What’s In Your Paint?
By Steven A. Watchorn, Assoc. A.I.A., LEED AP
It has astounded me how often the major U.S. paint manufacturers change their line of paint. In recent years, with advances in synthetic and resin technologies, more stringent VOC regulations, LEED compliant products, and increased competition between manufacturers, lines of paint have been changing ever more frequently.
Whether you are a building industry professional, a homeowner looking to put a fresh topcoat on your deck or siding, or a painter yourself, these changes are likely to overwhelm you; the paint you used, specified, or priced just a couple of years ago is probably out-of-date or no longer available! It is at this point that we must take a step back and re-consider the basics of our paint options.
Named for their binding agent, the primary commercial paint systems available today are the oil-based (alkyd) paints, which use petroleum solvents, and the water-based (acrylic-latex) paints. They each have co-existed for a very long time and each has their benefits and drawbacks. Oil-based paint systems have unmatched adhesion properties, and spread more evenly, but dry slower and have a strong odor. Water-based paints can be applied more quickly between coats and cleanup is easier and more cost effective.
Projects involving restoration of exterior wood are largely concerned with preventing peeling, crazing, or blistering paint, and extending the life of the paint before reapplication is necessary. Although the most important criteria for a good paint job is surface prep, selection of a good primer and compatible top-coat systems can add years and beauty to your building and should not be undervalued.
Older paints that contained lead or oil solvents high in VOC content lasted much longer and withstood temperature changes, moisture, and UV penetration much better than today’s paints. While society is now aware of the benefits of safer, environmentally-friendly products, the loss of high quality paints that will last 20+ years is putting a huge financial strain on building owners. The paint manufacturing market has responded in part, overhauling their paint lines. But this change, in addition to the multitude of offerings of ‘specialty paints’ has added to the overwhelmed state of the consumer. Still, re-painting of exterior wood should be done every five years.
While it may still take some time to bring the available paint offerings, and the demand for high-quality affordable paint back in harmony with each other, preservation and sustainability of our buildings, whether new or old, should take precedent over all else.