Redwood

There are over thirty different grades of redwood lumber including general purpose grades and specialized grades for a single use. There is a grade of redwood for almost any application suitable for wood. Redwood is graded by appearance and durability, with criteria defined by the Redwood Inspection Service.

Excellence of appearance is a major factor in the grading of redwood. Clearness (freedom from knots) is the determinant for the highest grades. Other grades are categorized by number, size and nature of knots and the presence of other characteristics such as stains, crook or manufacturing defects that may occur.

For durability and resistance against insects and decay-redwood is graded by its color. Reddish-brown heartwood from the inner portion of the tree contains extractives that render it resistant to decay. The cream-colored sapwood that develops in the outer growth layer of the tree does not possess the heartwood's resistance to decay and insects. As a rule of thumb, all heartwood grades of redwood will have the word "Heart" in the grade name.