What is a Plynth Block?
Definition of Plynth Block in Construction
A transition piece of trim molding that is installed at the intersection of the jamb, head and sill trim of a door, window or other opening in the project.
In many cases the plynth block is an architectural piece, that will have either a carving or decorations on the surface. The installation of a plynth block, allows the corresponding adjacent trim pieces to butt into the plynth block, without the need for a sophisticated miter joint at the intersection. The plynth block was used extensively in period homes constructed during the middle of the 20th century as well as colonial style homes with probably the most famous decoration a pineapple on the surface.