Horizontal bamboo is in it's natural state. which is stronger than carbonized, but weaker, far weaker in-fact than woven or stranded bamboo.
"Horizontal" refers to the way in which the grass is laid out before it is formed into boards. With horizontal bamboo you will see the true characteristics of bamboo, because it is laid horizontally along, what will become the length of the board, so you will see it's knots along its length.
Vertical bamboo flooring shares the same natural state as horizontal bamboo. The difference is only the way in which the grass is laid out prior to board formation. The end result is, with vertical bamboo you will not notice the same knot formation.
The name Carbonized bamboo provides the product with a misleading conception. We think of Carbon, we think of strength and durability.
But in-fact all that the carbonizing process does regarding bamboo flooring is simply give the bamboo a darker and more elegant richer colour. Carbonized bamboo is typically a nail/staple down flooring.
Carbonized bamboo is the weakest of the four types of bamboo flooring.
Strand Woven bamboo
Strand Woven bamboo is the process of adhering bamboo grass fibers together, much like its three cousins horizontal, vertical and carbonized bamboo flooring. The difference is the woven process. This makes the finished product much stronger. Very similar to South American hardwoods in-fact. Such as Jatoba (Brazilian Cherry) and Tigerwood.
The visual characteristics of Strand Woven Bamboo Flooring strays away for the traditional look of the other three type's of Bamboo above. Strand Woven Bamboo Flooring looks much like a low grain Hardwood such as Hard Maple. Strand Woven bamboo flooring is incredibly durable.