Paint Textures and Finishes
Walls and ceilings can be textured in two ways; by applying texture directly to the surface before painting or by adding textured material to the paint before applying it. Most commonly, texturing is included in the drywall installation process. However, many new products have been developed for use by painters to create "faux" and other specialty effects.
Conventional walls and ceilings consist of panels of drywall (or "sheetrock) applied to studs, joists, or rafters with drywall nails or screws, or with adhesive. Joints between the panels are covered with a paper or fiberglass tape and coated with several layers of smooth, plasterlike joint compound ("mud").
There are two basic drywall finish styles: smooth and textured. Textured finishes 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 uses less labor and is less costly than hand-applied finishes. Fine to coarse grades of texture can be sprayed. The texture is made coarser by adding textured granules (of foam, for instance) to the drywall compound or paint.
If you are matching existing drywall and having it professionally installed, it's important to let your service professional know the size and texture type so a more accurate estimate can be delivered. There are two types of smooth wall finish: smooth for wallpaper and smooth for paint (which leaves a slight pebble finish). Since wallpaper and many specialty faux finishes must be applied over smooth walls, it is often necessary to apply a "skim coat" or "float" drywall compound to fill in the "bumps" in previously textured walls to smooth them.
Textured finishes can also fall into "faux" finishes. Textured paints containing solid materials like silica can make walls resemble fabrics such as suede, for instance. New synthetic products developed to imitate old fashioned colored or white plaster can be applied smooth or hand-troweled into different patterns and styles. Textured products can create three dimensional effects by applying in layers to walls, fireplaces, ceilings and furniture to look and feel like real stone, crumbling masonry, peeling paint, fossils embedded in wall, etc. Some products and techniques can even be used outdoors.
"Popcorn" acoustic ceiling spray can often be removed and replaced with a new coat of texture to match the walls which is easier to keep clean and repaint. If the acoustic ceiling spray was applied before 1980, however, it should be tested for asbestos. If it contains asbestos, it would be far more economical to cover with a new layer of acoustic spray than to pay for costly asbestos removal.
-- Tips courtesy of HomeAdvisor.com