What you should know before you buy bamboo floors. 
 
The Forest Stewardship Council (FSC) has established principals of responsible forestry that members must follow in order to receive their certification.  This makes it relatively easy for consumers to know that the hardwood floors they are purchasing were grown, harvested, processed, and distributed responsibility.
 
Unfortunately, there’s no certification process for bamboo forests, most of which are in China.  And when it comes to responsibility, there’s a pretty big disparity among bamboo floor producers.
 
Because bamboo flooring is selling so well in the United States, many Chinese producers are using fertilizers and pesticides to maximize their output.  In some cases, they’re harvesting the bamboo before it’s fully mature.  And the use of adhesives that contain urea formaldehyde in the lamination process or finishing is pretty common.
 
Formaldehyde emits Volatile Organic Compounds (VOCs) that are hazardous to human health, especially to those with asthma or other respiratory problems.
 
As a general rule, the less expensive the bamboo flooring, the more likely it is to contain dangerous amount of toxic chemicals.  There are manufacturers who do not use urea formaldehyde or use low-VOC compounds for bonding and finishing.  And reputable wood flooring companies will be able to provide you with specific information about the amount of VOCs emitted.
 
Don’t install inexpensive bamboo flooring until you know whether or not it complies with American VOC emission guidelines.  You certainly don’t want to risk making yourself or your family ill in order to save a few dollars.
 
Although bamboo is touted for it’s hardness, bamboo that’s harvested before it’s completely mature, steamed to create a darker color, or processed with cheap compounds will not stand up to much wear and tear.  Although bamboo floors are generally less expensive than hardwood floors, bamboo flooring is an investment that you should be able to amortize over many years of use.
 
To check the hardness and finish of a bamboo floor, scrape the face of the flooring with a quarter.  If the finish flakes off, don’t buy it.  If it passes that test, see if you can mark it with a fingernail.  If it scratches easily it probably won’t be durable enough to stand up to every day traffic.
 
To extend the life of your bamboo floors, use area rugs to protect them and clean them according to the manufacturers recommendations.

Learn more about bamboo floors here.   Or learn about other kinds of wood flooring here.

Aside from the appearance, which is elegant and sophisticated, what attracts most people to bamboo floors is bamboo’s renewability.  Unlike hardwoods that can take up to 150 years to mature, bamboo reaches maturity in five to seven years.

What’s more, harvesting doesn’t kill the plant. The root system remains intact and after the stalk is cut, new shoots sprout up. 

Harvesting the bamboo stalks. 

Bamboo is harvested by hand when it’s  mature.  The stalks are put through a machine that splits them, cuts them all to the same length, removes the knuckles or knots, and peels off the skin. 

Bamboo should be harvested during the lower-moisture season — fall or winter.  Bamboo that’s cut down in summer may end up splitting when it’s dried because of the higher moisture content.   And the stalks should be processed right after cutting to prevent the growth of mold. 

To kill off insects, starches, and sugars, the strips are boiled in water and preservatives.   After boiling, the strips are air dried and then kiln dried for up to five days to reduce the moisture content.  A moisture content greater than 10% could result in boards that crack or ripple in dry climates. 

Bamboo is naturally a beautiful, pale color.  But carbonization can be used to darken the wood if a darker colored bamboo floor is desired.  Steam heats the bamboo until the sugar in it caramelizes, resulting in warm, amber color.  The steaming process softens the bamboo, so generally speaking, the lighter the bamboo, the harder it will be and the better it will wear. 

Making solid bamboo flooring.

After the boards are produced, they’re graded, and the strips are glued together — 15 strips face up for horizontal flooring and 19 strips side by side for vertical floors.   The strips are heated and pressed together to form boards called blanks. 

Most bamboo flooring is made in China, where formaldehyde-based glue is often used in the manufacturing process.  These bamboo floors can emit Volatile Organic Compounds (VOCs) that can cause health problems.   Reputable manufactures ensure that their flooring complies with safety standards.  Inexpensive flooring may not be in compliance. 

The blanks are cut to the desired length and then milled into floor boards with tongue and groove edges.   A sanding belt is used to smooth out the boards and give them a uniform surface. 

Before being shipped, the boards are coated, usually with an aluminum-oxide urethane finish. 

Making strand-woven bamboo flooring.

Bamboo that’s over 50 feet tall is referred to as timber.  It’s used to make strand-woven bamboo flooring.  The timber is shredded, and the fibers are bonded together with an adhesive resin under extreme pressure.   The fiber mixture is molded into blocks which are later milled into boards.

Strand-woven bamboo flooring is not only beautiful and distinctive, it’s some of the hardest, most durable flooring you can buy.  In fact, it has twice the hardness of red oak. 

Learn more about the different types of bamboo flooring here.

A horizontal bamboo floor will show the knuckles or nodes that appear every foot or so in the bamboo stalk.   This gives the flooring a very distinctive look.  To make horizontal flooring, 1” strips are laid face up and then glued together.   The boards are then milled to size, usually around 3-½” wide. 

Because the knuckles are less apparent, vertical bamboo flooring has a more uniform, even grain and a more refined look.  It’s comprised of 19 strips of bamboo, placed side by side and then laminated together.  

Solid bamboo flooring.

While other solid wood flooring like oak or maple is made from a single piece of wood, solid bamboo flooring is actually made of pieces of bamboo that have been laminated together — either horizontally or vertically, as discussed above. 

Usually about 5/8” thick, solid bamboo flooring can either be nailed or glued down.   This is a key difference from solid wood flooring, which has to be nailed down.

Woven bamboo flooring.

For high-traffic areas where extra hardness is desirable, woven or strand-woven bamboo floors are a good option.  To make woven flooring, timber bamboo — stalks that are 50’ or taller — is shredded into fibers or strands, bonded together with resin, and then molded into blocks. 

When the resin has set, the blocks are milled into boards that are usually a little over ½“ thick.  It’s important to know the type of adhesive that was used to bond the strands together.  If it contained urea formaldehyde, it could emit harmful fumes. 

The final product has a hardness of 3000 on the Janka scale, making it more than twice as hard as red oak.  And the grain looks more like conventional wood flooring. 

Woven bamboo flooring can be nailed down or glued.  So you can use it if you have concrete sub floors.  But because of the hardness, it’s difficult to nail and may split if you don‘t pre-drill the holes. 

Engineered bamboo flooring.

Solid wood floors can’t be installed over concrete sub flooring, so engineered wood floors that can be glued down were developed.  Engineered floors are comprised of several layers or plys — a top layer or veneer that’s usually around 1/8” thick, a core, and a base of compressed particle board or plywood.  

To add stability, the grains of the core layer are laid in different directions.  This works fine when the veneer is wood, which can expand and contract with the core.  But because the veneer in engineered bamboo floors is a composite, it may not expand and contract along with the core.  Consequently, the top layer of engineered bamboo floors is more likely to crack than the face of engineered hardwood floors. 

For this reason, engineered bamboo floors are not recommended.   Solid bamboo or woven bamboo are more reliable. 

Bamboo floor color choices.

Bamboo is naturally a lovely, light blonde color.   But a darker color can be produced using a process called carbonization.  Bamboo strips are heated until the sugars in the stalks caramelize, which turns them a warm, amber color. 

The carbonization process softens the bamboos, so darker bamboo floors aren’t suitable for high-traffic areas or homes with big dogs. 

You can learn more about how bamboo flooring is manufactured here.