Wednesday, December 16, 2009

Elastomeric Coatings

By: Tim Flood

There seems to be a lot of confusion about Elastomeric Coatings in the market place. Most of our customers are convinced that Elastomeric Coatings can not be applied on wood substrates such as wood siding. I am hoping to shed some light on the discrepancies that exist between contractors and home-owners.

My background is in both paint manufacturing and contracting and we have been involved with both on some level since 1987.

I'll start with the basic function of an elastomeric coating, what types are available for home owner use and the facts of elastomeric coatings as they relate to wood.

Elastomerics Coatings were originally developed as a water-proof coating or membrane designed to keep water (rain) from penetrating concrete warehouses in areas that were prone to wind driven rains. The idea was to keep moisture from damaging the contents of the warehouse or building. They were typically very thick coatings applied in two separate coats, the second designed to be pin-hole free to prevent water intrusion. The final dry-film thickness would be 16-20 mils (8-10 times thicker than house paint). The coating was designed to very flexible or elastic to compensate for movement or settling and to bridge any cracks from reappearing.

As time progressed painting contractors began experimenting on combining elastomeric Coatings with house paint for several reasons, the first being the need for a coating the could create a higher film build to fill in the cracking and checking on weathered wood siding. Painting contractors were aware of the benefits of using elastomeric coatings on concrete and stucco substrates to fill and bridge cracking and the fact that elastomeric coatings were a thick, high viscosity, high film build coating, they were also aware that the cost was thirty to fifty percent higher than the typical house paint not to mention the fact the spread rate – coverage was 50-75 square feet per gallon compared to 300-400 square feet coverage of a quality house paint. Contractors realized that by combining an elastomeric coating with house paint that the spread rate would increase and the combined products would fill the cracks in wood siding. As a result of using this combination contactors were delivering a finished product that was truly impressive compared to the contractors that were using the conventional house paint.

Manufacturers had serious concerns with painting contractors altering products in the field with no quality control systems in place, no formal testing, and no known outcome on performance or coating failures and were reluctant to endorse or develop a product that would meet the demand and needs of their customers.

In 1997 while I was employed as the Vice President of Sales for a small paint manufacturer in Sacramento I decided to contact several key resin manufacturers about the possibility of developing a resin / elastomeric system for wood that did not trap moisture, pick-up dirt or need to be mixed on the job-site. As a result of the meetings we were able to produce a resin system that could achieve the film build we were looking for that included a perm rating (Water entrapment) similar to traditional house paints with better dirt resistance, color retention and life expectancy of traditional coatings already in place.

Since the formulation of the original batch in 1997 there have been thousands of homes (Both wood&stucco;) that have been painted with these new hybrid elastomeric coatings. Nearly every manufacturer has included this type of elastomeric in their product line. After researching the brand name manufacturers such as Vista Paint, Sherwin Williams, Dunn Edwards and others, I have confirmed that they do in fact recommend elastomeric coatings such as Weather-Master 1900, for wood siding and other wood substrates.

I hope that this article has been helpful to you in answering some of the questions that surround elastomeric coatings. There are several web-sites and articles that have been published by industry experts that may be helpful in answering any remaining questions that you may have. Please visit http://www.werentpainters.com/

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