Installing paneling over existing drywall is a fairly straightforward process. As with most building projects, proper planning and preparation will make it easier for you to get professional looking results. The preparation phase of the project may take longer than the process of actually installing the paneling, but it will be time well spent. A few extra hours preparing at the beginning of your project can make the difference between results that will last for years and a job that needs to be redone in a few months.
Stack your paneling in the room where it will be applied. Allow it to sit for at least three days before installation. Wood paneling will contract and expand with changes in temperature and humidity. It is a good practice to allow it to adjust to room conditions before installation.
Clean your drywall. The surface of the drywall must be free of loose dirt or oil for proper adhesion. Textured walls must be sanded smooth and all dust removed with a vacuum before your paneling can be installed.
Remove all switch plates and outlet covers from the walls before you begin paneling. You'll replace them after your paneling is complete. Removing them all before paneling will make it easier to get accurate measurements for the necessary cutouts.
Trim the top and bottom of the first panel to leave a 1/4-inch gap between the ceiling and the floor. Turn the panel face down when trimming with a circular saw or saber saw. When using a table saw, trim with the panel face up. The blade should cut into the finished face of the paneling to prevent tear-out and chipping on the finished side of your panels. The gaps allow the panels to expand without buckling the walls during periods of high humidity. Cover the gaps with molding after all of your paneling is in place.
Measure and cut any necessary cutouts.
Place the first piece of paneling in a corner of two walls. Use a level to check the outer edge of the first panel. This must be plumb, or the remaining panels will necessarily be crooked. Trim the inside edge (the edge in the corner) of the panel, if necessary, to allow the panel to hang properly. Once you are satisfied with the fit, remove it from the wall and place it face-down on the floor.
Use a caulking gun to apply wavy vertical lines of construction adhesive, 16 inches apart to within 3 inches of the top and bottom of the board. Apply a bead of adhesive 3 inches around any opening for outlets as well. Apply a solid bead of adhesive horizontally 3 inches from the top and bottom of the panel.
Press the panel in place on the wall. Tap the entire surface of the panel lightly with a rubber hammer to flatten and set the adhesive. You can secure the panel with a small finish nail in each corner if you are using a slow-curing adhesive. You should place these nails where molding will cover them after the molding is installed.
Trim and place your remaining panels using the same methods described above. The sides of your panels should be butted together evenly, without gaps. Maintain a 1/4-inch gap at the top and bottom for all panels.