Drywall panels cover most walls and ceilings built over the last 40 years. Drywall can also be called sheetrock, wallboard and gypsum board. These panels are made of a layer of gypsum sandwiched between heavy paper facings. A waterproof type, sometimes called “green board” because of the color of the paper, is used in bathrooms and other areas subject to heavy moisture.
These panels, which are relatively inexpensive, are four feet wide, 1/4 to 5/8 inch thick, and six to sixteen feet long. The standard size is 1/2 inch thick and eight feet long. They are applied to studs, joists, or rafters with drywall nails or screws, or with adhesive. Ceilings are normally “hung” before the drywall is applied to the walls.
After hanging, joints between the panels are “taped,” or covered with a paper or fiberglass tape and coated with several layers of smooth, plaster-like joint compound.
The corners of walls and windows can be left square or rounded (these “bull nosed,” corners have become increasingly popular in upscale homes over the last few years).
The final step is to finish the drywall by applying more joint compound to give the entire wall or ceiling a uniform appearance. People often elect to save money by keeping the walls in garages, storage and other work areas unfinished.
There are two basic drywall finish styles: smooth and textured. Drywall can be finished smooth for wallpaper (a layer of joint compound is applied over drywall and sanded) and smooth for paint (smooth for paint leaves a slight pebble finish). Many faux painting effects require smooth finishing as well.
Textured finishes can range from light to medium and heavy, with both simple and complex textures. A sprayed drywall texture is the most popular application method today because it requires less labor and thus less costly than hand-applied finishes. Fine to coarse grades of texture can be sprayed and left in place or quickly flattened with a hand trowel (“knock down” style). The finish can be made even coarser by adding textured granules (of foam, for instance) to the drywall compound before spraying. Thick layers of joint compound can also be hand troweled on to resemble old-fashioned plaster. This is most common on ceilings.
Most service professionals will bid basic drywall installation by the area and charge extra, if necessary, for special finishing. Be sure to discuss all the options available, asking for finish samples if possible, to understand what you are getting, avoid surprises and minimize or eliminate misunderstandings.