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The Low-Down on Crown

Construction How-To, Decorating, Finish Carpentry, Mantels. Trim, Molding December 9, 2013 Sonia


The Basics of Installing Crown Molding

By Larry Walton

Crown molding can get type-cast in the role of decorative molding like butter-cream lattice work on a wedding cake. It’s necessary to achieve a certain look, but not necessarily functional.

However, start looking for the crown around you and you will begin to see its many functions. For one thing, that ubiquitous wall-to-ceiling crown creates a transition that softens the harsh angle and hides irregularities. It make the problems associated with that particular corner go away.

Crown also serves as a corbel to support cantilevers in many structures such as mantel tops and plant shelves. It functions much like a knee brace to provide vertical support for horizontal planes.

When it comes to interior finish carpentry jobs, the level of a project can almost be measured in terms of the amount of crown molding involved. Big projects often involve ceiling crown in every room and on every door and window header. Cabinets are topped with crown, open landings are girded with crown and mantel tops are supported by crown. Crown is often used as an apron for window stools.

Having said all that, one of the best ways to get started working with crown molding is topping a simple rectangular room.

Crown molding should be proportionate to the room. I recently installed crown in a house with only 7-1/2 ft. ceilings but it worked quite well because we used a very small 2-1/4-in. crown molding, which was just right for the application. Larger rooms with high ceilings can and should take a larger crown molding. For example, 4-1/2-in. crown is common for rooms with 9-ft. ceilings.

Crown is available in lots of different profiles. Some designers add extra trim details to the crown design by installing an extra piece of flat trim on the ceiling and/or the wall to add detail and strengthen the feel of the crown. Some crown designs have space to add dentil molding while others have a built-in dentil detail, but the most common profiles are one piece with a large cove in the face and an extra ogee detail, which belongs at the bottom. I teach my crew to remember “detail down,” which means the part with the most contour goes down or along the wall.

Pre-paint or pre-stain the crown and allow it to dry.

Pre-paint or pre-stain the crown and allow it to dry.

An important concept to understand when installing crown molding is that it must be oriented properly for the connections to work out. Crown molding is designed to transition between the wall and the ceiling at a specific angle. Because there is a void behind the molding, this angle is not always obvious and not always easily maintained during installation. To maintain the proper angle, which is essential for tight fits and proper joints, install the crown at a consistent distance from the ceiling at the point where it touches the wall.

Read the scale on the framing square for the amount of wall and ceiling that is covered by the crown.

Read the scale on the framing square for the amount of wall and ceiling that is covered by the crown.

Start by measuring the room to get the linear footage needed to go around the perimeter of the room. Preferably, you will get the crown in lengths that can be installed without splicing. Buy at least 1/2-ft. extra for each wall.

Measure the vertical and horizontal positioning of your crown molding. Using a framing square to mimic the ceiling and wall, position a short piece of crown so the ceiling and wall surface are flat on the tongue and the blade of the framing square. Read the scale on the framing square for the amount of wall and ceiling that is covered by the crown.

Large crown molding profiles leave a gap at the rear that is too large to be spanned by a finish nail.

Large crown molding profiles leave a gap at the rear that is too large to be spanned by a finish nail.