A dado is a rectangular groove cut into wood to receive another piece, creating a strong, precise joint in construction and woodworking.

A dado is a flat-bottomed, rectangular groove cut across the grain or along the length of a wood member to receive another piece of material. Commonly used in carpentry, millwork, and finish construction, dados create strong, flush joints that improve alignment and load distribution between connected components.

In construction applications, dados are frequently used in cabinetry, shelving, wall panel systems, and built-in furniture. By allowing one board to nest securely into another, a dado joint increases surface contact, which enhances structural strength compared to simple butt joints. Dados are typically cut using table saws, routers, or specialized dado blades.

From a performance standpoint, dado joints provide consistency, accuracy, and durability in both residential and commercial projects. They are especially valuable where repeated loads or precise alignment are required, such as in casework or architectural millwork. Proper sizing, depth control, and material selection are essential to ensure a tight fit and long-term stability.

The term “dado” comes from architectural language, where it originally referred to the lower section of a wall beneath the chair rail.