exterior building painterstest

By James Piper, P.E.

October 2017

The condition of paints and coatings makes a lasting impression on visitors and occupants as to how well an institutional or commercial facility is managed. Peeling or flaking paints and coatings create the impression of a poorly run operation and of a facility in decline.

But the impact paints and coatings have on operations go far beyond appearance. They are key elements in protecting building structures and components. If maintenance and engineering departments do not maintain them properly or if the wrong paint or coating is applied, deterioration of building systems and components will occur, shortening their service lives.

Advances in manufacturing technology and chemistry have resulted in an almost limitless number of options for paint and coatings, which is a blessing and a curse. The range of options allow for managers to match the characteristics of a paint or coating to the application’s needs. However, the range of options also increases the chances a manager will select an inappropriate product, one that does not offer the proper protection or the longest service life.

Compounding the selection problem is the range of prices for what might appear to be similar products. While the paint or coating with the lowest cost might seem to be a bargain, it might have a service life that is only half as long as that of a higher-cost product. With labor representing 70 percent or more of the total cost in projects involving the application of paints and coatings, the lowest-cost product usually turns out to have the highest life-cycle cost.

Ingredient insights

With all of the available options and a myriad of pitfalls, how do managers select the most appropriate paint or coating for their application? Managers can use several strategies early in the project planning process that will increase their chances of a successful application.

One of the most important considerations of quality is cost. In general, paint and coating costs increase with quality. It is that simple. Quality paints and coatings use higher-cost components, and they have higher concentrations of solids. They are easier to apply, hide surface defects better, bind to surfaces better, and resist peeling and mildew — all of which make them more expensive to manufacture.

The ingredients to a great extent, determine the quality of the paint. Managers can consult with the manufacturer to determine the paint’s ingredients and composition. What types of pigments and binders are used? What percentage of solids does the paint contain?

Pigments give paints and coatings color. Pigment volume concentration is the ratio of the pigment volume to the total volume of solids in the paint. The ideal for most applications is 5 percent. Higher values increase water permeability, while lower values tend to adhere better.

Binders in paint secure the pigment to the surface in a continuous film. A higher ratio of binder to pigment increases adhesion, crack resistance and durability. The higher the ratio of binder to pigment, the higher the paint’s quality.

A high concentration of solids is particularly important because the solids consist of the pigments and the binders in the paint and make up what remains when the paint or coating dries. When evaluating options, managers should look at the percent of solids the paint contains. It is typically 25-50 percent of the paint’s total volume. Again, the higher the percentage of solids in the paint, the higher the paint’s quality.

Paints and coatings come in finishes ranging from flat to gloss. To a great extent, the finish will determine how well the product will perform over its service life, so managers need to match the finish to the particular application.

For example, flat and eggshell finishes are good for hiding minor defects in surfaces, but they are not very durable and are more difficult to clean. Semi-gloss and gloss finishes are durable, easier to clean, and resist marking, but they tend to highlight defects in the surface.

Managers specifying paints and coatings need to look at all of these factors to identify the product that is the most appropriate for a particular application. Pricing, if managers consider it at all, should be secondary.