When Do I Use Primers for Painting Walls?

Porous Walls

• Most walls are made of porous materials, such as drywall and wood. Walls that have never been painted, or that have not been painted in a long time, are "thirsty" and will absorb large amounts of paint, which can result in an uneven finish or cause you to put on many more coats of paint than you anticipated, which raises your painting costs. A coating or two of primer seals the wall to prevent absorption, so your paint will go on smoother and more evenly. Unless your walls have been primed and painted within the last few months, a new coat of primer is necessary.

Changing Colors

• When you are drastically changing paint colors, the old color can bleed through the new color. A lot of coats may be required to cover chocolate brown or burgundy paint with white or cream. Don't think you are off the hook if you're going darker. White or bright color paints can bleed through darker colors as well. A way to save yourself a lot of paint and excess work is to cover your walls with a coat or two of primer. The primer will be even more effective if you tint it to match the new color you are putting on your wall.

Stain Blocker

• Old walls can have a number of problem areas, such as stains from nicotine, smoke, water, dirt, tannins and resins from certain types of wood and even smells from pets or smoke. If you paint directly on your wall, these stains and odors can be difficult to cover. Even worse, over time, they can eventually begin to bleed through again. In this case, a primer/sealer coating can prevent this disaster.

  Primer doesn't just keep wall stains from bleeding out, but it does prevent new stains and odors from seeping in. A stain-blocking primer can help prevent new leaks, smoke or stains from damaging your walls. Stain-blocking primers are ideal for rooms where moisture builds up, like bathrooms, or for homes that contain smokers, pets or children who might dirty the walls.

Surface Preparation

• If the surface you want to paint is papered, laminated or paneled, you may be worried that removing it would cost too much time and money. If you're tired of the outdated look, though, you don't need to live with it any longer. Use a high-adhesion primer to cover it and make the surface suitable for painting, which will ensure the paint will cover the surface and adhere to it, so your wall will be like new again. Ensure the walls are clean, sand any rough areas or rips, and smooth them out with spackle before priming so the primer will adhere well.