Threshold

adjustable exterior door threshold

Threshold – The lower most horizontal part of an exterior door unit. The threshold is attached to the bottom of the door jamb where it maintains the proper width of the jamb and also provides a seal against the bottom of the door when closed. Most modern thresholds consist of an aluminum frame with a vinyl or composite spacer inset in the bottom and plastic or wood strip inset into the top that can be adjusted to fit the bottom of the door.

Interior thresholds are usually made of wood, stone, tile or composite materials. They are cut to fit between the door jambs and serve to provide both a break point for finished floors of dissimilar heights or materials, and to serve as finish molding to conceal the space where the floors meet in the doorway.