What Nap to Use on Smooth House Walls?

Significance

• While you can paint any surface with any roller cover, using the proper nap ensures that you get the best possible results. If you use the wrong size nap when painting your walls, paint bubbles may form during application. These paint bubbles burst as the paint dries – leaving you with a wall covered in small, round depressions. Using the correct nap the first time saves you from having to repaint your wall to erase your previous mistake.

Painting Smooth Surfaces

• The smoother a given surface is, the shorter the roller cover's nap should be. Aubuchon Hardware notes that a 3/8-inch nap is typically best for applying paint to interior walls, but you can use a roller cover as short as 3/16-inch if you wish. There are exceptions to this rule depending on the type of paint you are using. For example, if you are applying enamel paint, you should select a roller cover with a slightly longer nap of 1/4-inch.

Nap Material

• The length of a roller cover's nap is not the only factor that influences the results of your paint job. The type of fiber the nap is composed of also plays a role. Synthetic fibers are common and work well for applying latex-based paints. If you are applying an oil-based paint, however, Ace Hardware recommends choosing a mohair nap or a nap made up of a blend of lamb's wool and polyester. Specialty naps such as these are slightly more expensive than synthetic naps.

Considerations

• Just because your wall is smooth to the touch does not mean that it's perfectly smooth. While you cannot see it with the naked eye, your walls contain tiny ridges, pits and depressions that affect how paint sticks to the wall and what the wall will look like once the paint dries. Apply primer to ensure you have the smoothest surface possible before painting. In addition to giving you a smooth base coat, primer also prevents the old paint from absorbing any of the new paint. This reduces the number of coats you must apply.