Bamboo flooring has earned its place as a sustainable and stylish alternative to hardwood, but when it comes to choosing between natural and carbonized bamboo, there's more to consider than color. As a flooring factory technologist, I've worked closely with teams in harvesting, manufacturing, and quality control, and I've seen how these two options differ not just in appearance, but also in durability, processing, and chemical performance.

This isn't a matter of which is better—it's about understanding how each type is made, how it performs under pressure, and what goes into ensuring it meets quality and environmental standards.

Bamboo Harvesting: Setting the Stage for Color and Strength

All bamboo flooring starts with one critical input: Moso bamboo, primarily grown in China. The age of the bamboo at harvest impacts both strength and flexibility. For flooring, the ideal harvest age is 5 to 6 years. Younger bamboo lacks density, while older culms can become brittle.

Once harvested, the bamboo culms are de-limbed, split, and milled into strips. At this point, the decision is made: will the bamboo remain natural in color, or undergo carbonization?

What Is Natural Bamboo Flooring?

Appearance:

Natural bamboo retains its original light yellow-blonde tone. The grain and nodes are more visible, giving it an organic, airy look that works well in Scandinavian, minimalist, or coastal interiors.

Manufacturing:

After the culms are split and boiled to remove starches and sugars (which prevent insect infestation), the bamboo strips are kiln-dried and then pressed into flooring planks using one of three methods:

  • Horizontal
  • Vertical
  • Strand-woven

No heat treatment is applied beyond standard drying, so the natural lignin and cellulose structure remains intact, preserving the bamboo's maximum hardness.

What Is Carbonized Bamboo Flooring?

Appearance:

Carbonized bamboo has a richer, darker tone—ranging from honey brown to deep amber. This is achieved through a high-temperature steam treatment that caramelizes the sugars within the bamboo fibers.

Manufacturing:

After boiling and drying, the strips undergo a carbonization process—typically in a pressurized steam chamber. The high heat (around 200°C or 392°F) causes a chemical change, darkening the bamboo internally. The strips are then glued and pressed the same way as natural bamboo.

Performance Differences: Hardness, Stability, and Wear

1. Hardness

  • Natural bamboo is harder than carbonized bamboo.
  • Carbonization reduces the bamboo's density by around 10–20% due to fiber softening.
  • In strand-woven versions, this difference is less pronounced because the manufacturing process compensates with resin pressure.

Janka Hardness Ratings (approximate):

  • Natural Strand-Woven: 3000+
  • Carbonized Strand-Woven: 2800–3000
  • Natural Vertical/Horizontal: 1300–1400
  • Carbonized Vertical/Horizontal: 1100–1200

2. Dimensional Stability

Both types are dimensionally stable when properly manufactured and acclimated. However, carbonized bamboo may be slightly more prone to expansion and contraction due to the structural changes caused by heat treatment.

3. Scratch and Dent Resistance

Natural bamboo resists denting better in horizontal and vertical styles. In strand-woven flooring, the difference is minor, with surface coating playing a bigger role in scratch resistance.

Glue and Resin: What Holds It Together?

Regardless of color, bamboo flooring uses industrial adhesives to bond strips or strands together. Here's what we use in the factory:

  • UF (urea-formaldehyde): Common in lower-cost flooring, but many manufacturers now offer low-formaldehyde or formaldehyde-free options.
  • Phenol-formaldehyde or modified resins: Used in strand-woven bamboo for better water resistance and bond strength.

Emission Standards to Look For:

  • CARB Phase 2 (California Air Resources Board)
  • EPA TSCA Title VI
  • E0 or E1 (European standards)

Natural and carbonized bamboo can both meet these standards if the right adhesives are used. Always request third-party formaldehyde emission test reports when sourcing flooring.

Lacquer and Finish: Protecting the Surface

Both natural and carbonized bamboo are finished using multi-layer UV-cured polyurethane or acrylic lacquers. These coatings protect the surface from wear, moisture, and scratches.

High-quality bamboo flooring usually includes:

  • 5–7 coats of UV-hardened lacquer
  • Optional aluminum oxide for additional abrasion resistance
  • Surface options: matte, satin, semi-gloss

The carbonization process can slightly reduce how deeply the lacquer penetrates, so proper sanding and sealing during manufacturing is critical.

Quality Control: Maintaining Consistency and Safety

In the factory, quality control protocols are applied equally to both natural and carbonized bamboo. Here's what we monitor:

  • Moisture content: Target is 6–9%. Too high leads to warping; too low causes brittleness.
  • Dimensional tolerance: CNC milling ensures click-lock or tongue-and-groove systems fit perfectly.
  • Color consistency: Especially important for carbonized bamboo, which can vary based on exact steam treatment time and temperature.
  • Bond strength: Tested using shear and delamination tests.
  • Surface hardness and finish adhesion: Evaluated using Taber abrasion tests and impact resistance.

Which One Should You Choose?

Go with natural bamboo flooring if:

  • You prefer a light, clean aesthetic.
  • You want the hardest possible floor.
  • You're installing in high-traffic areas like kitchens and hallways.

Choose carbonized bamboo if:

  • You love warm, darker tones that resemble walnut or teak.
  • You want a cozy, elegant look for bedrooms or living areas.
  • You're not overly concerned with maximum hardness.

Both natural and carbonized bamboo can be manufactured to high standards, but understanding their differences will help you choose the one that fits both your design and performance needs.

As someone deeply involved in the flooring manufacturing process, I can say that the best outcomes come when design expectations are matched with technical realities. Whether you're buying or specifying flooring for a project, knowing how it's made gives you an edge.