Optimum 5.5® Moso bamboo, a Teragren exclusive
For our bamboo products, we specify only Teragren Optimum 5.5 Moso bamboo grown in the Zhejiang province of China. There are more than 1,500 species of bamboo and moso (Phyllostachys pubescens) is among the hardest, with dense fibers that make for strong timber and beautiful, durable bamboo flooring, panels and veneer. Bamboo has greater compressive strength than concrete and about the same strength-to-weight ratio as steel in tension. But it doesn't start out that way. To achieve the characteristics valued in construction material, it must be harvested at the right time, between 5-1/2 and 6 years.
Even fast-growing bamboo needs time to mature
Like all bamboo, each culm grows rapidly from a rhizome. Moso has been known to grow 47 inches in 24 hours, but it generally reaches its maximum height of 80 feet within just two months. After that, growth occurs within the stalk. The walls of the hollow culm thicken inward as chlorophyll, sugar and organic material are changed into dense, fibrous cellulose. It is these reinforced but lightweight internodes that provide tremendous strength with flexibility along the entire length of the bamboo culm.
Young shoots of moso are so tender that they can be harvested as a culinary delicacy (for humans, not panda bears). One-year-old culms are still soft and can be used to make fine calligraphy paper. At four years of age, fiber development in the culm is more appropriate for pulp and paper manufacturing than bamboo flooring.
When the bamboo reaches maturity at 5-1/2 to 6 years, its fibers are at peak density—and it's time to harvest. By using only Optimum 5.5 Moso bamboo harvested in this way, Teragren ensures that our products are harder and more stable for lasting beauty and performance.
Hardness measured by the Janka ball test
The hardness of bamboo that is key to durability is established by the Janka ball test. The Janka ball test measures the force required to embed in the wood a .444-inch steel ball to a depth of half the ball's diameter. Teragren Signature Naturals flooring averages a Janka rating of 1921. By comparison, white oak registers 1360, North American maple, 1450. Teragren Synergy™ strand bamboo flooring with Xcora™ technology, made by a patented process with optimized manufacturing, is rated at 3271. (View hardwood hardness comparison chart.)
Bamboo is more resistant to moisture than hardwoods. In products like bamboo flooring, that means less contraction and expansion with changes in moisture—during installation and throughout the life of the floor, even in humid or dry climates.
Moso bamboo timber has been used in construction for thousands of years. In Asia, homes, bridges and multi-story scaffolding are made of moso timber. In South American earthquake zones, bamboo has been used to build thousands of homes because its flexural strength helps the homes withstand temblors. Plywood made from moso performs well as flooring for truck beds, trains and containers. Other uses of moso bamboo include furniture, beds, mats, chopsticks, baskets, musical instruments and handicrafts.