x6 poplar baseboards. Cut to fit.
½x4 poplar rails and center stile. Cut to fit.

If you’re building this project in an existing doorway, you’ll first need to deal with any door stops to allow the door to swing in both directions. To remove stops on a site-built jamb, score along each stop with a utility knife and use a pry bar to remove it. Stops on factory-made jambs aren’t easily removed, so instead use ½-inch-thick furring strips to pad out the jamb on either side of the stop, then simply buy a narrower door to fit. Either way, make sure to fill any gaps or cracks with wood filler and sand the jamb smooth before beginning the project.

Step 2

Install the Pin Hardware

Remove any door stops to allow the door to swing in both directions. Trace the pin socket on the head jamb, making these adjustments to the hardware instructions: Inset it an extra ½ inch from the side jamb, to keep the door rails from binding, and recess it only half the thickness of your door, to bring the face of the door flush with the jamb. Use a Forstner bit to drill overlapping holes, and press the socket in place. Check its location, as shown, and secure it with 1-inch wood screws. Install the pin on the door. The socket placement will move your door over by ½ inch, so you may need to rip it down to get it to fit in the jamb.

Step 3

Attach the Spring

Trace an outline for the spring hardware on the bottom corner of the door and use a jigsaw to cut out a notch. Screw the hardware in place. Drop a plumb bob from the pin hole in the socket and mark the floor. Position the door, slipping the pin into the socket and centering the spring hardware on the mark. Prop the door open, use a level to check for plumb, and screw the spring hardware to the floor with 1-inch wood screws.

Step 4

Install the Corner Baseboards

Measure from the adjacent baseboard to the edge of the door. Cut a piece of baseboard to that length, making a 45 degree miter cut along the end covering the wide gap between the door and jamb. The miter faces the gap. Apply wood glue to the back of the piece and tack it in place, as shown, with a pneumatic brad gun and 18-gauge brads. Do the same at the opposite side of the door.

Step 5

Mark the Baseboard for the Hardware

Measure between the two installed pieces of baseboard, and use the miter saw to cut the piece to fit across the bottom of the door, with straight cuts at each end. The spring hardware stands proud of the door, so you’ll need to make a recess in the back of the board; to mark it, hold the baseboard in place and tap it with a hammer, creating an impression on the back.

Step 6

Rout and Fasten the Baseboard

Trace the outline for the recess and clamp the baseboard to your work surface, facedown. With a ¼-inch straight bit in your router, set the depth to ¼ inch and rout the outline for the recess, then rout out the waste material inside it. (You can also use a sharp 1-inch chisel and a mallet instead of a router.) Fit the baseboard against your door, making sure it sits flat against the door with its top edge aligned with its neighbors, then glue and tack it in place.

Step 7

Cut the Side Stiles and Notch the Base Cap

To allow the side stiles to butt against the baseboard, you’ll need to notch the base cap molding on the adjacent walls using a sharp chisel or an oscillating multitool fitted with a flush-cutting blade. Hold a ½× scrap against the door wall, and use it as a guide to make the cut, as shown. Now, measure from the top edge of your baseboard to the ceiling, and cut the stiles to length.

Step 8

Scribe the Stiles

Mark the head jamb where one side stile should cross it—concealing the gap but allowing the door to swing freely. Here, the stile dies into the abutting wall, so it must be scribed to fit. Take a board that’s wider than necessary, plumb it against the wall, and make a second mark on the head jamb along its edge. Set the legs of a compass to the space between the two marks. Re-plumb the board, and use the compass to scribe the wall-side edge, as shown. Cut along the line with a jigsaw or circular saw, creating the correct contour and width in one go. Make the opposite-side stile the same way.

TOH Pro Tip: Tip Set the saw blade at a 5 degree bevel to undercut the scribed edge, making it easier to sand down any high spots along the cut.

Step 9

Mark for the Rails

Use a level as a straightedge to trace the pattern for paneling onto the door and wall. This design calls for a center stile and four sets of intersecting rails. To allow the ends of the door rails to clear the side stiles, you’ll chamfer a 45 degree notch into the edge of each stile where the rails meet it. Dry-fit a stile alongside the door, hold a scrap of ½×4 in place, and mark the edge of the stile, as shown. Mark the opposite stile the same way.

Step 10

Rout the Edge

Clamp a marked stile to a work surface, facedown, with its edge flush with the table’s edge. Fit your router with a 45 degree piloted chamfer bit. Adjust the depth so that the bit stops just shy of cutting through the face of the stile. Rout the chamfered notch between each set of marks. Chamfer the second stile the same way.

Step 11

Clean the Cut

Use a 1-inch wood chisel to clean up the notches, removing the material in the corners that the router bit can’t reach, as shown. Use a wood file to finish the notches.

Step 12

Attach the Side Stiles

Run a bead of wood glue along the edge of the left-hand doorjamb and on the back of the stile. Press the stile into place, concealing the gap at the jamb, and tack it down, as shown. Install the opposite stile. Next, hold the center stile board alongside a side stile and measure the span between it and the opposite stile; divide by 2 to get the length for each rail, then cut them to size on a miter saw.

Step 13

Add the Rails

Cut two furring strips to fit between the baseboard and the line for the lower rail, and use them to prop up the rails on the door as you work. Glue the back of the right rail, rest it on the strips, and tack it to the door, as shown. Use the spacers again to install the door’s top right rail.

Step 14

Add the Center Stile

Measure and cut the ½×4 center stile to fit between the baseboard and the top of the door. Apply wood glue to its back side, and press it onto the door, nestled against the two installed rails and butted against the baseboard. Tack it in place with 18-gauge brads.

Step 15

Finish the Door

With the center stile installed on the door, use the furring strips as spacers to install the remaining two door rails, gluing and nailing them in place.

Step 16

Extend the Center Stile

Measure, cut, and install a ½×6 rail to fit between the side stiles along the ceiling. In this case, the top rail dies into a newel post, and a notched piece connects it on a diagonal to the right-hand side stile. Measure and cut the uppermost section of the center stile so that it extends below the jamb—allowing just enough clearance for the door to open. Glue and tack it in place, as shown.

Step 17

Scribe the Rail

Measure, cut, and install the upper right-hand rail. In our location, it had to be scribed to die into the diagonal rail. To do that, start by cutting the rail a little long, then dry-fit the piece with its corner overlapping the diagonal board. Align a straightedge with the intersecting slope, and use it as a guide to mark your cutline with a utility knife, as shown. Use a miter saw to cut off the excess. Glue and tack the rail with its bottom edge aligned with the end of the center stile you just installed, concealing the gap above the door.