Illustrated Architecture Dictionary............... Illustrated FURNITURE Glossary
(DADE oh) (plural dados or dadoes)
The part of a wall below the dado rail (chair rail), sometimes decorated with paneling or wainscoting.
Purpose of the dado, historically, was to cover the lower part of the wall which was subject to stains from rising damp.
Dado rail / chair rail: A horizontal moulding fixed to an interior wall about 4-5 feet above the floor. Purpose of the dado rail (chair rail) was to protect the wall from chair backs.
Examples from Buffalo: