For Healthy Walls, Think Plaster

(This appeared in April '10, Merchant Magazine and Building Products Digest)

Whether it’s new construction, remodeling or home improvement, the ultimate goal is to create a healthy, comfortable space for the occupants. It’s an art, of course, but there’s some real science behind understanding how various building components interact to maximize indoor air quality, while minimizing mold growth and energy demand. It turns out that wall “breathability” may be one of the most important components determining long-term indoor air quality and occupant comfort. This isn’t going to be a science lesson. But this kind of thinking is becoming more mainstream, creating new opportunities for dealers to begin supplying solutions.

Interesting thing about walls: they all get covered, coated or stained and almost every dealer in the supply chain sells one or the other or all three. Paint is the most common coating and every dealer who sells paint carries at least one line of “green” paint, or is considering adding a line right now. The number of “green” paint brands has exploded over the last year or two, with nearly all the major national and regional manufacturers marketing some pretty good to great products. The greenest paints, of course, are the ostensibly non-toxic, zero-VOC formulations, coupled with zero-VOC colorants. The demand is there and growing, and the products are easy find, so getting into a good green paint brand is a no-brainer at this point.

But there are limitations with paint and that, in part, is driving more interest in lower impact, healthier, and, surprisingly, more traditional alternatives. Manufacturing paints requires a fair amount of energy and requires lots of chemicals, even for the green brands. Paints have limited durability requiring touch ups and re-application every few years. Paints also seal, keeping moisture out, but also keeping moisture in. They’re not breathable, potentially creating the conditions for mold to grow within the walls, which is one of the main causes of “sick building syndrome.” These factors have contributed to a significant rise in the use of traditional plasters, or more up-to-date versions of traditional plasters, that have relatively low-embodied energy, are non/low emitting, breathable, durable, and have other interesting properties.

One of the best known examples is American Clay, (www.americanclay.com), an interior clay plaster line made in New Mexico. Because it’s breathable, it helps to moderate humidity in a room and allows for air exchanges that reduces or eliminates condensation within walls. According to a company announcement at GreenBuild last fall, the products also exhibit moderating effects on temperature that may lead to lower energy bills. In other words, versus paint, rooms with American Clay stay cooler in the heat and warmer in the cold.

Another modern-traditional innovation just coming into the US market from Japan is EcoDeVita, from Shikoku International, (www.ecodevita.com.) Two products in the line contain diatomaceous earth and have the very unique property of adsorbing formaldehyde and chemically breaking it down, rendering it harmless. Not only does it provide all the other benefits of a traditional wall plaster, but it also cleans the air, too.

Orit Yanai, (www.orityanai.com,) a LEED Accredited Professional and one of the industry’s top experts on plasters, thinks that demand for sustainably produced, multi-functional plaster products like these will continue to grow. “One of the biggest topics in the green building community right now is about breathable walls and the good news is that the solution has been around for thousands of years – plaster,” she tells me. “But having said that, it’s not always easy to source materials for a project.” A few minutes on Google indicates the current dealer mix includes those that specialize in plaster and related products, green-building boutiques, and a handful of more traditional LBM dealers. If there’s growing demand that’s under served, traditional LBM dealers could leverage natural advantages in scale and contractor relationships to make green plasters a healthy new line of business.