How to Build a Platform Bed on a Wall Unit

Examine the bottom of the wall unit to locate a point where you can attach the platform bed. If there is a central cabinet for placing a television, this may prove the perfect spot after removing the cabinet body. You’ll need a space at least 39 inches wide for a twin bed, 54 inches for a full-size mattress, or 60 inches for a queen.

Remove the central cabinet of the wall unit with a screwdriver to provide space for placing the platform of the bed. Measure the width of the space provided by removing the cabinet, using a tape measure. Choose a mattress for the platform that’s closest to the width without going over.

Measure the length of the mattress.

Cut five two-by-four planks with a circular saw to match the interior width of the cubby space created in the wall unit with the removal of the cabinet, less three inches. Cut two more planks to match the length of the mattress.

Place the width planks between the length planks to form a rectangular frame, with the width planks flush with the ends of the length planks. Check that the joints are square by placing a carpenter’s square inside of them and making sure each is set at a 90-degree angle. Nail the joints together with a hammer and 10d nails. Use two nails at each joint, driven through the length pieces into the ends of the width pieces, and staggered to avoid creating a crack in the wood.

Set the last three width planks between the length planks for additional support. Place one plank in the middle of the space, with the other two set equally between the center and end boards. Nail the three support boards into place. Add more support to the frame by cutting two-by-four planks into four 4-inch-square blocks, then nailing a block into the four frame corners.

Cover the frame with a 3/4-inch plywood sheet, cut to fit flush with the frame’s width and length. Attach the sheet to the frame with a nail placed every six inches around the frame edges and every eight inches across each of the cross support boards.

Flip the frame over. Construct a second frame from two-by-six boards that is 10 inches shorter in length and width than the first frame. Center the second frame to the first, then nail the frame in place by directing nails through the sides of the second frame and into the support boards of the first at an angle. Flip the frame back over so that the platform is on top.

Sand all cut edges smooth with fine-grit sandpaper. Wipe the sanding residue off the frame with a tack cloth. Stain the frame whatever color you wish, spreading the wood stain in place with a foam applicator. Allow the stain to dry overnight.

Move the bed frame into the space of the wall unit where you removed the cabinets. Drill pilot holes through the both sides of the wall unit adjacent to the space and into the sides of the two-by-four frame using a drill with a 1/2-inch bit. Only drill to a depth equal to the width of the cabinet edge plus one inch. Place a hole every six inches through the cabinet into the frame.

Secure the frame in place by screwing lag bolts through the sides of the wall unit and into the frame. Make certain the bolts used are not long enough to penetrate through the two-by-four planks of the frame. Tighten the bolts in place with a socket wrench to complete the connection.