Bamboo Floor - Manufacture

Manufacture

Different forms of bamboo flooring exist. Each varies in its manufacturing process and differs largely based on economic viability and local preferences.

The most common form, particularly in southeast Asia, uses thin bamboo stems that are cut as flat as possible. They are cut to similar lengths and can be stained, varnished, or simply used as is. They are then nailed down to wooden beams or bigger pieces of bamboo stems. This form results in more space between each bamboo stem; flatness and tightness is not emphasized. This technique is usually used on stilted houses, resulting in better air circulation especially during the warmer summer months.

The manufactured bamboo flooring commonly found in North American markets is highly processed. Bamboo flooring is typically made by slicing mature bamboo poles or culms into strips. These culms are crosscut to length and then sliced into strips depending on the width desired. The outer skin and nodes are removed. To remove starch and sugars the strips of bamboo are boiled in a solution of boric acid or lime. The bamboo is then dried and planed. Natural bamboo color is similar to beech wood. If a darker color similar to oak is desired, the bamboo goes through a carbonizing process of steaming under controlled pressure and heat. The carbonizing process can reduce the floor's final hardness significantly compared to non-carbonized bamboo, rendering it softer than some pines and softer than more common red oak.

Most bamboo flooring uses a urea-formaldehyde (UF) adhesive in the lamination process. Though the use of UF resins, which emit volatile organic compounds (VOCs), is harmful to indoor air quality, bamboo flooring uses a relatively small amount compared with other materials, such as particleboards. Bamboo flooring products that avoid formaldehyde use are available, including some listed in the GreenSpec Directory. The panels are then heat pressed to cure the adhesive. The cured boards are then planed, sanded, and milled. Finally an ultraviolet curing lacquer is applied to the boards.

Manufactured bamboo floors are typically made available in planks with either vertical- or horizontal-grain orientation. In vertical bamboo floors, the component pieces are stood vertically on their narrowest edge and then press laminated side to side. The effect is a lined, almost uniform look to the surface of the finished floor plank. In horizontal bamboo floors, the slats are arranged in a horizontal direction, on their widest edge, and then joined side by side with adjacent pieces using a high-pressure laminate system. The characteristic nodes of the bamboo are visible on the finished horizontal surface.

Locking bamboo flooring is the easiest to install. Individual flooring planks have interlocking joints that click precisely into place. By combining plank alignment and color a lot of different styles can be produced.