A rough brick arch is a type of masonry arch constructed using ordinary, uncut bricks, where its distinctive curved shape is achieved by varying the thickness of the mortar joints rather than by shaping individual bricks.
Understanding Rough Brick Arches
Rough brick arches represent a more straightforward and often more economical method of creating an arched opening in brickwork. Unlike finely crafted arches that employ precisely cut bricks, known as voussoirs, rough brick arches utilize standard building bricks as they are.
Construction Method
The defining characteristic of a rough brick arch lies in its unique construction technique:
- Ordinary Bricks: It is built using standard, rectangular bricks that are not specially manufactured or shaped for the arch.
- No Cutting: Crucially, the bricks are not cut to form wedge-shaped voussoirs. This distinguishes them from more refined arch types.
- Wedge-Shaped Joints: The arch's curve is provided by forming wedge-shaped mortar joints between the bricks.
- The mortar is applied with greater thickness at the extrados (the outer, upper curve of the arch).
- The mortar is applied with smaller thickness at the intrados (the inner, lower curve of the arch).
This variation in joint thickness compensates for the uniform shape of the bricks, allowing them to collectively form a curved structure.
Appearance and Application
The reliance on varied mortar thickness for its form gives a rough brick arch a specific aesthetic and dictates its common uses:
- Unattractive Appearance: Due to the irregular and varying thickness of the mortar joints, rough brick arches often look unrefined and are generally considered unattractive.
- Limited Exposure: Consequently, these arches are not recommended for exposed brickwork. They are best suited for applications where the arch will be hidden or covered by other finishes.
Key Characteristics Summarized
Here’s a quick overview of the defining features of a rough brick arch:
| Characteristic | Description |
|---|---|
| Brick Type | Ordinary, standard bricks. |
| Brick Shaping | Bricks are not cut or shaped into voussoirs. |
| Curve Formation | Achieved by forming wedge-shaped mortar joints. |
| Joint Thickness | Greater thickness at the extrados (outer curve), progressively smaller thickness at the intrados (inner curve). |
| Aesthetics | Often looks unattractive due to the varying and irregular mortar joint thickness. |
| Application | Not recommended for visible or exposed brickwork; ideal for hidden, utilitarian, or subsequently finished applications. |
When Are Rough Brick Arches Used?
Rough brick arches find their practical application in scenarios where aesthetics are secondary to structural function or cost-efficiency:
- Hidden Openings: They are commonly used above openings that will be plastered, rendered, or otherwise covered, such as internal doorways or windows where the arch is simply a structural element.
- Budget Constraints: When project budgets prioritize lower material and labor costs, avoiding the expense of cutting bricks can be a significant advantage.
- Utilitarian Structures: In buildings or areas where the primary concern is structural integrity over fine architectural detail, such as in foundations, cellars, or industrial settings.
Contrasting with Other Brick Arches
It's useful to understand rough brick arches in contrast to more refined types:
- Rough Brick Arch: Uses uncut, ordinary bricks with varying, wedge-shaped mortar joints. The finish is typically coarse.
- Gauged or Cut Brick Arch: Employs bricks that are precisely cut or molded into perfect wedge shapes (voussoirs). This allows for very thin, uniform mortar joints, creating a highly aesthetic and precise finish, often seen in heritage architecture. For more details on various arch construction methods, explore resources on masonry arch construction.
In essence, a rough brick arch serves as a functional and economical solution for bridging openings in masonry, particularly where its appearance will not be a prominent feature.
