How to Finish a Walk Up Attic

Insulate the spaces between the floor joists and the wall studs. Use insulation batts with facing that are the appropriate R-value for your climate, typically R 30 or R 38. Set the batts in place between the studs or joists with the facing toward the room. Use wire fasteners to hold floor insulation in place. Friction holds the wall batts in place.

Lay a subfloor if the attic doesn't have one. Apply a bead of construction adhesive to the top of a joist, set plywood in place on top of it and screw the plywood to the joists, ensuring that each edge of a sheet of plywood is screwed into a joist. Use about eight screws evenly spaced on each side and five on the middle joist. Leave a small space between plywood sheets so the subfloor can expand and contract.

Measure the attic walls for drywall. Set sawhorses up in the attic and lay a piece of drywall across them with the finished side up. Measure the attic wall and cut the drywall to fit if necessary. When measuring, take into account that two pieces of drywall will share the same stud when they're screwed in side by side.

Use a carpenter's square to ensure that the cutting lines on the drywall are true. Set a sturdy straightedge along the line and cut the drywall with a utility knife. Press down firmly to make a clean cut. Position the drywall so that the cut is not resting on a sawhorse. Hold the drywall near the cut with both hands spread as far apart as possible and snap downward. Use a helper for long cuts. Flip the drywall over and use the utility knife to cut the paper backing along the line.

Install the drywall with drywall screws. Screw the drywall into the studs along both sides and along any studs in the center of the drywall. Space screws about 6 inches apart. Spread a thin layer of joint compound over the screw heads in the center of the drywall. Scrape off any excess joint compound. Spread joint compound along the seams between the sheets of drywall and scrape off any excess. Cut a piece of drywall tape the length of the seam and press it into place. Run a taping knife along the tape to remove excess compound behind the tape and apply a thin layer of compound to the top of the tape. Allow it to dry thoroughly then sand it smooth.

Apply a coat of primer to the walls and allow it to dry before painting the walls. Install baseboard and crown molding, if desired, and finish the floor with carpet, tile, laminate or hardwood.