Since the mid 90s, bamboo has been marketed as an eco friendly option for flooring. As the world’s fastest growing plant, it is infinitely renewable and requires little in terms of irrigation, fertilizers or pesticides. Yet, there seems to be some debate with respect to bamboo flooring durability.
Cruise the online chat forums for flooring contractors and some are seeing red rather than green. There are stories of bamboo floors lasting mere days before they are destroyed by every day wear; contactors being asked to remove floors they installed maybe only a month or two previous. Is the wonder-grass not so wonderful after all? What are the factors that affect bamboo flooring durability?
It starts with the plant itself. Not surprisingly, the durability of a bamboo floor is somewhat dependent on the hardness of the bamboo itself. The species of bamboo, the time and method of harvest, and how it is handled post-harvest will all contribute to the quality of the bamboo.
There are approximately 1,400 species of bamboo, but it is largely those of the genus Phyllostachys that are used for commercial timber purposes.
The bamboo should be harvested when the culm (the stalk) is at its greatest strength (around 6 years old) and when sugar levels in the sap are at the lowest to avoid attracting pests. Unfortunately, the demand for bamboo is driving some growers to harvest when the plants are younger and not as strong.
This is important to know, but unless you plan on harvesting the bamboo yourself, it’s not very useful when you’re at the flooring store trying to make your selection. However, if you are serious and want to tap into your inner geek, you can purchase a handheld microscope (assuming you don’t already have one) that will allow you to look at the bamboo cells under magnification. Younger bamboo will have bigger cells in less density than older bamboo, so if you’re making comparisons, opt for the bamboo with greater cell density.
A good coat is important. Bamboo floor boards are treated with a polyurethane finish. This coating will have a significant impact on the durability of the floor. A good quality board with high durability will have 7 to 8 coats of acrylic aluminum oxide enhanced polyurethane.
You can test the quality of the coat by scratching the surface with a sharp object. If you penetrate the coating easily and scratch the wood, it is likely an inferior coating. Some coats will even dent with the press of a fingernail, which doesn’t bode well for a 200 lb dinner guest leaning back on his chair.
Also, keep in mind that a semi-gloss finish will show scratches more than a satin finish.
Solid or strand woven? Solid bamboo flooring is made from long narrow strips of bamboo pressed and glued together. A large portion of the bamboo is wasted in this process as only the best strips are used. This waste bamboo is then broken down into strands and pressed together to form what is known as strand woven bamboo flooring.
Strand woven bamboo flooring is very hard and very durable but may not be as aesthetically pleasing to some. If you opt for strand woven flooring, have a look at the cut edge of the board. If there are a number of gaps between the bamboo fibers, it likely means that it wasn’t pressed with sufficient pressure – so look for a brand with only the odd gap. You can learn more about strand woven bamboo in the following video.
Thickness is important. A solid bamboo floor board should be approximately 15mm in thickness. Those that are thicker (~18mm) may be compensating for lower quality materials.
Strand woven floor boards should be more than 14mm thick to avoid cupping in humid environments.
The Janka factor. Janka hardness is a means of quantifying the hardness of wood products. It is a measure of the resistance of various wood types to withstand density and wear. It depends on the individual bamboo product as to whether it’s harder or softer than a typical hardwood floor.
Some bamboo flooring products have been carbonized to obtain a rich dark colour. Though instinctively one might think this also adds strength and durability to the floor, this is far from true. Carbonized bamboo floors actually have a lower Janka hardness rating than natural bamboo floors.
Carbonized bamboo has a Janka hardness of 1180, while natural bamboo sits at about 1380. To put this in perspective with other woods, red oak is 1290, white oak is 1360, and hard maple is 1450. Strand woven bamboo has a Janka hardness of 3000, similar to Brazilian redwood at 3190.
Caring for your floor will increase its longevity. It goes without saying that a bamboo floor should be cared for just like any hardwood floor. Here are some tips for keeping your bamboo floor looking good for longer:
- Use area rugs in high-traffic spots
- Use cleaners that are appropriate for hardwood
- Only use slightly damp mops for cleaning as excessive water can cause damage
- Don’t use abrasive cleaning products
- Clean frequently to remove dirt and particles that can cause scratching
Bamboo flooring durability: some final environmental thoughts. There is no doubt that bamboo is an extremely renewable resource. However, there are aspects of its processing that are less than Earth friendly. Many of the glues used in preparing bamboo flooring contain formaldehyde, a highly toxic and carcinogenic chemical. Many retailers are marketing products made with formaldehyde-free glue, so be sure to ask when purchasing your floor. Also, many states are growing their own bamboo, and buying a local product will have a much smaller carbon footprint than something shipped from Asia. Finally, spending the time and money to research and purchase a quality product will ensure a durable and long lasting floor. After all, it doesn’t matter how green the resource is if you have to replace it a year or two down the road.