Torrefied Wood Doors

Whether you are replacing an old door, or just buying a new one, it is important to consider all your options. In addition to the traditional types of wooden doors on the market, a new kind of door is rising in popularity, and for good reason: the torrefied wood door.

Torrefied fir door in a fir jamb (Photo by Wenes Negreli / Elite Company)

Torrefied fir door in a fir jamb (Photo by Wenes Negreli / Elite Company)

What is a torrefied door?

The definition of torrefy is simply to dry or roast with fire. That’s exactly what torrefied wood is: wood that has been heated over a long period of time within a controlled atmosphere. Another term commonly used to describe wood that has been treated this way is thermally modified.

This process improves the durability and stability of the wood’s structure. Additionally, the exposure to extremely high heat removes organic compounds from wood cells. This minimizes the wood’s tendency to rot, since there are no longer any organic sugars to decompose or for insects to feed on.

Torrefied wood is also much more resistant to potential damage from harsh weather conditions including heat, cold, and moisture, since the wood does not absorb water that would cause it to expand, contract, or warp. Along with doors, torrefied wood is often used for hardwood flooring or outdoor decks.

How does the torrefaction process work?

The superheating process involves cooking the wood in a controlled environment under extremely high heats, between 400 and 600 degrees Fahrenheit. The environment is oxygen starved to prevent the wood from burning. Additionally, torrefaction is an all-natural, chemical-free process, leaving no toxic residue behind.

The process takes roughly 24 hours, depending on the species and thickness of the wood. The most commonly used wood species include poplar, ash, red oak, and soft maple, according to Scott Seyler of Northland Forest Products, a BBR supplier. The finished door is solid wood (as opposed to other doors that have veneer over an inner core), making for a very strong composition.

Torrefied wood can be either stained or painted to achieve a desired color. Leaving the wood unfinished results in a grey tint brought on by ultraviolet exposure over time, which can be prevented by staining.

Wood torrefaction as we know it today is a relatively new invention. Modern thermal modification technology has only been around for about fifteen years and has become increasingly popular in recent years. However, the Japanese have been performing a similar wood treatment method known as yakisugi or shou sugi ban for centuries in order to achieve the same properties of water and rot resistance. This traditional method of preserving wood involves charring it with fire and then coating it in natural oils.

Why purchase a torrefied wood door over regular wood?

The heating process makes a torrefied wood door much more resistant to the elements, all while maintaining that beautiful natural wooden aesthetic that so many homeowners desire. Especially in Boston, with its sometimes harsh weather conditions, a torrefied door would stand the test of time.

The biggest drawback to a torrefied value is the cost, which can be 50% to 100% more than a traditional wooden door. While this is understandable considering the overall higher quality and durability, some homeowners may choose a fiberglass door—a much cheaper alternative that is just as weather resistant, but with a very different appearance.

While torrefied doors are rather expensive, they usually have a warranty up to 20 years, and they can be installed in areas without an overhang, unlike other wood doors. BBR customers have reported satisfaction with torrefied door purchases.

Kathleen McColgan

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