A. My personal experience with
bamboo flooring has been mixed. Granted, bamboo is one of the
most important plants in the world, having a wide range of
uses. It grows fast, regenerates without replanting, and
requires no fertilizer. It reaches a mature height of 100 feet
in just five years, making it an appealing renewable resource.
Most commonly used in Asia, it has lately become fashionable in
the West as a flooring material. But while many manufacturers
promise superior hardness, the reality is that the hardness of
bamboo flooring is highly variable. Some bamboo floors I've
seen dent and scratch fairly easily, with as little as a
fingernail, for example (see photo, below). Red oak doesn't do
that. On the other hand, the superior hardness that is
routinely promised can also be found.
There are several reasons for this inconsistent performance.
The properties of bamboo depend on the season when it's
harvested, the environment in which it was grown, the amount of
rain and sun it has received, and its age when harvested.
Immature two-year-old bamboo is weak and typically sold at a
discount in the open market. Bamboo harvested at five years is
better and more expensive. So, as a starting point, it's not a
good idea to buy the cheapest product. Also, there are more
than 700 species of bamboo, so the potential for variability
among flooring products is great.
Another cause of inconsistency is the way that bamboo lays down
cells as it grows. It's denser toward the outside of the shoot
and softer toward the inside. So the density of the flooring
depends on where the actual fiber comes from. A good
manufacturer understands this and arranges the fiber
accordingly.
In the cross section (see photo, below), you can see that small
strips are cut from a bamboo stem, then laminated together to
manufacture the flooring. You can even see where one of the
laminated pieces was taken from the softer, inside surface of
the bamboo stem. This is the strip located directly under the
scratch in the top photo.
My best advice is find a reputable manufacturer and distributor
who have a solid track record and will stand behind the
product. Ask how they test for and assure hardness values for
the product. Request technical literature that explains how the
product was made from harvesting through lamination and
finishing. The literature should be convincing. If hardness is
critical, choose a natural color: Natural colors are
significantly harder than the "carbonized" darker colors, which
are produced by pressure-steaming the wood, resulting in a
significant drop (~25%) in hardness.
Unfortunately, the introduction of bamboo flooring is recent,
so to date there is no governing association like the National
Oak Flooring Manufacturers Association providing oversight and
quality control.
Paul Fisette is director of Building Materials and
Wood Technology at the University of Massachusetts at Amherst
and a contributing editor to
The Journal of Light
Construction