How and Why to Paint Material Other than Wood

Pressure Treated Wood
May 20, 2014
Interactive Color Design Tools
August 1, 2014

How (and Why) to Paint Vinyl, PVC, Concrete, and Cement Board

Vinyl and PVC siding are common alternatives to wood sidings in our region. You’ll also find concrete and cement board, both inside and outside of buildings. These are sturdy materials that, in many cases, don’t need to be painted. But vinyl and PVC colors will fade and get “chalky” over time, while the flat gray of concrete and cement board can be very dull to live with. A good paint job cures both problems.

None of these materials is difficult to paint; just don’t assume you can treat them like wood. There are differences in the preparation, choice of paint, and application that have to be taken into account in order to get a good result that will last.

 

1

Painting Vinyl and PVC

Vinyl and PVC products need to be cleaned before painting, and there are several factors to consider in choosing the right paint and paint color. First the cleaning:

• Power wash carefully, to avoid forcing water behind the siding. You can also hand wash with soap and water.
• Clean off mildewed areas with an oxygen bleach cleaner.
• Rinse thoroughly – soap and bleach residue will affect adhesion.
• Don’t paint until it’s completely dry.

There are three important considerations to choosing the paint. First, vinyl and PVC can warp if they get too hot, so choose a paint with high Light Reflectance Value (LRV, which is usually listed on paint chips and can labels). The higher the LRV, the more light is reflected, which means less heat and less warping.

Second, and for the same reason, it’s best to avoid a new color that is darker than the original color. Pick hues that are the same shade or lighter.

Third, Vinyl and PVC siding will expand and contract as the temperature changes, so the panels are designed to overlap loosely. This allows them to slide up and down over each other. However, thin strips of the original color may show in cold weather if the painting is done in very hot weather. The solution is to paint on cool days and when the sky is overcast or the sun is on the other side of the house. Don’t paint in direct sunlight.

Finally, use a high quality acrylic paint with a water/urethane base. Acrylics will adhere best to the smooth, non-porous surface of vinyl and PVC. You don’t need to apply a primer.

Painting Concrete and Cement Board

Heat is not the same issue with these materials, though dampness can be because they are porous. Again, the basic process is clean, prep, and paint, using products that are designed for masonry.

• Inside, clean off old paint with scrapers and brushes, and vacuum all surfaces to get rid of dust. Hand wash with soap and water.
• Outside, power washing can take care of both steps.
• Clean off oil and grease spots with tri-sodium phosphate.
• Rinse thoroughly and allow to dry completely – two days at least.
• Patch cracks, chips, etc. with cement patch material, and let it cure and dry thoroughly. (Follow the directions on the can.)
• Prime with a masonry sealer/primer. Again, let it dry completely. Any patched areas may need a second coat.
• Use a high quality acrylic paint.
• Apply 2 or 3 thin coats rather than 1 thick coat, and allow each coat to dry completely before applying the next one. (Follow the directions on the can.)
• In a very damp situation, you may want to apply a paint sealer as a top coat. Choose one that’s made to go with the paint you used.

The Final Touch

With both vinyl/PVC and concrete/cement board, a roller can speed the process, but you may want to brush out the paint to get the best surface look. Use a 3- to 4-inch brush made for latex/acrylic paints and work quickly, before the paint starts to dry. The end result will be an attractive and long-lasting finish.

Comments are closed.