How to Build a Secret Storage Compartment in Your House Wall

Locate and mark the wall studs on either side of area where you intend to build the secret compartment. Use a carpenter's level and pencil to mark horizontal lines on the wall between the studs, indicating the positions of the top and bottom of the compartment. Drill a hole with a 1-inch hole saw in the wall about halfway between the studs and about halfway between the upper and lower horizontal lines.

Begin cutting out the hole in the wall, using a jig saw. Cut across the horizontal lines until you reach the studs. Remove as much sheetrock as possible from the hole. When you can clearly see the studs, use a carpenter's level to mark their positions with vertical lines on the wall. Score through the outer paper surface of the sheetrock with a utility knife on the vertical lines. Use a hammer and chisel to cut through the sheetrock on the vertical lines. Remove the remaining sheetrock around the edge to create a rectangular hole.

Measure and note the distance between the framing studs in the wall. The top and bottom walls of the compartment will be trimmed to this length. Subtract 1/4-inch from this dimension to calculate the width of the compartment's door. This will allow 1/8-inch clearance on each side of the door so it will swing freely.

Measure, mark and trim two, 2-by-4-inch planks to the width of the space between the wall studs. Lay the trimmed planks on a flat surface with their 4-inch surfaces horizontal. Center an L-shaped bracket on each end of the planks. The bends in the brackets must be aligned with the of the ends of the planks with one leg of each bracket extending upward. The brackets are used to screw the planks to the framing studs to form the top and bottom of the secret compartment.

Cut a piece of string about 8 feet long. Tie it around the trimmed plank that you will use for the bottom shelf of the compartment. Should you drop the plank as you are installing it, you will be able to retrieve it with the string. Position the plank between the framing studs so its top is aligned with the lower edge of the cutout on the wall and the vertical legs of the brackets are facing upward. Screw the brackets to the corresponding wall studs, using a drill and driving bit.

Install the top of the secret compartment by placing the upper plank with brackets between the framing studs, in line with the upper horizontal cutout. The vertical legs of the brackets are facing downward. Screw the brackets to the studs.

Measure the height and width of the compartment. Subtract 1/4 inch from the dimensions to calculate the size of the door of the compartment. Use a carpenter's square to mark a sheet of 3/8-inch plywood to the size of the door. Trim the door with a jig saw. Drill a finger-hole handle through the door, about 1 inch from its opening side, using a 1-inch door-hole saw. Precise positioning is not important.

Lay the door on a flat surface. Open the piano hinge. Align the edge of one hinge plate to the opening edge of the door. The hinge pin will be parallel to the opening-side edge. Use 1/4-inch brads to nail the piano hinge to the door with one brad in each hole in the hinge plate.

Position the door in the opening at the front of the compartment. Fold small scraps of paper to make shims. Slide paper shims between the edges of the door and the frame. The shims will hold the door in place while you nail the piano hinge to to the frame. Nail the piano hinge to the corresponding framing member with one brad in each hole in the hinge plate.

Open the door. Measure and mark a spot 3/8-inch from the front edge of the approximate vertical center of the side wall of the compartment opposite the hinged side. Stack a few washers so their combined height is about 1/2 inch tall. Place the washers onto a wood screw. Position the screw and washers on the marked compartment wall so the front edge of the stacked washers is at the mark. Screw the washers to the inner compartment wall. The washers will serve as a door stop.