Moisture - The Curse of Great Paint Jobs Everywhere

Moisture - The Curse of Great Paint Jobs Everywhere

Three difficult exterior issues that affect paint appearance and longevity are all caused by excessive moisture. Minimizing the moisture problem first and then renewing the substrate with quality Diamond Vogel paints is the key to success.


Mildew is an unsightly fungus that can grow on many surfaces including paint. The mildew feeds on nutrients available in both the paint film and the underlying surface. Most important for mildew growth is moisture, so it is commonly found in damp, dark places frequently under eaves and behind shrubbery.

Mildew must be removed prior to painting. Mix one part of bleach with three parts of water. Scrub the area thoroughly while protecting yourself by wearing rubber gloves, eye protection and other protective clothing. Don’t allow the bleach/water mixture to dry out on the surface. Rinse the area thoroughly and allow the area to dry. Repaint the area as soon as possible. We recommend two coats of Diamond Vogel's Permacryl Exterior, Weather-Plate, or EverCryl Acrylic Latex.

Allowing more sunlight and better air movement to reach the affected area will help minimize the return of the mildew, so pruning trees and thinning shrubbery are important steps.

Tannin Staining

Tannin is a naturally occurring, water soluble substance found in many varieties of wood. Tannin can be pulled to the surface in the presence of water and leaves behind a brown or tan stain. Tannin staining issues are more likely to develop from red cedar, cypress and redwood. While these stains do not harm the integrity of the paint film, they are unsightly.

The best way of preventing tannin staining is by applying a tight film of paint over the substrate minimizing the ability of water to penetrate. In the past, solvent-based alkyd primers were the choice to prevent tanning staining. However, solvent-based primers tend to become brittle, crack and peel with age.

Diamond Vogel developed Sure Grip Exterior Acrylic Latex Primer to combat tannin staining and peeling issues on exterior wood substrates. Sure Grip applied in two coats with twenty-four hours in-between coats, does an amazing job preventing tannin bleeding. Topcoat with Permacryl ExteriorWeather-Plate, or EverCryl Acrylic Latex for a long lasting, beautiful paint job.


Efflorescence is a white or tannish, powdery deposit on concrete or masonry substrates. While typically not structurally damaging to the substrate, it is unsightly and destroys the paint on the substrate. Efflorescence occurs when moisture migrates through concrete and masonry substrates, dissolving salts contained in the material. The moisture deposits the salts on the surface of the substrate and evaporates, leaving the powdery deposit.

Prior to rectifying the ruined painted surface, the source of the moisture must be found and stopped, or the process will reoccur. Once the moisture has been stopped, remove the existing efflorescence and loose paint by using a stiff wire brush. Clean the surface to remove all the dirt, debris and other contamination.  Prime the surface with either Diamond Vogel's Weather-Plate Exterior Acrylic Latex Primer or Sure Grip Exterior Acrylic Latex Primer, followed with your favorite color in either Diamond Vogel's Permacryl ExteriorWeather-Plate, or EverCryl Acrylic Latex.

Whatever paint challenge you’re experiencing, Diamond Vogel has the answers and products to make your project last. Stop by any of our 70 service centers for proven answers for your project. We’ve been providing quality, coating solutions since 1926, and we love to help.