Facing Brick: A Classification

Anyone who chooses facing brick to finish a house faces quite a lot of trouble in today's building-materials market — the choice is simply too vast. But the opportunities are vast as well: a brick wall can give a building a brutal, a romantic, or an ethnic look. The only thing left is to choose the right finishing material.

First of all, we have to understand that in today's construction there are two kingdoms — common brick and facing brick.

Common brick is used to build the body of the wall, while facing brick is used to finish its outer surface. We discuss common brick separately. Here we cover the brick characteristics that matter for facing the walls of a house.

Types of facing brick

There are many formats of facing brick. There are three simple explanations for this.

• Several brick "powers," where fired clay bricks historically had their own standard sizes (England, Belgium, Denmark, Germany, Norway), from which various multiples and variations developed.
• The desire to save money — a facing brick does not have to be full-size; it can be cut in all sorts of ways, since we usually see only the stretcher face of a brick.
• The thirst for originality — "strange" formats invented for a special request.

For completeness, we (the Archi.capital team) have compiled a large summary table from various sources. First the popular formats, and then the exotic ones.

The ratio between the sides of a brick is determined by the need to join the stones in various parts of the wall ("masonry bond" or "bonding of the joints"). Even facing bricks are often laid vertically, on end, for a decorative effect around openings.

The downside of slim bricks is that they cannot be used to build tall "unbonded" walls (on flexible ties). For example, if you want to clad a wall with a ventilation gap two stories high, use a full-size brick. In a thin brick, the flexible ties are less likely to hold, and wind loads can cause the wall to loosen. For "bonded" finishes, where the face bricks are securely bonded with mortar to the supporting wall, you can use stones of any thickness.

Shaped and Molded Bricks

Shaped brick is a type of brick with an angular, semi-circular, or U-shaped profile. Shaped brick serves both a decorative and a structural function. Today such bricks are used to decorate fences and memorial buildings. On houses they look a little mannered, out of step with the times. But they can be used in window openings, cornices, parapets, and columns, and to lay out three-dimensional ornaments. Molded bricks are made to order for exclusive projects.

Texture of facing brick

Textured or embossed brick is a type with a non-uniform surface. It may be fully or partially textured on the stretcher and header faces.

In modern production, the mixing and pressing are made so uniform that bricks can be formed by extrusion. The raw material is pushed through an opening to produce a long "sausage" — a brick bar, which is then cut into pieces. The result is stones with regular geometry and smooth sides.

But you cannot get a relief surface by extrusion. So you must either apply a decorative layer to the brick (partially textured) or make the bricks the old way — each stone molded separately. This method is called "hand-forming" to make it more appealing to the customer. In reality, there are different degrees of automation.

Both in the past and today, several rough stones are shaped at a time using a forming frame. A lump of raw material (a mixture of clay, sand, and water) is rolled in fine sand and dropped into the blind cells. The protruding part of the mass is cut off with a wire string. The mold is then turned over to release the bricks.

Because the mixture is loose, without compaction, and the frame is not cleaned before forming, the bricks come out off-size, rounded, with a rough surface and inclusions. During further drying and firing, the blanks continue to deform.

It is precisely these "low-quality" bricks that we now want most for finishing, which is why we reproduce the handicraft process in modern production.

Batch bricks with handmade relief look very interesting. They can carry ornaments or the manufacturer's branding. They can be used selectively to create subtle accents in the masonry.

Not every type of brick can be used to finish a building's facade.

Fireclay (refractory) brick withstands high temperatures perfectly but holds up poorly to moisture and freezing — facing masonry made from it is not permitted. Refractory ceramics from rare clay varieties have excellent strength and performance characteristics, but their cost is 20%–30% higher than that of clinker bricks of similar size.

So what gives the best value for money when finishing facades?

Good fired bricks — ceramic and clinker: they have the right strength, frost resistance, and thermal conductivity, are quite affordable, and leave plenty of room for decorative masonry.

Unfired bricks (silicate, hyperpressed, concrete) are good for textured masonry (for example, rough stone) and often come in a wide range of colors, but they require additional spending to protect and maintain the finished surface.

Clinker Brick

Clinker brick — a ceramic building material made from clay by firing the raw material to full sintering — is extremely strong and durable and has very high resistance to wear. It has virtually no limits on texture and color, can imitate an antique surface, and can preserve the effect of firing, which makes it highly attractive and in demand across a variety of construction fields.

In common usage, the word "clinker" also refers to high-strength brick tile and paving slabs.

Hyperpressed Brick

Made from a special mixture of limestone, cement, and special dyes, it is a regularly shaped brick with perfect color, used for finishing and veneering work. Especially popular is brick with a non-uniform structure, which lets you style facade cladding to look like "ripped" stone.

Decorative possibilities of facing brick

Color

One of the strongest means of expression for creating the overall image of a home is color. Light and natural, dark and contrasting, with bright accents or blended into the landscape — how do you picture the facade of your home? Brick is no less versatile than natural stone, since white and red do not exhaust its color palette.

Facing bricks made by conventional or clinker technology most often have a natural shade of red, with the saturation and the hue itself depending on the impurities in the raw material and varying slightly from batch to batch. So in the masonry you will have to account for this feature of fired brick: to even out the color tone of the wall, you need to smooth out the natural variability of the stones by selecting them from several batches at once.

Hyperpressed bricks can be dyed any color the customer wishes, but keep in mind that the cement used as a binder gives the brick a whitish tone, muting the overall color of the brick wall. If a low-quality pigment was used, the brick can also "burn out" — lose its color.

For fired brick, there are also several ways to solve the "color problem" — engobing and glazing the stone.

Spraying

Interesting effects can be achieved by mechanically applying mineral grit to the surface, which gives the front face a micro-relief. This method is frequently used to produce clinker bricks, since the grit mixture sinters reliably to the ceramic during firing. The result is interesting color transitions from the natural brick color to the color of the applied mixture.

Such bricks tend to accumulate dirt on the surface (even more than textured bricks), so light colors require noticeable effort to keep the brick facade looking beautiful.

But you can enhance the expressiveness of a facade not only by using bricks of different shades, but also by using bricks of the same color with different textures on the face edges.

Relief

An equally expressive way to add character to a house is to use relief (textured) brick. Textured brick lets you vary the brickwork and emphasize certain elements of the facade (columns, corners, the framing of windows and doorways).

But it is worth remembering that the "rough stone" and "rock" textures, which so attractively recreate a natural fracture, noticeably reduce the strength of masonry on unfired bricks. A "ripped" front surface is covered with a network of microcracks that create areas of local internal stress, and the weaker middle of the brick becomes exposed to harsh climatic conditions. So it is better to avoid the extensive use of such bricks, or to use them under the reliable cover of a roof.

Ceramic or clinker facing brick is free of these drawbacks; adding relief does not reduce its mechanical or performance qualities. However, the textured surface tends to accumulate dust and soot, so such masonry will have to be cleaned more often than smooth brickwork.