The Process of Fuming Oak Flooring with Ammonia

Fuming is a traditional wood treatment process that enhances the natural tones of oak flooring by darkening the wood without the use of stains or dyes. This is achieved by exposing the oak to ammonia fumes in a controlled chamber. The result is a rich, deep color that varies depending on the concentration of ammonia and the duration of exposure.

How Does the Fuming Process Work?

1. Placing the Oak in a Sealed Chamber

   The oak planks are arranged inside an airtight chamber, ensuring even exposure to ammonia fumes.

2. Introducing Ammonia Vapors

   Ammonia is introduced into the chamber in controlled quantities. The ammonia reacts with the tannins present in the oak, causing the wood to darken naturally. The higher the tannin content, the more intense the color change.

3. Timing and Ammonia Concentration

   • Light fuming: 12-24 hours – Produces a mild, natural tone shift.

   • Medium fuming: 24-48 hours – Deepens the color further, adding richer brown hues.

   • Heavy fuming: 48-72 hours – Results in an intense darkened effect, often resembling aged or smoked oak.

   • The quantity of ammonia also plays a role; higher concentrations will lead to a darker finish in a shorter amount of time.

What Is Core Fuming?

In standard fuming, the ammonia reaction occurs primarily on the surface of the veneer, meaning deep scratches may reveal the lighter wood beneath. However, core fuming is a more intensive process where the ammonia penetrates all the way through the entire thickness of the veneer.

Benefits of Core Fumed Oak Flooring

• Consistent Color Throughout – Since the darkened effect goes all the way through the veneer, any scratches or wear will not reveal a lighter color beneath. Instead, a simple application of oil or maintenance treatment will restore the original shade seamlessly.

• Longer Lifespan – With color running deeper into the wood, core-fumed oak flooring maintains its appearance longer, reducing the need for refinishing.

• Natural Aging Appeal – Unlike stained flooring that may wear unevenly, fumed oak develops a beautifully aged look over time while maintaining its rich, deep color.

Final Thoughts

Fuming oak flooring with ammonia is a time-honored technique that enhances the natural beauty of wood while providing long-lasting, deep coloration. Whether opting for surface fuming or full core fuming, this process ensures a luxurious and authentic appearance that cannot be replicated with traditional staining. If durability and timeless beauty are priorities for your flooring, core-fumed oak is an excellent investment.