Drywall going up on one of our projects is always a welcome sight. It means that we are in the “final lap,” meaning the structural, mechanical and electrical components of our project are complete. As we’ve evolved into a greener construction company, choosing the right drywall has become a major conundrum. The harmful affects of Chinese Drywall and gypsum have been in the news a good bit lately and we’ve been researching alternatives.
Fortunately our company never used any Chinese-manufactured drywall in our projects, mostly because we try to buy local. As it turned out, Chinese Drywall had unusually high levels of hydrogen sulfide, which significantly increases corrosion of metals, specifically silver and copper. Claims are that it blackened metal in or near electrical fixtures, appliances, plumbing and air conditioner coils.
From my perspective, the Chinese Drywall situation occurred because of a shortage or created shortage of drywall supply in the U.S. Last week the Department of Housing and Urban Development released a report stating they recommend complete removal of all “Chinese Drywall.”
Beyond the Chinese drywall problem, paper wrapped gypsum drywall was one of the great postwar building material advances. It replaced lath and plaster, making the construction process faster and less expensive. The downside is that gypsum drywall is made of calcium, sulfur and water. The production is a major contributor of greenhouse gas.
The process starts with crushed gypsum “cooking,” which removes the water but also produces tremendous amounts of CO2 and water vapor. The dried gypsum is mixed into a water-based slurry and wrapped between thick sheets of paper. This “wet” drywall must then go into a gas fired drying process again, which produces even more CO2 and water vapor. The production of gypsum drywall combined with the production of cement creates nearly 12% of the manmade CO2 in our atmosphere.
So we’re back to the original question: Can drywall be green? The answer is for now, it can be green-er, but we’re looking for ways to make it entirely planet friendly. Here’s how:
RESEARCH. Several manufacturers are trying to find new approaches to reduce or eliminate the CO2 and water vapor results of gypsum drywall production.
ECO ROCK. Produced by Serious Materials, this drywall uses “slag” from steel and glass blast furnaces. Slag is a leftover that furnace operators used to throw away. Although there’s been CO2 in its making, the logic is we might as well use it as it’s already dehydrated, can be made into slurry and pressed between fiberglass sheets. It doesn’t need to be dried, so both CO2 producing processes are eliminated.