Master Class in Moldings
An illustrated guide to the profiles and proper proportions of baseboard, crown, and casing.
Have you ever flipped (or scrolled) through the pages of a molding catalog and been overwhelmed by the options? If so, you are not alone. And while you may be daunted by the number of options, the fact is that typically only the smallest percentage, sometimes only a dozen or so out of hundreds of profiles, are architecturally correct. Historically, the purpose of a molding was to cover joints and transitions between materials. Over time, the functional needs evolved to become decorative and adapted to different architectural styles and periods, which has only added to the variables. Yet, with a basic understanding of the building blocks that make up molding profiles and their uses, you’ll be able to navigate catalogs and lumber yards and select moldings to compose trim packages for any home.
While at a glance, moldings may appear to be a random combination of profiles—and unfortunately, in many modern applications, they are in fact no more than a mishmash of curves—even the most complex molding designs can be broken down into four simple building blocks.
The building blocks generate moldings of all shapes and sizes that can be assembled in an infinite number of configurations for uses on nearly every surface of a home, both inside and out. Yet, despite the endless variables, molding profiles can be broken down into four primary categories defined by the job the molding is performing. These categories are terminating, supporting, separating, and translating.
Baseboards cover the transition between the flooring and the walls. The base cap is a translating molding, or a molding that shifts between two planes—in this case, the flat top edge of the baseboard and the wall. The baseboard does not need a base cap; if stock profiles are limited or you want a more streamlined look, use a flat-stock molding throughout the house. If you are adding profiles to your flat stock, consider these rules.
While crown moldings are technically in a supporting position holding up the ceiling, because they are located at the top of the interior walls, they have evolved over time to be terminating moldings. Before selecting a crown molding, ask yourself if this is an element that you really need in the house. Unlike baseboard and casing, which bridge between different materials, the walls and the ceiling are typically the same material, so a connection for practical reasons is not necessary. Crown moldings are generally an aesthetic element.
Window and door casings
Window and door casings follow many of the same rules of thumb as baseboard. The building blocks of casing are a flat-stock member with detail added in two areas: the backband and the transition to the jamb.
For more information, check out this related article: Make the Most of Moldings
For illustrated details on all these topics and more, click the View PDF button below.