How to Identify Chestnut Lumber

Before the 20th century, American chestnut (Castanea dentata) was a favored wood for furniture and flooring. The trees were largely wiped out by Asian bark fungus (Cryphonectria parasitica) in the early 1900s, so the wood now is rare and valuable; the biggest source is from salvaging old buildings.

Chestnut wood is easy to work with hand and machine tools. It splits easily, so care must be taken when nailing or using screws. Wormy chestnut, formed when insects invaded the fungi-damaged trees, has holes and discolorations that make it even more valuable for rustic applications.

The wood nearest the core, called heartwood, is light to medium brown; it darkens to reddish or chocolate brown with age. Newer wood is white to light brown. It has a coarse texture and is resistant to insects and diseases.

Chestnut is often confused with white oak because both woods are ring-porous. They have bands of large, circular cells parallel to the bark, which can be seen on the end grain, or cross-section. A piece of chestnut lumber, however, will be lighter in weight than a comparable piece of oak lumber.

A sure-fire method for telling chestnut and oak apart is to look for rays – straight bands of tissue – running perpendicular to the growth rings. Oak has broad bands, while chestnut has none. Looking at the end grain will reveal the rays.