Certainteed Adds Flyash to Fiber-Cement Siding
CertainTeed Corporation has altered the formulation of its fiber-cement siding lines to add recycled flyash. CertainTeed WeatherBoards and ColorMax fiber-cement siding lines now include 30 to 50 perce t flyash in addition to wood fiber, portland cement, and other additives. Cement is energy intensive to produce, and the use of flyash, a waste product produced by burning coal, has reduced the amount of cement required in some concrete applications in buildings. Research has shown that 100 percent flyash is feasible, though it has not been widely implemented, even within the sustainable design movement.
With the new fiber-cement formula, CertainTeed’s Lisa Santerian said, the flyash instead stands in for sand. According to Santerian, the wood fibers come from sustainably managed forests certified by an unspecified program. CertainTeed bills the new fiber-cement formula as lighter weight, lower density, and equally durable compared with its previous version.
Based on what you have seen and read about this project, how would you grade it? Use the stars below to indicate your assessment, five stars being the highest rating.

