knot

wood

Written by

The Information Architects of Encyclopaedia Britannica

Last updated

June 30, 2026

Quick Summary

A knot in wood is a defect caused by the inclusion of dead or living branches within the tree's structure. These knots are largely unavoidable but can be minimized through silvicultural practices like pruning. The presence and type of knots can negatively impact the wood's appearance, strength, and stability. A "sound knot" is one that is as hard as the surrounding wood and free from decay, remaining firmly in place. Wood itself is a versatile material with desirable qualities like strength for its weight and workability, but it also has drawbacks such as susceptibility to burning and decay. Its hygroscopic nature means it absorbs and releases moisture, causing dimensional changes.123

Summary created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

5 Britannica Sources

Ask Britannica AI about this topic

Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.

wood
Variation of structure and defects
…presence of defects such as knots, spiral grain, compression and tension wood, shakes, and pitch pockets. Knots are caused by inclusion of dead or living branches. Because branches are indispensable members of a living tree, knots are largely unavoidable, but they can be reduced by silvicultural means, such as spacing…
Read More
…presence of defects such as knots, spiral grain, compression and tension wood, shakes, and pitch pockets. Knots are caused by inclusion of dead or living branches. Because branches are indispensable members of a living tree, knots are largely unavoidable, but they can be reduced by silvicultural means, such as spacing…
Read More