Traditional Architecture

The Size of Wall Molding

Conventional wall moldings are sized based on taste. There are some guidelines that will help keep your moldings in scale with one another to give it a classically”balanced” look. Most homes feature at least baseboard and window and door casings, while others have as many as four moldings on a single wall, with the inclusion of crown and chair rail. Selecting the right size may greatly impact the visual impact of your own trim.


Baseboard molding runs across the base of the wall, against the floor. Typical baseboard moldings possess a detail cut across the upper edge, with a cove, or quarter round molding at the bottom edge. Many baseboards have been 1/2 to 1 inch thick and 3 to 8 inches tall. Quantify baseboard size by its relationship to crown and casing. Baseboard is typically taller than casing is wide, and about as tall as the crownmolding. The taller the crown, the taller the baseboard must be to maintain visual balance. A conventional 8-foot wall typically includes a baseboard 3 to 5 inches tall, while a 10-foot ceiling requires 5 to 7 inches.


Casing is a horizontal molding that frames window and door openings. Casing is typically flat across the outside edge with a design that tapers toward the inside of the framework. It usually smaller than baseboard, but may be as wide as baseboard is tall. When selecting casing width, think about the contrast of your paint, or colour scheme. Greater contrast will make moldings stand out, and broader moldings may become overpowering. Since casing is as much a horizontal visual as vertical, the width is not as tied into the size of this room, although bigger rooms with higher ceilings do call for somewhat wider casing. Standard casings are to 4 1/2 inches. Older houses, such as Victorians, frequently have casing as wide as 6 inches.


Crown molding is usually in proportion to the baseboard molding. The guideline is, the taller the baseboard, the taller the crown, and vice versa. A conventional 8-foot wall could be overpowered by big ornate crown. Moldings at this height typically range between 3 and 5 inches. Taller walls up to 10 feet need bigger moldings to maintain the scale. A 10-foot wall may manage moldings between 5 and 7 inches. For taller walls, combinations of moldings may be constructed up to make a composite that is unique to that setup.

Chair Rail

Chair rails operate horizontally across the wall at about the height of the top of a normal wooden seat, or about 36 inches. They are frequently installed together with wainscot, which is a wood paneling that covers the lower third of the wall’s height. Chair rail is normally a smaller detail molding. Most seat rail ranges from 1 1/2 to 3 inches. Typically seat rail is smaller than window and door casing, and about 1/2 the size of the crown or baseboard. It tends to be somewhat thicker than the baseboard or casing, to hold seat tops out from the wall.

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