MOULDINGS IV - THE CAVETTO

The cavetto (also known as the hollow or cove) is the concave counterpart of the convex ovolo: both take the form of a quarter-circle arc. But where the projecting mass of the ovolo conveys sturdiness and loadbearing ability, the hollowed-out cavetto is used to express delicacy and lightness, in particular as a crowning moulding (shown above) for ‘topping off’ a building, allowing it to ‘feather out’ at its highest point.

The shadow gradient of the cavetto is the reverse of the ovolo, being darker at the top and lighter at the bottom.  With the sun at 45°, the upper part of a downward-facing cavetto is about ½ shaded, transitioning smoothly to fully lit at the bottom.  The thin, fully-lit fillet that sits on the cavetto in the crowning moulding contrasts with the shaded upper part to bring a sharp definition to the feathered edge of the building.

Whether facing down or up, the cavetto also provides a simple and elegant way of transitioning from a vertical to a horizontal surface; it is still commonly seen in this role, as a plaster cornice covering the joint between wall and ceiling in many contemporary houses. 

BRICK CHIMNEYS

Traditionally, brick chimneys bricklayers a chance to show off their skills and creativity, without being too showy about it: chimneys are prominent on the building silhouette and visible from the street, but only if you make the effort to look up. Brick chimneys and fireplaces have almost disappeared from new house builds, reflecting the change over the years from coal or wood heating to gas and now split systems. Where new houses have chimneys at all, they are much more likely to be a simple steel pipe with a cowl, connected to a freestanding woodburning stove. But even before this transformation, the Great Scold modernism had stripped the ornament from chimneys as it had from all brickwork, and by the 1960s and 70s most brick chimneys were simple undecorated cuboids.

Who would be a bricklayer today? Nothing but course after course of stretcher bond veneer, with the occasional soldier course over a lintel if you’re lucky. Predictably, modern architects show almost no interest in the endless possibilities presented by the traditional language of brick masonry: bonds, cornices, string courses, arches, colour patterns, ‘special bricks’. Instead there is only stretcher bond, or at the other extreme, attention-seeking gimmicks such as incorporating text into the wall, or Frank Gehry-style ‘parametric’ brickwork- in its way just as mechanical and monotonous as stretcher bond, but somehow supposedly ‘clever’.

Below are a few photos of brick chimneys from the 19th and early 20th centuries, all taken within an area of a few blocks. They range from barely ornamented examples on weatherboard workers’ cottages to more elaborate displays featuring multiple colours and special brick shapes. As is typical of vernacular architecture, they are all more or less the same, and at the same time all different.

MOULDINGS III - THE OVOLO

The ovolo is the simplest of the convex mouldings: its profile is a simple arc, usually of 90 degrees.  The uniform change in angle produces a correspondingly smooth shadow gradient: whether the ovolo faces up or down, the shadow transitions from light at the top to dark at the bottom. 

The convex ‘bulge' of the ovolo gives it a robust, dependable character; whether supporting a cornice or sitting at the base of a column or wall, it expresses a sense of resistance to gravity and muscular deformation under load.

Like the fillet and the fascia, the ovolo is still in common use, chiefly as the small timber moulding known as a quad, which is used to cover joints at 90 degree changes of angle such as that between a external brickwork and the eaves soffit, between a wall and kitchen cabinets, or as cheap skirtings or cornices in utilitarian rooms like toilets or laundries.

MOULDINGS II - THE FILLET & THE FASCIA

After the previous introductory post on mouldings, this and the next several posts in this series will examine the various basic moulding profiles, their uses and effects.

Moulding profiles can be grouped into four general categories: flat, convex, concave, and compound. The fillet and the fascia are the only common flat mouldings; they both present a flat vertical face that may be either raised forward of the supporting wall or sunk into it (then also sometimes called a channel). The distinction between a fillet and a fascia is only one of proportion: the height of the fillet face is typically equal to or only slightly greater than its projection/recess, whereas the fascia is much taller in relation to its projection.

These mouldings produce very sharp shadows. The shadow produced by a sunk fillet is ‘in’ the fillet itself, and is more intense than the shadow produced by a raised fillet, which appears below it. In this case the height of the shadow line varies in proportion to the depth of the fillet projection.

The lighting effects produced by fillets can be modulated in several ways: tilting the face back slightly makes it lighter than the background plane; tilting it forwards darkens the face relative to the plane. Rounding or bevelling the edges of the fillet softens the shading transition at these edges. The top surface of a raised fillet and the bottom surface of a sunk fillet may be given a slight fall, to better shed water and prevent accumulation of dirt.

In classical architecture, fillets and fascia are almost never used in isolation but as auxilliary elements that function to punctuate moulding compositions and define their edges, delineate curves, and give ‘spine’ to the overall composition. When used alone, they can have a stark effect; the sunk fillet in particular was employed to this end by modernists such as Mies to delineate elevator doors and the like.

Though the more complex curved and compound mouldings have mostly fallen out of favour, being perceived as too ornate, too costly or too ‘old-fashioned,' the fascia and the fillet are still in common use, thanks to their simplicity and utility.  The fascia in particular is mostly known today as the timber board used to protect the end grain of projecting rafters and support the eaves gutter, and as the simplest profile of skirting board and architrave.  

Skirting board with fascia profile

Architrave with fascia profile

DOODLES

PLAYING AROUND with some ideas for what could be a formal gate, entry porch, garden pavilion, or the like. The process of trying to ‘freeze’ the essence of a freehand sketch into a measured drawing is always a challenge. Sometimes the essence is lost, sometimes you end up with something completely different. Here the proportions of the measured drawings have ended up squatter than the original sketch, and the curve of the arched entry is more regular, but somehow less ‘alive’.

MOULDINGS I - AN INTRODUCTION

TRADITIONAL BUILDINGS ARE articulate: composed according to an established grammar of parts and joints to form a coherent, hierarchical whole.  One particular characteristic that sets traditional architecture apart from modern, and by which traditional buildings express their articulated nature, is the use of ornamental mouldings: profiles formed in timber, stone or plaster which, when applied according to well-established rules, function to relate the parts of the building to one another through effects of light and shadow. 

From the early 20th century, modern architects, committed to the twin ideologies of social and technological progress, began to reject the ornamental tradition. After a century or more of this process of stripping away, buildings are now for the most part inarticulate, in both senses of the word: they don't have a grammar, and they don't have joints. 

The art of ornamental moulding is no longer taught in architecture schools, but could easily be revived.  There are only a handful of basic moulding profiles, and the rules of thumb governing their use can be found in old textbooks such as this one.

This post will be the first in an irregular series exploring the basic moulding profiles and how they are used, in the hope that it might be of some use to anyone interested in the topic or looking to use mouldings in their own work. Enjoy!

Example illustration from the book ”The Theory of Mouldings” by C. Howard Walker, 1926, linked above.

Hello

This blog will be a place to store and share my thoughts, opinions, ideas and inspirations relating mainly to traditional architecture and design, in particular vernacular architecture, but probably straying into other areas too. I will try to post at least once a week, on a more or less regular schedule…

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