How to Build a Room in an Unfinished Basement

Examine your basement to be sure that there are no leaks, mold, mildew or other indications of excess moisture. These problems can be solved, depending on their severity, with solutions ranging from a dehumidifier to excavation and exterior waterproofing.

Frame the walls of the room to the exact height of the distance between the basement floor and the underside of the ceiling joists. Tilt the walls up into place and secure them to the underside of the ceiling joists using 3-inch-long screws.

Build a finished floor in the room by framing it with 2-by-6 lumber and covering the flooring frame with 3/4-inch plywood. Raising the finished floor off the basement floor helps keep the finished room dryer and warmer.

Attach drywall to the underside of the ceiling joists to create a finished ceiling within the room. Attach drywall to the interior surface of the walls that you framed.

Spackle over all holes made by the screws as well as the joints between the drywall sheets. Apply drywall tape to the joints between the drywall sheets. Apply another coat of spackle over the drywall tape, feathering it out to make it as smooth as possible. Let it dry for 24 hours

Sand all of the spackle smooth. Paint the ceiling and walls with a coat of primer. Paint the ceiling with two coats of white ceiling paint and the walls with two coats of finish paint in the color of your choice.