Technical Notes 10B - Brick Sizes and Related Information
September 2001

Abstract:  This Technical Notes provides information on brick sizes and nomenclature.  Standard nomenclature for the twelve most common brick sizes is given.  The differences between nominal, specified and actual dimensions are explained.  Vertical and horizontal coursing tables for modular and non-modular sizes are provided.

Key Words:   actual dimension, brick, nominal dimension, size, specified dimension, standard nomenclature.

INTRODUCTION

Brick are available in many varied sizes and have been called by many different names.  This proliferation of sizes and names can be confusing for the designer and specifier.  The problem is further compounded by the need to distinguish between nominal, specified and actual dimensions.  Recent efforts led jointly by the Brick Industry Association and the National Association of Brick Distributors have led to the development of standard nomenclature for brick which represent roughly 90 percent of all sizes currently manufactured.

This Technical Notes lists the sizes of brick units generally available in the United States and presents the standard nomenclature for brick sizes.  The differences between nominal, specified and actual dimensions are explained.  Guidance is given on the recommended order in which brick dimensions should be listed.  Vertical and horizontal coursing tables are presented as an aid to the reader.  Other Technical Notes in this series provide tables for estimating brick masonry and information on modular brick masonry.

BRICK SIZES AND NOMENCLATURE

Brick sizes have varied over the centuries, but have always been similar to present day sizes.  The size of a brick has historically been small enough to be held in the hand, and most brick have remained small.  Brick is a building element with a human scale.  The use of small scale elements, such as brick, tends to break down massive expanses of wall into visually pleasing parts.  Furthermore, the use of oversized units alters the scale of the masonry unit in relation to the wall.  Because people have a perceived size of brick, the use of oversize units makes the wall appear smaller.

Over time new sizes have been developed to meet specific design, production or construction needs.  New types of construction have required new sizes, such as hollow units for reinforced masonry and larger units for increased economy.  Hollow units have varying coring patterns but typically are larger than standard or modular size and have larger cells to allow placement of vertical reinforcement.  Units with larger face dimensions allow the bricklayer to lay more square foot of wall per day.  Such units, compared to standard or modular size units, may increase the number of brick laid per day by over 50 percent.  However, as units get larger and heavier, a point of diminishing return exists.  Also, units with larger heights make filling the head joint with mortar more difficult.

In the past, a given brick size may have been known by several names due to regional variations.  In 1992, a joint committee of the Brick Industry Association and the National Association of Brick Distributors developed standard nomenclature for brick which represent roughly 90 percent of all sizes currently manufactured.  The standard nomenclature for brick sizes is presented in Table 1.  These terms were developed by a consensus process involving companies across the country.  The use of these standard terms when describing brick is strongly recommended.

¹1 in.=25.4; 1 ft=0.3m

²Common joint sizes used with length and width dimensions.  Joint thicknesses of bed joints vary based on vertical coursing and specified unit height.

³Specified dimensions may vary within this range from manufacturer to manufacturer.

Table 2 lists other brick sizes that are produced by a limited number of manufacturers.  Since clay is such a flexible medium, manufacturers can make many different sizes.  Also, modular and non-modular sizes are illustrated in Figs. 1 and 2, respectively.  The coring patterns shown in these figures are for illustrative purposes only.  Manufacturers incorporate cores and cells in solid and hollow brick in many different sizes and patterns.  The brick manufacturer should be consulted for information on sizes and coring patterns. 

¹1 in.=25.4; 1 ft=0.3m

²Common joint sizes used with length and width dimensions.  Joint thicknesses of bed joints vary based on vertical coursing and specified unit height.

³Specified dimensions may vary within this range from manufacturer to manufacturer.

BRICK DIMENSIONS

Brick are identified by three dimensions:  width, height and length.  Height and length are sometimes called face dimensions for these are the dimensions showing when the brick is laid as a stretcher.  The terms applied to brick positions as they are placed in a wall are shown in Fig. 3.  The shaded areas indicate the surfaces of the brick that are exposed.  Specifications and purchase orders should list brick dimensions in the standard order of width first, followed by height, then length.

Brick Positions in a Wall

FIG. 3

When specifying or designing with brick, it is important to understand the difference between nominal, specified and actual dimensions.  Nominal dimensions are most often used by the architect in modular construction.  In modular construction, all dimensions of the brick and other building elements are multiples of a given module.  Such dimensions are known as nominal dimensions.  For brick masonry the nominal dimension is equal to the specified unit dimension plus the intended mortar joint thickness.  The intended mortar joint thickness is the thickness required so that the unit plus joint thickness match the coursing module. In the inch-pound system of measurement, nominal brick dimensions are based on multiples (or fractions) of 4 in.  In the SI (metric) system, nominal brick dimensions are based on multiples of 100 mm.  For more information on modular construction see Technical Notes 10A Revised.

As the name implies, the specified dimension is the anticipated manufactured dimension.  It should be stated in project specifications and purchase orders.  Specified dimensions are used by the structural engineer in the rational design of brick masonry.  In non-modular construction, only the specified dimension should be used.  Tables 1 and 2 provide the specified and nominal dimensions, where applicable.

The actual dimension of a unit is the dimension as manufactured.  Actual dimensions may vary slightly from a specified size.  The actual dimensions of a brick must fall within the range of sizes defined by the specified dimensions plus or minus the specified dimensional tolerances.  Dimensional tolerances are found in the ASTM standard specifications for brick, such as ASTM C 216 Standard Specification for Facing Brick, or may be specified in the project documents.

COURSING

Although nominal dimensions are given only for modular brick, it should be noted that the heights of both modular and non-modular brick are the same.  This is because when modular sizes were first introduced, brick manufacturers were faced with the problem of supplying matching brick to existing non-modular construction.  From an appearance standpoint, most designers required that the vertical coursing of modular brick match the existing non-modular brick.  Thus, all brick are modular in height.  The vertical coursing information given in Tables 1 and 2 is a reflection of this fact.  Table 3 provides vertical dimensions based on the modular vertical coursing given in Tables 1 and 2.  For example, units with heights which course vertically 2 courses to 4 in. (2C = 4 in.) such as Roman size, should use column 1 of Table 3. The dimensions given in Table 3 include typical mortar joints of 3/8 in. to 1/2 in.  The actual mortar joint size can be determined from the vertical coursing information and the specified unit size.  For example, when coursing out with a modular height unit, the mortar bed joint is slightly larger than 3/8 in. and slightly less than 1/2 in., so that 3 courses of brick and mortar will equal the 8 in. module.  For most brick sizes the mortar bed joint will not be exactly 3/8 in. nor 1/2 in.  Table 3 is applicable to both modular and non-modular brick.  In this table, the brick are assumed to be positioned in the wall as stretchers or headers.

TABLE 3

VERTICAL COURSING^1,2

11 in.=25.4; 1 ft=0.3m

2Brick positioned in wall as stretchers or headers.

Horizontal coursing information is given in Table 4. The table includes coursing for both modular and non-modular brick.

Another useful tool for designers is the brick scale.  The brick scale is a coursing scale marked with multiples of common nominal brick sizes.  They come in a set which matches the most common architectural scales, 1/4 in. = 1 ft-0 in., 1/2 in. = 1 ft-0 in., etc.  Many brick manufacturers, brick distributors and masonry promotional groups provide brick scales to designers.

TABLE 4

Horizontal Coursing¹

¹1in.=25.4 mm; 1ft = 0.3m

CONCLUSION

This Technical Notes presents the standard nomenclature for brick sizes.  Information on brick sizes is given and the differences between nominal, specified and actual dimensions are explained.  Coursing tables for both modular and non-modular brick are provided.